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Q & A

Q from Carlton, Salt Lake City, UT (received 5/2/20) -

I have a tannenbaum mugo pine tree planted in our front yard that is about three years old in Salt Lake City.  The tree began to yellow/brown last summer and this spring the pine needles are covered in what appears to be pine scale but looks smaller and browner than the photos of pine scale found online.  It appears they have a yellow inside when scraped off the needle.  The spots are over nearly the entire tree.  Is this indeed pine scale and, if so, what is the best treatment of the many available options?


A from Dr. Mike Kuhns, 
USU Extension Forester and Professor (sent 5/5/20) -

Carlton,

It appears that this is black pine needle scale. This can be successfully treated using a systemic insecticide. The insecticide is sprayed on the bark of the trunk, where it is taken up through deep bark furrows. It can also be injected into the soil, where it is taken up by the roots. The chemical name is dinotefuran and the common name is Safari.
 
Good luck.

Mike Kuhns
Mike Kuhns

Q from Jon, Syracruse, New York (received 5/1/20) -

Hello,

I live in Syracuse and I planted a Norway Maple in my backyard 3 years ago shortly after we built our home. I'm wondering if I need to (or can, for aesthetics) prune the tree? And if so, how do I do this, what is the best time to do so, etc.?

Thank you,
Jon


A from Gabrielle Harden, USU Forestry Extension Educator (sent 5/1/20) -
Hi Jon,

It is not necessary to prune your tree unless it is unhealthy, has hazardous branches, or needs shaping. If the tree is healthy and has good form (shape), I would refrain from pruning. Should you have the need to prune your maple tree, it is best to do so in winter or early spring when the tree is still dormant. Maples tend to give off a sap when pruned during that time of year, but it is nothing to cause alarm and will stop within a few days. If you're wanting the tree to be more shaped, you certainly could prune, but again, you should wait until winter when the tree is dormant. Where you cut the branch is dependent on what type of pruning you're trying to do. If you want to cut back a leader, you can prune the leader to the point where another branch is, given that the remaining branch is healthy and at least 1/3 the diameter of the branch being removed. If you want to remove a larger branch or lower branches, you must prune to the stem (trunk) of the tree. Pruning causes significant stress to a tree, so you will never want to prune off more than 25% of the trees leaf area. 

We have a very useful factsheet that will walk you through pruning in greater detail - including what tools to use, where to properly cut, etc. I suggest you look it over. https://forestry.usu.edu/news/utah-forest-facts/pruning-landscape-trees-an-overview


I hope this helps.

Gabrielle Harden


Q from Wendy, South Jordan, UT (received 4/30/20) - 

I have an Austrian pine that is turning yellow throughout the whole tree green and yellow mixed needles. It is 25 years old. I lost one three years ago, acted same way, had no sap tunnels or burrowing sign or holes in bark.  Saw no sign of that on the one we like at before either.  What can I do I have many of these same trees on my property?
Wendy Penrose


A from Dr. Mike Kuhns,
 USU Extension Forester and Professor (sent 5/5/20)  -

Wendy,

I can see from your photos that this tree is quite unhealthy. What is most unhealthy looking is the absence of needles. There are some needles but only the newest ones remain on the tree. There should always be at least 3 years-worth of needles on an evergreen conifer like a pine. The newest needles are near the tips of the branches and the oldest ones are farther back down the canopy. Every year the tree branches elongate from the buds in the spring, needles grow out as the branch grows, and a year’s worth of needles (the ones that are farthest in on the branch) die each fall. Though the tree is an evergreen because it always has green needles on it, the needles are not evergreen. 

Your tree has lost most of its needles that are older than one year, and the fact that even many of those needles are brown half way down their length is that much worse. And worse still, what live needle material is on the tree is yellow, not dark green as it should be.

I suspect that there is something wrong that involves the soil and the root system, so it would be good for you to dig around the base of the tree and see what you can find, while avoiding injuring woody roots as much as possible. A good way to do this is to use pressurized air to blast away the soil at the root collar, which is where the trunk meets the soil. However that requires the use of an airknife and a large compressor that I am guessing that you do not have. A slower alternative is to loosen up the soil near the root collar and vacuum it away with a shop vac. What you should look for is woody roots that are growing around the trunk base (girdling roots), a deeply buried root collar caused by planting too deep, or something with the soil itself (too wet, extremely compacted, etc.). If you do this, take some photos and send them to me.

Another thing to look at and to take photos of is branch growth for the past 10 years or so. A tree that is becoming as stressed as this one is will have slowing twig growth, and observing that growth can tell you a lot. To measure this growth you just start at the tip of as healthy a branch as you can find on the tree, then go back along the branch and find the point where the terminal bud was 1 year ago and measure the distance from the tip to that point. The way to find this point is to look for a change in appearance of the twig or branch bark, to look for linear scars that circle the stem where the bud scales were attached to it, and often you will have small twigs that branch off of the bigger branch at that same point. Then go back to where the terminal bud would have been 2 years ago and measure the growth from year 1 to year 2. Do this as far back as you can go. On a pine it is pretty easy to go back 10 years or more, and often you can actually age the tree if you go back to the limb and then the trunk and finally the root collar. There is a good chance that whatever is wrong with the tree has been developing for a long time, and doing this will tell you when the problem started by when the growth started to slow down, how abrupt the change in growth was, and whether it is getting worse recently.

Good luck.
Mike Kuhns
Mike Kuhns


Q from Mike, (received 4/30/20) -

I have a blue spruce approximately 30 feet tall that is losing its color and drying at the top. What could be the problem?


A from Dr. Mike Kuhns, USU Extension Forester and Professor (sent 5/1/20)  -

Mike,

This tree does not look very healthy, even where the foliage is not turning brown. It has been growing slowly (2-3” a year at the branch tips that are not being shaded by branches and needles higher up, versus 8-12” a year that a healthy spruce should be growing). It looks to me like it was doing well for quite a few years, and then the growth slowed for while – maybe for the last 15 years or so. I base this on the canopy shape (look at the photo with the redbud tree in it) where earlier in its life the tree was growing faster and the canopy was more upright and steep sided, while more recently, shown by the upper part of the canopy, the shape has been flattened, indicating slower growth.

The first and second pictures also look like there are several trees that are planted too close together. They are competing for light, which makes them lose their inside needles and branches. That is a natural thing, but if they are very close together none of them will get enough light. Trees that are too close together will compete for water as well. I think that lack of water is the main thing, though the brown part of the canopy could be a bark beetle attack brought on by water stress.

It won‘t be easy to get to, but the branches or the part of the trunk that are/is turning brown is the place that you would find bark beetles if they are there. There would be insect entry and exit holes through the bark and resin coming out in that area. In the mean time, though, I think that the tree needs more water in the summer and you should consider removing the least healthy trees that are competing the most with others.

