Q: I just read about rose rosette disease. Can we spray our Knockout roses with Volck oil spray in trying to keep the mites that spread this disease at bay? Elaine Sharp, email
A: Rose rosette affects all roses. The most common symptoms are distinct short red stems at the end of canes and huge numbers of thorns nearby. The disease is spread by tiny mites. The female mites hide in bark cracks in winter and lay their eggs in early spring. Horticultural oil sprays will keep numbers under control but they should start before budbreak (usually February), with a spray at budbreak (usually March) and repeat sprays every two weeks. Since the mites and the disease are not widespread yet, it is possible all of your work could be a waste of time. If your roses (or neighbor roses) don't exhibit symptoms there's no need to do anything.
Q: I have been storing fertilizer in a galvanized garbage can with a lid in the garage. Is this safe? Karen Klein, email
A: If you are worried about explosive potential, I very much doubt homeowner fertilizers would blow up. Open containers of fertilizer do not lose nutrients but they do absorb moisture from the air, making them difficult to use in a spreader. If the fertilizer is lumpy, it can be broken apart with a hammer and applied by hand. My father took the "bulk treatment" route. He had me spread old fertilizer on a sheet of tin roofing, and he ran over it with the family sedan!
Q: We recently bought a house with two huge brick retaining walls on either side of the pool deck. Each one is 12 feet high and 50 feet long. Is there a vine that will trail down the walls? Amy Patten Bishop, email
A: There are several good choices! Consider Carolina jessamine, Confederate jasmine, or American wisteria. Loosen the soil in the planting spot and add organic matter if it is heavy clay. Install the plants and watch for new growth. The vines will naturally want to grow up rather than down, so gently tie a small stone to the tip of lengthening tendrils to help them cascade over the walls.
Q: I read where you said that chipmunks are protected by state law. A local landscaper disagrees. What's the real answer on this? Marie Brumbach, email
A: The Official Code of Georgia says, "Except as otherwise provided by law, rule, or regulation, it shall be unlawful to hunt, trap, fish, take, possess, or transport any nongame species of wildlife." To me, "unlawful" means the state is protecting all nongame species, other than nuisance animals such as armadillos, coyotes, rats, etc. If the landscaper can correct me, I'd be glad to learn the new information.
Q: I ordered a bag of a blood meal online. It is very dark small granules. I tried to dissolve it in water. After a week, the stuff sits on the bottom of the glass, unaffected. Is this how blood meal is supposed to be? Yury Kupershtok, email
A: Although blood meal was originally a liquid, it was flash-dried at a processing plant. The drying process causes protein in the blood to coagulate into hard particles that resist wetting. When used as a fertilizer, soil organisms digest the blood meal particles and release the material in a nitrogen form that plants can absorb. That said, processors can make blood meal water-soluble by heating and chemically treating the rubbery particles. That's why some 12-0-0 blood meal product labels say "Contains 12% water-insoluble nitrogen" and others say "Contains 6% water-insoluble nitrogen plus 6% water-soluble nitrogen."
I feel sure you have the natural, untreated product. Use it in your garden at 8 pounds per 1,000 square feet. Dogs and other animals may find it attractive, so till it into the soil after applying.