Blue spruce's broken tip won't hinder future growth
Q: I purchased and planted two blue spruce trees. While they were being loaded at the store, the very top branch that sticks straight up broke off one of the trees. I didn't think much of it at the time, but now am worried that the top vertical branch might be responsible for the tree's growth. I'm not a tree expert, so I could be wrong about how the tree will grow taller. Without the center vertical branch, will my tree have stunted growth? The tree also was oozing a little sap where the top branch broke off. To protect it from insects, I put some tape on it. Should I leave it exposed to dry up and heal?
A: First, get the tape off the tree and then stop worrying about the future of the tree. One of the lateral branches, probably the longest one, will curve up and become the central leader with only a little crook in the stem to show for it. In time, the little crook will not be as noticeable. Sap flow in all living trees is normal at this time of year, so don't worry about that.
Q: My iris leaves are getting a light yellow color. It has been cool and wet here in South Dakota. I transplanted the iris plant and have not had it bloom in two seasons. Did I plant it too deeply? Do I need to apply some fungicide?
A: You probably planted it too deeply and possibly overwatered it. Dig and reset the plant. While you are doing that, cut off any decayed rhizomes back to fresh, disease-free flesh. Fungicides are not needed if you follow this procedure. Also, make sure the plant gets at least a half day of direct sunlight.
Q: I have a ficus hedge that has about a 5 percent leaf infestation by a dark, crawling insect. It lays tiny white eggs enclosed by a leaf. Can you tell me the insect and what form of insecticide would reach this pest? My gardener said he has sprayed twice, but there was no improvement. A: You need a systemic insecticide to control whatever this pest is. Look for a product that contains the active ingredient Imidacloprid. Bayer has a product on the market known as "Bayer Advanced Tree and Shrub Insect Control." There are other brands that carry the same ingredient if the Bayer product is not available where you shop.
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 ronald.smith @ndsu.edu.