Good luck.

Mike Kuhns
Mike Kuhns


Q from Christy, Taylorsville, UT (received 4/29/20)

There's a beautiful tree in my neighborhood in Taylorsville and I don't know what kind it is.
Thanks,

Christy


A from Dr. Mike Kuhns,
 
USU Extension Forester and Professor (sent 5/6/20) -

Christy,

That tree is a shrubby willow that has been grafted to an upright willow to achieve that somewhat odd form. In addition, the shrubby part is a willow with variegated leaves that are green and white, with some pink as well. It may be a variegated Japanese willow (Salix integra ‘Hakuro Nishiki’).

 
Mike Kuhns
Mike Kuhns

Q from David, Japan (received 4/28/20) -

Can a non-Asian tree species (e.g. an Oak) grow in Asia?

A from Gabrielle Harden, USU Forestry Extension Educator (sent 4/22/20) -

Yes. It really comes down to the growing conditions a species requires. Every species has different growing requirements, and it is important to understand those prior to planting. Things to consider include zone hardiness, soil pH, drainage, water requirements, and sun requirements. Similar to North America, Asia has a large variety of hardiness zones. Japan in particular ranges from Zone 3 in the northern region to 11 b on the south-eastern islands. A majority of oak trees can grow in hardiness zones 4-9, some in zone 3 and the Live Oak up to zone 10. The Bur Oak, for example, is very adaptable. This species can grow in a variety of soils (alkaline, acidic, sandy, clay, moist, well-draining). It can grow in zones 3-8 and prefers full sun.  Arborday.org is a useful website that provides growing information for a wide variety of tree species. 
 
Whenever you plant a non-native tree, it is important to consider whether or not it is considered invasive. Not all non-native species are invasive, but many are. Invasive trees can out-compete native species and drastically change the landscape. There are actually several oaks that are native to Japan, so you may consider those species first. 
 
I hope this helps.


Gabrielle Harden


Q from Ryan Davis, Arthropod Diagnostician, Utah Plant Pest Diagnostic Lab -

There is a housing development to the south of Moab that is experiencing pinyon dieback. I suspect that the mortality is due to infestation from Ips confusus, but my guess is that drought stress is adding to this issue. What are your thoughts on reducing drought stress on pinyon pines to reduce their attractiveness to bark beetles? Would you have specific recommendations for irrigating pinyon pines (frequency, drip type, amount of water, etc.)?  They want to keep their trees alive and I have given them many options to accomplish this, but I don't see insecticide applications to all trees every year as a good, sustainable solution. One aspect of an overall program would be to reduce drought stress on the pinyons.


A from Dr. Mike Kuhns,
 USU Extension Forester and Professor -

Ryan,

This exact thing happened all over central and southern Utah and throughout the Four Corners area about 15 years ago - https://www.fs.fed.us/rm/pubs_other/rmrs_2005_shaw_j002.pdf. If I had a few valuable pinyons I would consider spraying the trunks or soil applications of something appropriate (dinotefuran?) to ward off the beetles for awhile. But I also would irrigate in the hotter and drier part of the summer and maybe the fall as long as things stay abnormally dry. How much to irrigate is hard to say, but when they irrigate they should apply enough to have the water get down a foot deep or more. They can check how deep it is going by occasionally pushing a probe in in a non-rocky area. It will penetrate easily until it reaches dry soil.

Mike Kuhns
Mike Kuhns


Q from Frank, UT (received 4/27/20) -

I have a tree in my yard that Rocky Mountain Power wants to top or cut limbs in a L shape away from the power line. This tree is over 50 years old and at least 30 feet high. It is a healthy tree, Cone shaped I believe it of the Juniper family. I am afraid they are going to kill it with this technique. Please can you suggest a trim that would satisfy the utility but not harm my tree. 

A from Dr. Mike Kuhns, USU Extension Forester and Professor (sent 4/27/20) -

Frank,

Any tree that grows within a certain distance of a powerline must be pruned enough to maintain clearance. The clearance increases with higher voltage, with the lines that supply individual homes within neighborhoods needing much lower clearance than others. Yours might need 15 feet of clearance, but even then, they usually try to get more clearance since as soon as it starts growing again it will be too close.

Even though the L-shaped, V-shaped, and one-sided trees are odd looking, this pruning does not harm the tree as long as branches are removed back to the point that they meet another branch big enough to suppress sprouting and promoted healing. Typically that means that the branch that is removed is at least 1/3 of the diameter of the one that stays. The one that remains also needs to be healthy and vigorous.

I do think that it is good to contact the power company and the contractor doing the pruning and to let them know that you care about your tree and that you will keep an eye on the process. However, I think that it will not harm the tree.

Mike Kuhns
Mike Kuhns


Q from Sherri, Salt Lake City, UT (received 4/24/20) -

I live in SLC and have a 20 year honey locust that has been watered with the lawn so it has 5 large superficial roots.  Is it possible to cut out those superficial roots and have the tree survive?  Maybe cut out one a year to not shock the tree too much?

A from Dr. Mike Kuhns, USU Extension Forester and Professor (sent 4/25/20) -

Sherrie, This is a problem for you, but thankfully not for the tree.  If you are going to remove roots, you have the right idea — remove 1-2 a year. However, the roots are shallow because they can get what they need best at that level. Water, minerals, and oxygen all are needed by roots and all are most available shallow in the soil. Therefore, this will keep happening. The way to deal with emergent roots is to not try to grow anything like turf under that tree. Mulch the area under the tree where you are finding these roots with wood chips or bark.

Good luck.


Mike Kuhns
Mike Kuhns


Q from Robert Poll, South Jordan, UT (received 4/21/20) -

Would Prairie Horizon Manchurian Alder grow in South Jordan or is it too hot for it in the summer?

A from Gabrielle Harden, USU Forestry Extension Educator (sent 4/22/20) -

Robert,

Prairie Horizon Manchurian Alder is a very adaptable species. It is cold hardy to zone 3, so it can survive our coldest winters. This species is tolerant of everything from full sun to full shade, and both wet and dry conditions. Because of its ability to adapt, I believe it should grow just fine in South Jordan.
 
Best of luck,

Gabrielle Harden


Q from Bruce, Torrey, UT (received 4/6/20) -

I have property near Torrey Utah with many juniper trees. I'm the last couple of years I have had three die starting from the bottom branches up. I've removed them and in all three cases they were smaller trees growing next to healthier larger trees. I have one of the larger trees now having some lower branches bare. I would like to preserve it. Is there anything I can do to preserve it? Also anything I can do to protect other trees from developing the problem?


