QI have two varieties of sweet corn in my back yard, but there are very few ears of corn on 180-plus stalks of tall, green and tasseled sweet corn. I planted in warm, rich soil and fertilized at the prescribed times. My tomatoes and peppers are not yielding the quantity I was expecting either. What's wrong?
A The lack of ears on your otherwise healthy corn stalks is very puzzling. I talked to a corn breeder who was also puzzled, but here are a few possibilities.
You may just have very-late-maturing corn varieties. Your question was written in early August, so it's possible that if you have late varieties, and planted late, the ears hadn't formed yet. Remember also that corn produces only one or two ears per stalk. Corn needs to be planted in blocks, rather than one long row, so that adequate wind pollination can occur. Poor pollination usually results in poorly filled out ears, though, not a complete lack of ears. Extremely overcrowded corn might fail to produce ears, although the plants around the edge of the block would probably still produce a decent crop. Stalks should be about 1 foot apart in the row, and rows about 1 to 2feet apart.
While some crops have lower production if overfertilized, corn has a huge appetite for nitrogen, so I doubt that overfertilizing is the culprit. Too much nitrogen could reduce the yield of your tomatoes and peppers, though; high nitrogen causes the plant to produce lots and lots of dark green foliage, but at the expense of fruit production.
And, while we've had some wacky weather this summer, it generally seems to have been beneficial to corn. As long as the corn wasn't in standing water, all that rain in July was very good for corn growth. Overly soggy soil could have slowed down your pepper and tomato plants.
Q We planted seven Northern Lights azaleas in front of our home, along with some evergreens and other shrubs. Should I protect the azaleas with burlap from the cold winter winds? Also, is it normal that the azaleas have lost some leaves, while other leaves look spotted?
ANorthern Lights was the first of the Lights Series of hardy deciduous azaleas developed at the Minnesota Landscape Arboretum and released by the University of Minnesota. The woody stems are hardy to at least 35 degrees below zero and the flower buds to about 30 below zero. These azaleas do not require winter protection. However, rabbits and deer are quite fond of them, so you may need to encircle them with fencing if you have browsing problems.
The leaf spots and leaf dropping at this time of year may be from powdery mildew. This is a common fungal leaf disease. You may see definite whitish patches on the leaves when the fungus is actively infecting the leaf. You may also see purplish patches on the leaves from previous infections. Powdery mildew is mostly a cosmetic problem, but severe cases can cause premature leaf drop.
Good air circulation around the plants may reduce the incidence of powdery mildew. Also keep the azaleas in good health by making sure that the soil is acidified (use an acid fertilizer), that plants are kept well-watered during dry periods, and that the root zone is well-mulched with an organic material such as pine needles, shredded oak leaves or wood chips.
QI have a flower in my garden that I think I got from a friend, but I don't remember what it is. It is a lovely, light pink lily-type, but there are no leaves on the stem. I think there were leaves there earlier this summer. Any ideas?
A This sounds like Lycoris squamigera, a bulb plant in the lily family. This plant goes by a number of common names including resurrection lily, magic lily and (my favorite) naked ladies. All of these names refer to the fact that the flowers of this unusual plant spring up in late summer, seemingly from nowhere since there is no surrounding foliage. In fact, the unruly strap-shaped leaves of Lycoris appear in the spring, then die back by midsummer, leaving no evidence of the bulb's presence until the flower stalks appear. While usually listed as a zone 5 plant, it seems to do reasonably well here in zone 4, especially with the benefit of some winter mulch.
--Nancy Rose is a research horticulturist at the Minnesota Landscape Arboretum. She spends her spare time gardening, inside or outside, depending on the weather. Please address gardening questions to her at the Minnesota Landscape Arboretum, PO Box 39, Chanhassen, MN 55317. She will answer questions in this column only.