Q: Will neem oil work to kill sawflies on my roses? — Amber Piccolo, email
A: Sawfly larvae can quickly riddle a rose leaf. The "worms" chew the leaves and leave characteristic holes. Neem oil, spinosad, and insecticidal soap are all good organic means of control. Apply as early as you can in the morning or late in the evening to miss the beneficial insects that are also present. If you're an early riser, simply turning rose leaves to examine the backside will usually reveal the sawfly larvae at work, where they can be squished with your fingers.
Q: I see pine seedlings all over. How do I get rid of them? — Cindy Hunt, Cobb County
A: Pine seedlings usually die before growing much larger. Arborist Chris Hastings (arbormedics.com) said he believes pines can have cyclical seed production just like oaks, a phenomenon sometimes called "mast years." Last year's spring pollination was particularly successful; remember how bad the pine pollen was? Plus, our wet, cold winter acted nicely to prepare the seeds for germination. Pull what you can and spray the rest with weed killer.
Q: For a number of years I've had a problem with some sort of borer getting into the stems of my hydrangeas. What can I do to get rid of them? — Carolyn Dominy, Macon
A: There are any number of cane-boring insect larvae, some of which affect hydrangea. Insecticides don't offer much control. The best therapy is to cut a cane successively lower until you find the spot where damage stops. The borer is above that point. Collect all of your clippings and put them in the garbage. It may take a couple of years, but regularly removing the grubs will result in a lower population.
Q: On a recent radio show, you talked about placing cheesecloth over squash plants until flowers appear to keep squash vine borers at bay. Where can I buy cheesecloth big enough to cover the plants? — Mike Childers, email
A: I was wrong to recommend cheesecloth. It is not wide enough to make an effective cover. Instead, ask for floating row cover or frost cloth at your local nursery. This lightweight polyester material can be draped over squash plants until blooms appear.
Q: Do we have wild elderberries around here? I'd like to harvest the berries to make something edible. More importantly, how do I identify the blooming plant? — Daniel Vines, east Cobb
A: You have a great local resource: the Georgia Native Plant Society (gnps.org). They sponsor regular plant rescue outings, led by knowledgeable guides. I feel sure they could direct you to a rescue outing where you might find elderberries growing that you can transplant to your landscape.
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