A from Dr. Mike Kuhns,
 USU Extension Forester and Professor (sent 4/7/20) -

Hi Bruce, I know what is removing the green foliage from the lower limbs of your junipers. And I bet that you are losing lots of other plants or portions of plants to the same factor. What you are seeing is the effects of deer feeding after a hard winter. Nearly all of the branches low down on the tree are alive, and they probably add a little new foliage to the bare area each year. However, in most years it would be denuded by spring. Above the height that deer can reach the tree canopy is fairly normal. 
 
This would be worse if there are a lot of deer and if they don’t have much to eat in winter. Also it can make it difficult or impossible for small trees to get big, because they have no foliage after a hard winter. Once a tree gets a good part of its canopy above the reach of deer then it will usually do well. The best way to get big trees in such a situation is to surround smaller trees with tubes of welded wire fencing. Just make sure that you want more junipers, given their tendency to burn.

Mike KuhnsMike Kuhns
Q from Rick, Bountiful, UT (received 3/24/20) -

I have some very sickly pine trees. A brief description is as of this year when I began to notice issues, first was the needle loss in a couple of the large trees, 80 to 90% has or is in the process of shedding. Also a couple and now 4 other pines are showing brown/yellowing in the last month. I looked closely and found a spongy feel in the bark of one type of pine, some bore holes in another. USU Forestry was mentioned to me by an alumni that said to get your recommend, he gave me his diagnosis as well.

Again, Thanks!
Rick


A from Dr. Mike Kuhns, USU Extension Forester and Professor (sent 3/25/20) -

Rick,

There are a few things going on here. The photo ending in 2305_n.jpg has a nearly dead blue spruce on the left, then a pine (probably an Austrian pine) right of middle, and another blue spruce on the right.  That looks OK, though maybe growing fairly slowly. I can’t tell what is going on with the spruce but I would bet that it is either soil (and therefore root) disturbance, and/or water stress. And if it is water stress then bark beetles could be involved.  It looks like it has been growing slowly for many years (maybe 10). It would be helpful to know how long ago the tree’s growth slowed down. This can be done by photographing fairly closeup the length of a good-sized branch from tip to trunk, overlapping the photos if you need to so I can see the point on the twig/branch where growth started from each year.

The other problem I see is a nearly dead bristlecone pine in the other two photos. I am guessing that it also is not getting enough water, though it also may have borers/bark beetles. There also is a very small spruce that has been shaded out by other trees. 

So send me some more photos and I will see what I can do.

Mike KuhnsMike Kuhns


Q from Luke, Missoula, MT (received 3/16/20) -

I read the article where you discussed the oldest English Walnut in Salt Lake. What else could you tell me about it? It is ‘Champion’ cultivar of English Walnut, correct? I’ll have to look at Salt Lake’s lowest winter temps of the last ten years. I’m in Missoula and am interested in growing some English walnuts. I’ve tried carpathian walnuts which are supposedly able to work in our zone 5a climate. But they didn’t make it. Did it get demolished? I’d like to collect seed from it in the fall.

Best,
Luke


A from Dr. Mike Kuhns, USU Extension Forester and Professor (sent 3/23/20) -

Luke,

The walnut you have read about is no particular cultivar. It has been designated the Utah state champion, meaning that it is the largest of its species found so far in Utah, using the measurement criteria of American Forests at https://forestry.usu.edu/tree-identification/hunt-for-big-trees

The tree is located in Ogden, about 30 miles north of Salt Lake City. I think of English walnut (‘Carpathian’ is a supposedly more cold hardy cultivar of English or Persian walnut) as fairly cold hardy. Where I live now (Cache County Utah) is considered a pretty cold place, but there are quite as few of them here, though I mainly notice them not in the lowest parts of Cache Valley, which are colder than the benches or terraces on the edges of the valley. 

Though the absolute lowest temperatures that are found in an area are often what sets the limit for plant survival through the winter, often variability in temperatures curing the winter, and especially how common unusually early and late hard frosts are is more limiting for species that are marginally cold hardy in an area. I would guess that you have a lot of variability in winter time temperatures and that you sometimes get very early or very late frosts.


Mike KuhnsMike Kuhns
Q from Kerstin Jones, Master Gardner, Salt Lake County, UT (received 2/27/20) - 

I work at a small nursery in West Jordan that has traditionally specialized in hanging pots and premium annuals. Last year they decided to venture into landscaping stock as well and brought in an assortment of trees and shrubs, some of which have overwintered on the lot.  

When surveying the stock yesterday we noticed many of the trees are severely rootbound in their pots. My employer asked if I would reach out to someone at extension and ask for some information regarding the process of resizing rootbound stock into larger pots. We recently lost our greenhouse manager and have yet to replace her, thus we are left without someone with this type of expertise. 

I am familiar with the process advocated by some extensions (CSU in particular) to cut back the entire circumference of the rootball an inch or so with a sharp spade or saw in order to treat circling roots before planting rootbound trees, but I'm wondering how well those trees would survive if they were put in a larger pot rather than planted right away.  Some of the trees also have girdling roots as large as 1.5 inches in diameter.  Can those be cut off without losing the tree?
Thank you for your time and help.  It is much appreciated,

Kerstin Jones

Photo of circling roots
Photo courtesy of Palm Beach County Extension and UF Laura Sanagorski

A from Dr. Mike Kuhns, USU Extension Forester and Professor (sent 3/09/20) -

Kerstin, 

Normal practice in dealing with potted trees that have been too long in the pot is simply to repot them in a bigger pot. This will make the resulting plants even more likely to have trunk-girdling roots later in life since there will be circling roots where the first pot was located and a second zone of circling roots that will develop at the second pot. It is not that apparently healthy trees with hidden deformed and defective root systems can’t be grown and sold to unsuspecting customers, and they may even do well after planting for up to 5 or more years. But eventually, when the tree’s trunk grows enough in diameter that it meets the first (or second) zone of circling roots which themselves are growing in diameter, then the circling roots become girdling roots and the tree starts to decline with no apparent reason. 

The best thing to do is to sell the plants before they get root bound in the first pot, though you did not say what form the owner bought the trees in – are they bare root liners that are planted in pots or are they already potted?  Either way, though, they need to be sold before they get root-bound in the first pot. Of course another way to grow bigger trees from small trees (this is especially good with liners) is to plant bare root trees in the soil in the ground instead of in a pot. Then you dig them with a tree spade in a couple of years. Such trees will be much better quality and healthier, with less chance of developing circling and girdling roots. They will also have the advantage of growing their root systems in soil instead of having them start out developing in soil-less potting material like ground bark or peat moss-based material, which results in more natural root growth and distribution. It also does away with problems that can be caused by interfaces between different root ball materials. 

