Q: Something is eating my hibiscus; the leaves are spider web-looking and then they are gone, nothing left but the veins. — Sandra Waldrip, email
A: It's likely the leaves are being consumed by hibiscus sawfly larvae. The adult insect looks like a housefly. She lays eggs on the underside of hibiscus leaves in early April. The eggs hatch into caterpillar-like larvae that damage the leaves like you describe. Insecticidal soap or any garden insecticide will kill them if you can direct the spray under the leaves.
Q: We were in Munich in April and were greeted by thousands of blooming chestnut trees. They looked exactly like the horsechestnut trees I remember from New York. What is preventing these trees from flourishing in the USA? — Steve Rino, email
A: The trees you saw were probably sweet chestnut, Castanea sativa. American chestnut, of which few remain, is Castanea dentata. My guess is that summer heat and perhaps chestnut blight serve to limit sweet chestnut survival in Georgia. Order one online and tell me how it grows after you plant it.
Q: I have been charged with finding a landscape maintenance company for our subdivision's common areas. Can you help with my endeavor? — Teresa Rose, Forsyth County
A: The Georgia Urban Ag Council is an organization of landscape professionals that meets regularly to hear topical speakers and share information about the landscaping business. They provide an online list of members who specialize in different aspects of landscape work for both homeowners and commercial properties. Go to www.georgialandscapepro.com and click on the "Find a Professional" link.
Q: Can I use wet, moldy hay for mulch in my vegetable garden? What about pine straw? — Matt in Madison
A: I think both materials could be used. I'd break up the moldy hay and spread it a few inches from the stems of vegetable plants. Contrary to rumor, pine straw does not acidify the soil but could make an acceptable mulch for vegetables, too.
Q: I think I did a bad thing. I spread corn gluten meal all over my veggie garden to help control weeds and give the soil a boost. Can I now plant other seeds in this garden or will the gluten kill them, too? — Melissa Soucy, email
A: In my experience, corn gluten meal gives poor weed control under Southern conditions. Till the area where you want to plant, incorporating the corn gluten meal into the soil. I predict your seeded vegetables will grow fine.
Q: I have a koi pond. I replace about 10 percent of the water weekly. Can this water be used safely on lawns? — R. Chaffer, email
A: Your lawn will love it! Lots of gardeners have experimented with aquaponic systems where "fish water" is used to fertilize vegetables. I foresee no problems using the pond water on your lawn.
