Prune straggling petunias and fertilize for best results
Q: I have a snowball vibrunum bush. For the past two years, the leaves have started turning black and curling up. Some of the flower buds did the same thing. I noticed ants all over it, so I sprayed it with an insect spray and sprinkled ant powder around the bottom. The ants seem to be gone now. Is the problem happening because of the ants or is there some other disease that could be causing it?
A: The ants are going after the aphids that are attracted to this shrub. Spraying to control the aphids also will eliminate the ants. The ants milk the aphids of their honeydew and use it as a source of food.
Q: I like planting trailing and regular petunias in pots. I always put the pots in the sun, but sometimes they look a little straggly. I like the more rounded, compact look. Is there a special technique to pinching them? I try to deadhead the non-trailing plants, which helps a little.
A: Go ahead and prune the stragglers back somewhat to get them to bush out. Don't be afraid to use a water-soluble fertilizer, such as Miracle-Gro, about every other week to keep the plants flourishing. Petunias are heavy feeders, but the reward is their beauty for doing so.
Q: The mankana ash tree on my boulevard is toast. Any recommendations for a replacement tree? I don't want anything that drops seeds or pods, suckers and definitely don't want to plant another ash tree. When I look around town, some of the nicest trees are elms and linden big leaf trees. Thanks as always for your expert advice.
A: Lindens are great trees to have. I have a Redmond linden in my front yard, but it does drop flower petals and the fruit (nutlets) that follow. Why not consider a hackberry tree? Also, the new elm introductions have been selected for their Dutch elm disease resistance. Other trees you might want to consider are autumn blaze (hybrid maple) or northern acclaim, which is a new seedless honey locust that grows fast and turns a beautiful yellow in the fall
Q: I gave my wife some purple calla lilies a month or so ago. She planted the lilies in a pot. Are these the same as peace lillies? Can I plant them in my yard or are they better off in a pot in my house? Are these perennials or annuals? Should the lilies be planted in a shaded or sunny area?
A: The peace lily is a spathiphyllum spp. It is appropriately named because of the spadix that is in the middle of the flower. The calla lily is a zantedeschia spp. that has flowers that are more cuplike. The lilies are better off in a pot in your house. In the tropics, lilies are perennials, but in this part of the country, they would be dead after the first frost. They will take full sun or semishade.
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.