If the nursery wants to repot the trees I like the method you described where you unpot them, cut an inch or so back into the root ball to remove the layer of circling roots that has formed there, and then place them in bigger pots. Still, though, it would be better to not let them get so root bound to begin with (and if you are getting some 1-1/2” diameter roots developing in the original root balls then they are definitely staying too long in the pot(s).
I hope that this helps.

Mike KuhnsMike Kuhns


Q from Kerstin Jones, Master Gardner, Salt Lake County, UT (received 2/27/20) - 

How soon do dormant trees need to be watered?

A from Dr. Mike Kuhns, USU Extension Forester and Professor (sent 3/09/20) - 

Kerstin,

I define dormancy as growth and metabolic or biochemical functions stopping in a plant or a part of a plant even though environmental conditions might allow for it. An example is a branch on a tree as it exists in late fall and through the winter with buds closed tight, no growth occurring (in the branch), sugars moved to where they need to be and turned into starch for storage through the winter, and antifreeze chemicals moved to or made where they are needed. This dormancy is usually caused by the plant sensing that the day length has shortened the required amount for that species to be ready to go dormant. The day length is determined by chemical changes that occur in tissues in the bud scales. These changes are actually caused by a change that happens as day length shortens that results in a change in the ratio of near infrared to far infrared light. When that ratio changes enough the plant goes dormant. Then even though the weather might warm, up a bit in December, the plant will stay dormant and won’t be fooled into coming out of dormancy by the weather changing, but will wait for the near infrared/far infrared ratio to tell it that spring is here. 

Roots, on the other hand don’t go dormant because they live in a more protected environment underground. The soil mass prevents quick temperature changes and sudden drying out. Therefore, roots grow whenever the soil is moist and the soil temperature is above about 40F. If the soil is too cold near the soil surface but is warm enough deeper in the soil then roots that are located deeper in the soil will be able to grow. What matters is the soil moisture and temperature at the root tip because the tips are where root growth happens.  

So, having said all of that, I also need to point out that more root growth is a good thing for trees. And since root growth occurs only in moist soil, then water to keep the soil moist at any time of year when the soil temperature at some depth will exceed 40F.
I hope that this helps.

Mike Kuhns
Mike Kuhns


Q from Rob, Grand Junction, CO - 

Would you happen to know of any contacts (university, city foresters, etc.) from areas that have had more experience working with populations of elm seed bug (Arocatus melanocephalus)?

I know this pest has been coined “only a nuisance”, but the calls from residents continue to come in on a daily basis (feels like I’m getting more ESB calls in Junction than I was getting EAB calls in Denver).

I understand Idaho and Utah infestations are a few years ahead of the infestation on the Western Slope of CO, and I always like to see what ideas / insight others may have to offer (especially those who’ve been dealing with issues longer).

Elm seed bug












A from Ryan Davis,
Arthropod Diagnostician, Utah Plant Pest Diagnostic Lab - 

Hi Rob, 

Our experience in Utah has been that when ESB were finally starting to get noticed (2014) they were a huge problem. My phone was ringing off the hook like never before for any pest - just like what you described. The high populations seemed to persist for 2-3 years, but now they have seemed to quiet down. Whitney Cranshaw (CSU) mentioned discussing a similar thing with others in the intermountain west. I suspect this will be a big problem at first and then may dissipate over time. Of course, their populations may be cyclic, but we'll just have to see about that. 

Concerning management: synthetic pyrethroids applied as a perimeter barrier treatment to a structure is the primary recommendation (including around windows, doors and even eaves, if necessary). Exclusion and vacuuming bugs in the structure is also important, but they are very small and can enter a structure seemingly through ANY hole. I have been recommending that people use white duct tape around their window screens to close that little gap between the screen frame and the window frame. They can easily get in that way and then squeeze between windows. I have personally used Demand CS, a microcencapsulated formulation of Lambda-Cyhalothrin for ESB management and it has worked very well and lasts for at least a month-and-a-half. I imagine that any microcap or wettable powder pyrethroid labeled for use as a perimeter barrier treatment would work well. Demand CS seems to be the leader in that category, however. Demand CS is the only product I know of with a special label for ESB. In Utah only the application site, not the insect, has to be listed on the insecticide label. 

FYI: we are not recommending treating trees or removing trees, unless the elms happen to be very isolated. As populations may equilibrate, it may be worth waiting it out a few years to see what happens. I have often wondered if imidacloprid applied in the late fall would allow chemical to arrive in the seeds and leaves in the spring, where these ESB feed while they are young. They also feed on leaves, so imidacloprid would end up there, too. ESB, of course, is not on imidacloprid labels, but certainly soft scales (i.e., European elm scale) is, if you need a labeled target pest on Siberian elm. 

Please send more questions if you have them; I am happy to help out. 

https://digitalcommons.usu.edu/cgi/viewcontent.cgi?article=2788&context=extension_curall

- Ryan Davis


Q from Alex - 

I have a tree question that I hope to get help on. I have two large trees in my yard. They seem to have fungal infection starting last year. This year it got particularly worse. One of the trees barely has leaves. I have been using anti-fungi spray called ferti-lome Liquid Systemic Fungicide II. It seemed to help last year and started to help this year. Besides doing this, what else can I do? I am worried that the tree may die this year.

Alex

fungus
fungus
A from Dr. Mike Kuhns, 
USU Extension Forester and Professor -

Alex,

Your tree is some sort of a sycamore or planetree (Platanus species). The disease is sycamore anthracnose and it is a fungus that attacks new leaves and twigs in the spring when the weather is cool and moist. Once the weather dries out and gets warm it goes away until next year. As far as I know systemic fungicides do not work for treating this disease, but spray application of fungicides like Bordeaux mixture works well. You normally don’t have to do it every year. Go to the USU fact sheet on anthracnose for details at https://utahpests.usu.edu/ipm/ornamental-pest-guide/diseases/anthracnose. Once the young leaves get infected by the fungus they fall off and the tree(s) put on a new set of leaves. 

Mike Kuhns
Mike Kuhns


Q from unknown -

What tree is this?

turkish tree hazelTurkish tree hazel

A from Dr. Mike Kuhns, USU Extension Forester and Professor -

Turkish hazel tree (Corylus colurna). Some trees take many years or even decades to reach sexual maturity, which includes flowering and bearing fruit. Most are grafted, which greatly speeds up the process, but especially when they are grown from seeds it can take a long time. Pinyon pines, for example, can take up to 30 years to bear cones and seeds.

Mike Kuhns
Mike Kuhns


Q from John, West Point, Davis County, UT -

I’m wondering if you would know what’s going on with my Yukon Bell pyracantha shrubs I planted just this spring, I think it was in April. They have been doing really well for the most part but all of the sudden most of them are looking really bad. Let me explain...
The new growth is yellow-green where it has normally been a dark green and it also is getting burned/crunchy. 
I water them 3x/week as was recommended by two nurseries. They aren’t getting better and a few of them actually seem worse. (Photos attached). Not sure if it’s my soil or what.

