Q. I know I'm probably a little overprotective, but several flowers have fallen off my three tomato plants. Is it an insect that clips them off without eating them? If so, I want to know how to kill this insect.
A. Whoa -- too many of our gardening problems are unfairly blamed on insects. Blossom drop is a common malady, usually caused by stress that prevents pollination and fertilization of flowers -- too hot, too dry, too cold, too windy, too much nitrogen fertilizer and so on. It can also be caused by diseases -- botrytis is one. Blossom drop is not a persistent or serious problem. Continue to keep your plants happy, and you will be rewarded with fruit.
Q. My husband thinks I'm crazy, but I know that something on my azaleas was biting my hands when I removed the dead flowers this past spring. While pruning the plants back recently, I did not detect any bites. What's going on?
A. You were indeed being bitten by the very small azalea plant bug. This fast-moving, red-colored predator of other insects is also a minor pest of azaleas. It feeds on pollen and foliage. It seems to attack and attempt to feed on anything that moves, including human flesh. No sprays are required to control this pest. Their numbers and activity subside a great deal after the bloom period.
Q. I have two wonderful vines on my patio that I planted because their red flowers are supposed to attract hummingbirds. The cardinal flower is growing and blooming beautifully. But the scarlet runner beans I bought at Thomas Jefferson's Monticello aren't doing so well. The leaf edges are turning brown and curling and tiny white bugs are flying around the plants. Is this whitefly, and if so what can I spray them with?
A. Potato leafhoppers are sucking the sap from the bean leaves and devitalizing your plants. Despite their name, they are fond of bean plants. This light-green, wedge-shaped pest is often worse on plants that are overfertilized with nitrogen. Control them with a thorough application of an organic insecticide -- either pyrethrum plus soap or neem plus oil. You may have to apply a second spray 5-7 days later. Your plants should grow out of the damage and produce red blooms.
THIS WEEK'S CHECKLIST
1. Avoid spraying pesticides on hot, humid days. Pesticides can burn foliage. Store pesticides in a cool location and mix up only the precise amount you need for a single application.
2. Provide some type of support for your sweet corn, eggplant and pepper plants to keep them from getting blown down or damaged in storms.
3. Contact the toll-free number below to order your copy of the Maryland Master Gardener Handbook. This 440-page guide contains color plates, diagnostic keys and information and practical tips on a wide range of home gardening topics.
Backyard Q&A is by Jon Traunfeld, regional specialist for the Home and Garden Information Center, Maryland Cooperative Extension Services of the University of Maryland. For additional information on these questions, or if you have questions of your own, call the center's hot line at 800-342-2507, or visit its Web site at www.agnr.umd.edu/users/hgic.