Hortiscope: Cottonwood stump keeps sending up suckers
Q: We had a large cottonless cottonwood that we cut down. We had the tree removed and used a stump grinder to get rid of the stump. Our goal was to remove the tree and create a rose garden in its place. We used Roundup on the grass and my husband rototilled the area so we could move some dirt. In the process, he pulled up several roots from the cottonwood tree. We are getting suckers coming up everywhere. We pull them out, but more come up. Is there anything we can use on the soil to prevent more growth? We do not want to have to go to the expense of removing all of the dirt and replace it with clean topsoil if we don't have to, but it is beginning to seem that it is our only option.
A: If you can extend your patience a little longer, the growth will stop. Instead of pulling every one of them out, I suggest using a lyphosate-based (Roundup) material on the green sprouts. Eventually, you will overcome the maddening characteristic of this tree species. I don't recommend the total excavation or sterilization of the soil. There can be too many unintended consequences in addition to the expense.
Q: We have received a gift certificate from our local garden center to plant a tree in memory of my wife's dad passing away. We have an area in front of our house with a south and west exposure. Our two-story house is green, so we are looking at something with good color that can handle North Dakota winters. My first choice is a fall fiesta maple tree because of its fall colors. I would appreciate your thoughts on this. The garden center indicated that it would have both bare-root stock as well as potted trees available. The purchase of bare-root stock would allow for a larger tree and at a reduced price. If you get a moment, could you see if this would be a good choice? Other suggestions would be appreciated.
A: A very good gift in memory of your wife's dad! I would encourage you to take a bare-root tree. These get off to a quicker start and don't have the possible soil incompatibility problems with the soil it is being planted in. Planted properly and cared for the same way, you will enjoy this memorial gift!
Q: Is it OK to cut off the low branches of a Colorado spruce? They are on the ground and collect a ton of leaves. Thanks.
A: Absolutely! Those low-hanging branches also are hiding places for nature's furry friends, such as voles and bunnies, that crawl out and do damage to the ornamentals on your property. Skirting spruce, as this is referred to, will expose that lower trunk to allow for better air circulation and reduce hiding spots for some unwanted visitors.
To contact Ron Smith for answers to your questions, write to Ron Smith, NDSU Department of Plant Sciences, Dept. 7670, Box 6050, Fargo, ND 58108-6050 or e-mail firstname.lastname@example.org.