Any info you or anyone else could provide me with would be really helpful since I’m trying to not waste the money I spent on these plants with the intent to grow a hedge on a corner of my property.

yukon bell pyracantha
A from Dr. Mike Kuhns, USU Extension Forester and Professor -

John,

I am guessing iron chlorosis is the issue. Do you know your soil pH? If not you might want to get it tested by USU’s soil testing lab — see more at usual.usu.edu. If your pH is 7.5 or more that is probably the issue. Alternatively look around the neighborhood and see if many other plants are yellow. If so then that would confirm chlorosis. If it is chlorosis you can treat the soil yearly in spring with iron chelate, but it is expensive and you will have to do it forever. 

 
Chlorosis will be worse if you have compact soil and/or waterlogged soil, causing a lack of oxygen in the soil. Watering 3X a week seems a bit much to me. 
 
Mike Kuhns

Mike Kuhns


Q from Richard, Summit County, UT - 

Hello. I hope you don’t mind me sending you these photos of my sick aspen. We’ve had a few trees “die” and then leaf out again with new branches at the point where the main tree died. The new leaves are covered with sticky, but I don’t see aphids. They are planted in clay soil. Do you have any ideas about what the issue is and about treatment. 

sick aspen

A from Dr. Mike Kuhns, USU Extension Forester and Professor -

Richard,

Aspens have lots of problems, mostly because they do not put any energy into protecting themselves. Your trees appear to have poplar borers in them, which weakens and kills branches and trunks. The first picture looks like iron chlorosis, which is caused mainly by high soil pH. Stickiness would most likely be related to aphids, but stick material oozing from the trunk could be from the borer exit and entrance holes, but also possibly from stem canker, a fungal disease. 

You might want to read this fact sheet: https://forestry.usu.edu/files-ou/aspen-how-to-grow-a-good-tree-in-a-bad-situation.pdf

There really are no practical treatments for aspens because most of the problems they have are not readily treatable. For example, you can’t keep aspens from getting stem cankers and those are very serious problems for aspens. You can have trees sprayed with insecticide to coat the bark to discourage borer entry, but success is hit and miss and it can be quite expensive, plus you would have to do it every year or two. Also such sprays have no effect on borers already in the trees. Chlorosis is treatable by adding iron chelates to the soil, but again it would be fairly expensive and would have to be done every year. Actually the chlorotic leaves you send a picture of are likely chlorotic not due to the soil pH, but I suspect that branch or tree was very stressed by other problems. Irrigating is a good treatment, since most of aspens’ problems are made worse by water stress, but usually large scale irrigation is not practical and it won’t help the already heavily damaged trees. The best treatment is to cut down the oldest trees with the most problems, which will encourage sprouting from the roots. The new sprouts are much more vigorous than the old trees. You can retain the healthier of the big trees, then you can thin the sprouts. The factsheet I cited (above) describes this process.

Mike Kuhns 

kuhns


Q from Alex -

There are root like structures coming out of the ground in my yard. Do you know if they are normal or if they need treatment? They are making the lawn look weird. There is a large aspen tree nearby. Thanks a lot!

Alex

A from Dr. Mike Kuhns, USU Extension Forester and Professor - 

Alex,

As you know, aspens put out sprouts along their roots that have a stem above ground and roots below. The resulting plant is clonally produced, so it is genetically identical to the original plant. Regular mowing will keep these sprouts from growing and forming new trees. However, stems will try to form at certain spots along the roots, and will attempt to grow over and over, forming a zone of disorganized growth at the soil surface that becomes woody and that gets larger over time. You can get them out by pushing a sharp spade into the ground all the way around the growth and then cut any final roots that are going down by using the spade as a lever.  

Unfortunately, though this will remove the selected woody growths, the cutting of the roots will actually encourage additional sprouting along the roots that are cut. It actually causes the creation of separate trees, each of which will sprout. You can reduce the sprouting by using triclopyr herbicide (i.e. Ortho Brush-B-Gone or similar) or glyphosate (e.g. Roundup or similar). To avoid killing the grass near the growth, you should use a paint brush instead of spraying, applying the herbicide to all of the cut surfaces while they are still fresh (within hours is best for uptake). Doing this only makes sense though if you intend to remove the parent tree, since if you are careful to treat every cut surface there is a good chance that you will greatly weaken the parent tree. That is what I recommend doing, since the sprouts will keep on coming as long as that tree is alive. If you remove the tree you should also treat the stump with triclopyr right away. Also, though treating the stump and cut roots will weaken the remaining roots, you will need to go around your yard and your neighbors’ properties and cut any sprouts that have been left to grow and treat those stems. You need to do this quickly whenever a sprout forms. If you let one grow and get leaves on it, you will have the process starting all over again.

Good luck.
Mike Kuhns
kuhns


Q from Joan -

I have three trees in my yard, a maple, a red bud and a honey locust (I think). The trees appear healthy but the people who do my lawn care want to sell me a package of at least 4 treatments, nutrients, oils, etc. Do I need to purchase a preventative tree care plan for healthy non-fruit trees? Also, could you let me know what I should look for in an arborist for trimming? Any suggestions?  I would also like information on the lunch webinar series. I don’t know much about tree care, or gardening for that matter, and I would like to learn more. Thanks.
-Joan

 

A from Dr. Mike Kuhns, USU Extension Forester and Professor (sent 6/07/18) -

Joan,

The number one thing that all trees need is adequate water. Of the species you mention, the honeylocust and the redbud are fairly drought hardy and the maple depends on what species of maple it is. Trees rarely need fertilizer (nutrients) beyond what they can get from normal Utah soil. I have no knowledge of how you could help a tree by adding oils, other than horticultural oils that are used sometimes to smother insects. I would keep my money in my pocket.


If your trees need pruning you can do it yourself (see https://forestry.usu.edu/files-ou/pruning-landscape-trees-an-overview.pdf), or you can hire someone, preferably an ISA Certified Arborist (not a licensed arborist – that just means they have a business license). You can get webinar info at our webinars page.

