Ask An Expert

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

    A: 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

    April 18, 2017

    MIke Kuhns


     

    Q: 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: 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
    October 10, 2016

    Mike Kuhns

     


     

     

    Q: We live in Blanding, Utah and 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?

    San Juan County Utah
     

    A: 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
    September 12, 2016

    Mike Kuhns

     

    Q: 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: 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, Professor, Extension Forestry Specialist

    Mike Kuhns