Q: I’m trying to find a heat-hardy lilac for my New York state friend who lives in Forsyth County. Amy Dyer, email
A: The key element that lilacs lack in the South is chilling hours during the winter. Most lilacs require more than 2,000 hours of temperatures below 45 degrees to bloom. The solution is to find lilac selections that do not need so much cold weather. Ask local nurseries if they can find for you 'Lavender Lady,' 'Blue Boy,' 'Dark Knight,' 'Miss Kim,' 'Betsy Ross' or 'White Angel' ('Angel White') lilac. Lilacs need a neutral soil pH, close to 7.0. You will probably need to add lime at planting. Call your local Extension office (1-800-ASKUGA1)) and ask them how you should bring in soil for a soil test.
Q: At my new home the bermuda grass was mowed 3 inches high. The first time I cut it, I set my mower at 2.5 inches. The grass seemed to lose a lot of green. Your website says a good height for bermuda is 1-1.5 inches. But dropping from 3 to 1.5 inches doesn't seem like the right thing to do. Danny Womack, Rome
A: Your instincts are correct. If your question had come in spring, you could have gradually lowered your mower to the correct height. But now in fall, I'd mow it at a height that leaves some green showing until everything turns brown in November. Leave it alone until it's 50 percent green in April and mow it at 1.5 - 2 inches then. For regular maintenance, mow each time it reaches 2.5 inches
Q: We have noticed lots of caterpillars nesting in the sweetgum trees. Is it worth trying to control this infestation with insecticides or will they disappear by themselves? Lynn Bauer, Coweta County
A: I think you're seeing fall webworms. They build their protective webs in pecan, sweetgum and small maple trees. Their homebuilding activities started in June but the webs are just now becoming noticeable. Although they do not permanently harm trees, they are certainly unsightly. One simple control method is to pull the webs down with a long pole. Wasps, yellowjackets and hornets love to eat caterpillars and have been so far kept at bay by the diaphanous dwelling cover. You could also spray around and into the nest with organic caterpillar killers that contain Bacillus thuringiensis (B.t.)
Q: We've just moved into a new home with nice landscaping. We would like to redo the landscape but I don't want to clear-cut everything. Are there any companies that would come and harvest existing plants for their own use? Chris B., Peachtree Hills
A: Your heart is in the right place but I'm not sure any company would want your plants. A landscape company must guarantee the health of plants it installs. That would be hard to do with your plants compared to what they could buy at a nursery. One idea would be to contact a local garden club and ask if anyone would like to rescue plants in your landscape. Master Gardeners (1-800-ASKUGA1) might be interested. Another possibility is to advertise their availability at www.freecycle.com. Your plants definitely have value to someone. Don't let them go to waste!
Q: Is it OK to prune Knock Out roses in the fall? Janet Cork, Walton County
A: This is a fine time to tidy yours up. Remove empty sprays of flower buds, clip out long branches and remove any dead wood. Your plant won’t produce more flowers this year but it will be ready for any major pruning you do in February, and it will be attractive for the winter.