Mike Kuhns

Mike Kuhns


Q from Maryanne A, Summit County, UT - 

Hello, my husband and I live in on the Wanship/Hoytsville line, about 15 minutes from Kimball Junction and Park City.  We have several Scotch Pine trees which are between 50 and 60 years of age, beautiful trees in our front yard. Last fall we noticed the last tree in the row was losing needles, and the tree branches were turning brown. Most alarmingly, the upper part of the trunk began to lose its bark. I called the county agent and he suggested that we soak the tree root ball well just before the ground froze, which we did. This spring we lost the tree. We fear that it is bark beetle.  We've taken it out, but can now see the beginnings of loss of bark in the upper part of two more trees.  Is there anything we can do to save these beautiful threes? Attached is a picture of one of the upper branches of the tree that went entirely brown and which we cut down.  Does this look like the awful work of bark beetles?  If there is anything I can treat the upper bark with to kill or halt the beetles, I will do it!  Thank you for any help!

Best

Maryanne A.

porcupine damage
porcupine damage

A from Dr. Mike Kuhns, USU Extension Forester and Professor (sent 5/11/18) - 

Maryanne,

This doesn't look quite right to be due to bark beetle feeding. It looks more like what you would get from an animal scraping the bark and cambium with its teeth. Of course if that were to happen the bark would come off as the feeding was occurring. If bark beetles attack a tree they make an entry hole, tunnel within the inner bark in a predictable pattern that varies by the type of beetle, they lay eggs in their tunnels, the eggs hatch and the young larvae make tunnels that also have a predictable pattern and are smaller in diameter than the adults' tunnels. Eventually they mature and tunnel out through the bark leaving an exit hole. The tunneling of many attacking insects eventually weakens and then kills the tree, but the bark does not come off until that part of the tree is dead. What I am seeing on this tree does not look like bark beetle tunnels. It looks more like the scraping of teeth.

Animals (non-insects) that scrape off bark to feed include porcupines, squirrels, deer, elk, horses, rabbits, mice, and voles. It might seem that you would notice a porcupine feeding, but they mainly feed at night, so you might not. You also might not notice squirrels as they were feeding, and rabbits, mice, voles, and large ungulates (deer and elk) would not be able to reach that far up.
    

If I had to guess I would say that it is bark stripping and not insect damage, and that it is porcupines rather than squirrels because the tooth marks look too big to be from squirrels. To see what their feeding looks like search Google for "porcupine bark feeding" and click on the Images button.

   

It will be difficult to control porcupine damage. It is probably not legal to trap them or shoot them, though your UDWR local office might have suggestions. Your area is covered by the UDWR office in Ogden, phone number (801) 476-2740.  If you search the web for "porcupine control" most of the suggestions focus on live trapping. There is a good article at http://icwdm.org/handbook/rodents/Porcupines.asp.

 

Mike Kuhns

Mike Kuhns


Q from Freddy W. - 

Good afternoon,

I'm not sure if you're the proper person to contact, but I had a question. I found this in the Coral Pink Sand Dunes Area and wasn't sure what it was. It's about 3 inches long. We believe it's a type of fungus and people have suggested it's a magnolia. I'm not native to Utah or the Kanab area so I'm not sure if magnolia's grow down there. If you can help identify it or direct me to someone who could I'd be very grateful.

Thank you so much,
Freddy W.

ask an expert

 

A from Dr. Mike Kuhns, USU Extension Forester and Professor (sent 4/16/18) -

Freddy,

It is not a magnolia. There are planted magnolias in Utah but none in the wild. I believe that it is the beginning of a witches broom or something like that. A witches broom is simply an area of abnormal growth that forms on a woody plant and leads to a proliferation of growth in one area. It will tend to grow in that abnormal state year after year, which can cause the shoot that it is growing from to die due to disruption of the vascular system. That may have happened here. Witches brooms and other abnormal growth can form as a reaction to a virus or another pathogen or for no apparent reason, but all likely happen due to a genetic mutation. Burls on tree trunks are another form of such a mutation. Sometimes the shoot grows in a flattened form which is called fasciation.

These growths are essentially plant cancers. They will continue to grow until they can no longer be supported by the plant they are attached to, and then they will break off or they will lose their source of water and other materials they need to survive as they disrupt the vascular system. Generally I don’t think that they are contagious, and if you prune them off below their point of attachment they will die and will not come back, at least on that shoot.

These types of growths happen on many different types of plants and on a particular plant they can happen in association with different parts of the plants, but usually are associated with the formation of vegetative or reproductive buds. This one looks like it could be either of those. You would have to pick it apart and look for reproductive structures to tell which it is. If you had more of the plant farther down where it is growing normally I could tell you what plant it is. It looks like it would be from an angiosperm, not as gymnosperm. It could be from a willow.

Mike Kuhns

Mike Kuhns


Q from Sharon, Spokane, WA - 

Is there anything known about the “tipping point” or ways to predict native trees decline due to drought stress? Most of our native trees and plants are drought tolerant, but in recent years we have had longer periods of no precipitation, high temperatures, big fire seasons, and have been seeing more symptoms of drought stress and other insect/disease problems combining to cause tree death. This is in native forests and rural situations. ( inland northwest- montana, Idaho eastern Washington. Primarily ponderosa pine, but some other species like doug fir and cedar also).

Sharon

A from Dr. Mike Kuhns, USU Extension Forester and Professor (sent 11/29/17)-

Sharon,

There is a tipping point, but it would be different for each species or forest type and what you would measure to indicate whether this point has been reached would vary. If the trees are coniferous evergreens then the best indicator may be how many years worth of needles are on the tree. Severely stressed trees will often lose last year’s needles before the next growing season is over. Also stem (trunk) diameter growth is a good measure of stress. Slow growth is a sign of stress. Finally, susceptibility to insect attack is a good indicator of stress.

Mike Kuhns

Mike Kuhns


Q from Tom, Cottonwood Heights, UT - 

I live in Cottonwood Heights but am currently visiting friends in the southwest of France, in Toulouse. Here is a question you have probably never had before! In the north of Spain, in the Basque region, they make a walking stick from a wood Neflier (makhila is the generic name for the walking stick). Is there any equivalent of Neflier in the US?

Thanks for your help

-Tom

A from Dr. Mike Kuhns, USU Extension Forester and Professor (sent 10/3/17) - 

Tom,

Yes. Neflier is a French name for the genus Crataegus or hawthorn. The Spanish name is Espino. Utah has one native hawthorn – black hawthorn or Crataegus douglasii. I see it all over the place at fairly low elevations where there is some water. It is a muiltistemmed tree or a dense shrub, but some species of hawthorns are tree-like, and many of these are planted in Utah. To learn more about hawthorns go to our Tree Browser website at www.treebrowser.org.

Mike Kuhns

Mike Kuhns


Q from Judy - 
A cut aspen tree, with the stump still in the ground, is sending out a huge amount of shoots. Can anything be done to kill the stump, outside of removing it? Can the shoots be killed with some product? Help!

