Q: I put zinnias around my mailbox. They grew five feet high! Is there a way to cut them back so they won’ t get too tall? Joyce Thomas, email
A: On a garden tour in England, I learned the phrase “the Chelsea chop.” British gardeners have learned that they should cut back perennials and tall-growing annuals around the time of the annual Chelsea Flower Show in late May. When they do so the plants sprout new stems, grow stockier, and have more flowers than they would otherwise. When your zinnias are six inches tall, pinch off the growing tip with a thumbnail. The plant will produce two stems at that site. Each stem can be pinched again when they’re six inches long. At this point, add fertilizer and let the plant grow and flower. You’ll have a stocky plant with lots of blooms to enjoy.
Q: I believe I have a fusarium infection in my garden soil. Plants start out healthy but quickly wilt and discolor. Is soil solarization an option? Allen LaBerteaux, Gwinnett County
A: Fusarium is a root disease that is hard to eliminate from soil. Solarizing (covering the soil with clear plastic for two months and letting the sun heat it) might be useful sometimes but it means your garden is taken out of action all summer. In my experience fusarium is a disease associated with soil that stays moist too long. If this is true in your case, this winter consider tilling in an inch-thick layer of very gritty sand to a depth of 10 inches.
Q: I have an old silver maple in my yard that is losing bark and has dead limbs. How can I save this beautiful tree? Barry Brantley, Stone Mountain
A: My answer will disappoint you, but I think you should have it taken down. Silver maple is prone to many problems. It gets leaf spots and cankers and root diseases at the drop of a hat. The limbs are brittle so they fall easily. The leaves have little color in autumn, and they drop throughout the year, making a mess in a landscape. Major bark loss is almost certainly unstoppable. If the tree has any chance of falling on something valuable, like your house, your car, or you, this is a liability you don’t want to have.
Q: I have a large and beautiful bermuda lawn. I typically scalp it in spring. Can I get away with not scalping? It’s a pretty daunting job at my age. Doug Hines, Villa Rica
A: Plenty of bermudagrass lawns go without scalping in spring and look fine. The only advantage to scalping is that the soil warms more rapidly and the lawn turns green a little earlier in spring. You can start mowing when the lawn is more than 90 percent green, no scalping necessary.
Q: The builder planted a maple in the yard of my new house. I love bald cypress but they get huge. Is there anything else you can suggest? Greg Anderson, Loganville
A: There are smaller varieties of bald cypress that don’t grow so tall. Ask around for ‘Peve Minaret’ (20 feet high and 8 feet wide) and ‘Skyward’ (25 feet high and 10 feet wide).
Listen to Walter Reeves Saturday mornings on News 95.5 FM and AM750 WSB. Visit his website, www.walterreeves.com, follow him on Twitter @walterreeves, on Pinterest, or join his Facebook Fan Page at bit.ly/georgiagardener for more garden tips.