-Judy

A from Dr. Mike Kuhns, USU Extension Forester and Professor (sent 7/7/17) - 

Judy,

Not really. Just cut it down and spray triclopyr (e.g. Ortho Brush-B-Gone or Poison-ivy Killer) or glyphosate (i.e. Roundup) on the stump surface (it is better if the stump is freshly cut), and cut off any sprouts and treat their cut surfaces too. It may take several rounds of this until everything is dead.

Mike Kuhns

Dr. Mike Kuhns


Q from unknown - 

I have a Kentucky Coffee tree in my landscape.  It was healthy last year, but this spring just as the leaves were emerging, it was hit by a frost (about 30 degrees F) which killed the newly emerging leaves.  A few weeks later new buds had formed but as the leaves emerged they are deformed, almost looking like epinasty from 2 4 D (but no herbicides have been used and the tree branches as 6+ feet above the ground).  All leaves are affected.  All the information I find on the web indicates that the Kentucky coffee tree is rarely affected by pest or disease, but something is obviously wrong.  I have included 2 photos of leaves.  Do you have any ideas what is wrong?

Kentucky Coffee Tree 1Kentucky Coffee Tree 2

A from Dr. Mike Kuhns, USU Extension Forester and Professor (sent 6/29/17) -

John,

I thought this was going to be a case of deformation due to frost damage of tissues still in the buds, but after looking at the pictures, I don’t think so. For one thing, the type of damage that frost causes usually does not include twisting like this. It is more small holes and bumps. Also it doesn’t make sense since new leaves produced after the original leaves were killed would be from tissues produced after the frost. So I am still thinking herbicide. 2,4-D can drift quite a bit, especially on warm days when it volatilizes. The amine form is the most common and is not as bad as the esters (there are low and high vol esters).

Some plants develop cancer-like growths on some of their tissues and these growths often involve flattening and twisting. Though this is not completely understood, it appears to involve genetic changes in the tissue in certain areas on the plant, and pruning off those areas gets rid of the abnormal tissue in that area. These genetic changes seem to be triggered by viruses, maybe bacteria and fungi, certain insects (forming galls), etc. I don’t know if frost damage could trigger this kind of thing. There is a good article on this in the NY Times at www.nytimes.com/2015/07/28/science/cellular-cheaters-give-rise-to-cancer.html. I have attached a picture of one type of such growth called fasciation, that involves flattening of branches. This one is on a juniper here on campus. I also attached a photo of some frost damage on a maple.

Juniper

FrostI recommend that you watch it and see what happens. It won’t spread to other plants and it may go away. There is nothing you can do about it, so you might as well let it go for awhile. If you do, please keep me informed.

Mike Kuhns

Mike Kuhns


Q from unknown -

I planted the Bur in March and have been excited to see it leaf out. I have noticed that a good number of the leaves aren't the typical dark green that I've seen, and am attributing this to stress. That being said, the leaves are a mixture of light green to yellow/bronze. The veins themselves are still green and the leaves don't appear to be wilting so far. I've also read that this could be a sign of over or under watering the tree. I've attached a photo to better highlight what I am seeing. Any help you could offer to get this tree in good shape would be appreciated.

Bur Oak

A from Dr. Mike Kuhns, USU Extension Forester and Professor (sent 5/19/17) -

The leaves look perfect for this time of year. Many plant leaves have some red in them as they emerge, but before they mature. The chlorophyll that will absorb sunlight and use that energy (along with CO2 and water) to make food through photosynthesis is not fully mature at first, and the sun would bleach the chlorophyll without some protection. The red pigment is there to absorb that light and protect the chlorophyll until it can absorb light on its own and use the energy. Some trees retain the red pigment and are more-or-less red all summer, while with others it fades and the leaves end up pure green. Your bur oak will be the latter. In a cool, prolonged spring like we are having this year, the red may hang around longer since the development of the chlorophyll is delayed.

Mike Kuhns 

Mike Kuhns


Q from unknown (full conversation) -

When is the best time of year to plant trees? 

A from Dr. Mike Kuhns, USU Extension Forester and Professor (sent 5/9/17) -

Trees are best planted when they are still dormant with tight, unopened buds in the early to mid-spring after the soil has thawed. Cool temperatures and good soil moisture in the spring help trees get established. Fall planting also works well for many species, though watering is critical if the fall is dry. Summer planting of B&B (balled-and-burlapped) and container plants can be successful, though hot temperatures, dry conditions, and non-dormant trees makes good care especially important and survival less sure. Bare root trees should only be planted in spring while still dormant.

Q - Of those types of trees, which is best?

A - Landscape trees and shrubs can be obtained in four basic types: balled and burlapped (B&B), container/potted, bare-root, and tree-spaded. Each type has advantages and disadvantages and none is ideal for all situations. Bare-root will give the tree the most naturally formed root system and they are less expensive, but they are not commonly available from nurseries. B&B trees are good because they have been grown for several years in soil and are more likely than potted trees to have a well-distributed root ball. Potted or containerized trees are the worst, with it much more likely that the tree will develop root system problems like girdling roots and buried root collars. Spaded trees are good but may not be available.

Q - How large does the root ball need to be?

A: With all four types you need to have an adequate root system – a good rule-of-thumb is that the root system, root ball, or container diameter or spread should be 10 inches to 12 inches for every inch of stem caliper (diameter at ground-line just above any basal swell). Therefore, a 3-inch caliper tree should have a 30 inch to 36 inch wide root ball as a minimum. Root ball depth is not as critical as width but should be larger for larger trees.

Mike Kuhns

Mike Kuhns


Q from unknown - 

We have cut down a maple, sycamore and ash tree that were growing in our yard and roots had spread on the surface causing the grass to die. How far down do we need to remove the roots so grass can grow? 

A from Dr. Mike Kuhns, USU Extension Forester and Professor (sent 4/18/17) - 

The roots did not kill the grass. Shade from the tree did, along with competition from the tree for water and space to grow. Just remove the stump and roots down a few inches so you can put some soil down so the grass roots have soil to grow in.

Mike Kuhns

Mike Kuhns


 

Q from unknown -

Is the blue spruce on my property at risk for bark beetle infestation? I go every year to chop down beetle killed trees in the Uintas, (pond pine, white fir), I bring it home, and use it for firewood. I have a blue spruce that I'm concerned may become infected. 

A from Dr. Darren McAvoy, USU Extension Forester and Professor (sent 3/7/17) -

You are only putting your spruce at risk if you bring spruce logs down to your property; beetles are species specific. Bringing ponderosa and white fir will not threaten the spruce. Hope this helps.

Darren McAvoy

Darren McAvoy


Q from unknown, Grantsville, UT -

Hi, we live in Grantsville out past Tooele and we were wondering if  it is too early to prune our Peach and apple trees. Could you help us on this?

A from Brent Black, USU Extension Fruit Specialist and Professor (sent 3/7/17) -

It is not too early to prune apples, and probably not too early for peach. Because pruning can result in a slight loss of cold hardiness in the remaining branches, it is generally recommended that you don’t prune until the risk of severe cold has passed. Many commercial growers are now pruning peaches, but also watching the weather. If there are extreme cold temperatures (single digits) in the forecast, then stop pruning until the cold weather has passed.

Brent Black

Brent Black


Q from unknown, Delta, UT -

I recently purchased a lot and built a house in Delta, UT.  The soil here is very alkaline and I am trying to come up with some sort of plan as to how I will be able to get some trees to grow. I've heard that green ash can do well in this environment but I'm having some difficulty in finding any good info on what and how to plant.  Please, if you have any suggestions or could even point me towards some literature on this topic I would be very grateful.

Thank you for your time

A from Grant Cardon, USU Extension Soils Specialist and Professor -

Green Ash does well in high pH soils in Utah.  Planting really is nothing out of the normal, make sure that the hole you plant in is 2 to 3 times larger than the root ball and mix the excavated soil with a good compost to enhance the organic matter content of the repacked soil.  This will improve the soil structure over time around the roots and the tree should do well.  If planted in with a lawn, the regular fertilization of the lawn will provide sufficient nutrition to the tree as well.  Be sure not to cover the crown area of the tree (the point at which the shoot and root join).  This can cause rotting of the bark above the crown and the tree will be susceptible to fungal and bacterial disease.

If you are interested in other trees that can tolerate alkaline conditions and want to preview other features such as fall color, spring bloom, decorative bark and other desirable features you can consult the on-line Utah Tree Browser put together by our Extension Urban Forestry group.  The browser can be found at:

http://treebrowser.org/

One piece of education and advice.  Utah soils are alkaline because of the large quantity of Calcium Carbonate (or lime) that they contain naturally.  Utah soils can contain anywhere from 15 to 40+ % lime by weight.  This lime is a very reactive buffer against pH change and consumes large quantities of acid as it dissolves.  One would have to dissolve ALL the lime in the soil before pH can be lowered.  In practical terms, this is impossible given the scale of the requirement for acid to accomplish this.  One percent by weight of an acre 12 inches deep is 40,000 lbs or 20 tons.  Utah soils therefore contain 15-40 times 20 tons of lime in the top foot of an acre of land.  So, you can see the problem of scale we are up against.  Even our irrigation water contains large quantities of dissolved lime (hence the nice hard water deposits on our faucets and drinking glasses and our windows after the sprinkler wets them!).  So, there is just too much pH buffer in our systems to ever try to adjust pH.  Better to select plants that are tolerant of alkaline conditions.

Hope that helps.

Grant Cardon

 

Grant Cardon


Q from Mario Medici, Tuxedo, NY -

I’m a hiker (and hike leader) and recently came across a pine tree that I can’t identify. It is located in Sterling Forest State Park, Tuxedo NY, and is one of its kind that I have found. It has a dark green, almost blue, glossy, thick, 5-6 inch needle, with three needles to a bundle (fascicle). I know its not a white pine (there are lots of them and they have 5 needles to a bundle) and my research seems to believe its a Pinus Ponderosa or Pinus Jeffery (pine), neither of which are native to this area and are predominately in CA and the far west region of the USA. 

Could it be someone planted it? If it helps, the tree is near Sterling Lake, once a mining area for magnetite.

This is driving me crazy!! Can you help? 

-Mario Medici

A from Dr. Mike Kuhns, USU Extension Forester and Professor (sent 10/10/16) -

Actually, that is a better description of Austrian pine (Pinus nigra). They have needles in 3s (ponderosa is in 2s and 3s), and 5-6" long needles (ponderosa needles are longer). If you have cones, ponderosa has sharp prickles on the tip of each scale. Austrian has a bump, but no prickle. And mature buds on an Austrian pine are white, while they are reddish-brown on ponderosa.

Mike Kuhns

Mike Kuhns


Q from Gene Tabish, Murray, UT -

I have an Elm tree that is dripping a clear liquid on my lawn. The areas of the lawn affected by the liquid have been killed. Do you have any suggestions on how to remedy this?

Thank you,

Gene Tabish

A from Dr. Mike Kuhns, USU Extension Forester and Professor (sent 10/2/16) -

Gene, the only thing that might do this is bacterial slime flux that oozes out of wounds in elms, willows, and some other trees. Normally the waste from this disease runs down the trunk from old pruning wounds and eventually kills grass. I haven't seen this in the form of dripping material, but I suppose it could happen.

Regardless, there is nothing you can do about the disease, and it doesn't harm the tree much. If you mulch under the tree there won't be any grass to kill.

Mike Kuhns

Mike Kuhns


Q from unknown, Blanding, UT, San Juan County -

We planted 52 new 4-6 ft. trees in March 2016. We have been watering them 3 times a week (about 10 gallons per watering). Now that it has cooled off and turning fall, how often do they need watered?

 

A from Dr. Mike Kuhns, USU Extension Forester and Professor (sent 9/12/16) -

Roots will grow as long as the soil they are in is moist and while the soil temperature is above 40 degrees F. And it is good for roots to keep growing because it will speed the trees' recovery from transplant shock. But once it cools off enough then little water will be transpired from vegetation and it won't take much to keep the soil moist. So as long as it stays cool you can back off to maybe once every couple of weeks, or don't water at all if you get significant precipitation. A good way to tell how deep you are watering if the soil is not too rocky is to use a probe like a long screwdriver or a steel rod welded to a handle to form a tee. It will penetrate moist soil and will stop when it reaches dry soil. You would like to water enough that the soil is moist down to at least a foot.

Mike Kuhns

Mike Kuhns


 Q from unknown -

I have an ornamental weeping cherry, and I believe it was grafted. I would like to prune it so it can retain it's weeping form. What do you suggest?

A from Dr. Mike Kuhns, USU Extension Forester and Professor - 

With grafted plants it is important that you know what is the rootstock and what is the top. Often plants are grafted just above ground with one plant that has it's top completely removed, the rootstock, and one or more plants that have no roots but are desired for traits that their tops have. In the case of almost any trees that have a weeping top and an upright stem, you actually have 3 or more plants -- the rootstock, the upright stem (which may be a part of the rootstock), and the weeping part. And on some ornamental cherries there may be several top branches attached to the top of the upright stem.

Any of the parts of such a plant may form buds and those buds can grow new top material, but if you want to retain the grafted form as it was meant to be, you have to prune off such shoots. In some cases, like with twisted forms, the twisted top may actually grow slower, and if a straight shoots come off of the rootstock, they may eventually shade out the twisted parts.

I hope that this helps.

Mike Kuhns

Mike Kuhns