Spot spray to kill weeds in winter

By Walter Reeves

For the AJC

Q: Since my centipede grass is dormant, can I spray Roundup on the broadleaf weeds that are doing quite well? — Drew Williams, Alpharetta

Enlarge photo

Walter Reeves/AJC Special Overwatering and overfertilizing are the main causes of fungus problems in lawns.

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A: Though your centipede grass lawn may look brown, that doesn’t mean the individual plants are dormant. I checked my neighbor’s centipede recently and, sure enough, I could find plenty of green growth below the dead stems that cover his lawn. If you apply glyphosate (Roundup, etc.) to your “dormant” lawn now, you will kill your grass. A better option is to spot spray with a broadleaf weed killer labeled for use on centipede grass, paying particular attention to the mixing rate. Because of the cold weather, you’ll begin to see weed control in two weeks.

Q: What is an appropriate product and application schedule for preventing fungus in my lawn for the coming year? Last year, brown patch was a particular problem. — Ron Mihelic

A: Lawn fungus problems are best addressed by correcting your lawn management practices, not by applying fungicides. Disease-ridden lawns are typically shady, have standing water, are irrigated and fertilized too frequently and are not mowed at the correct height. If you match your lawn grass species and maintenance practices to the site, disease problems will disappear. Get my lawn maintenance calendars at xrl.us
/lawncalendar.

Q: A friend wants to know how to repot their large staghorn fern.
— Tim Lewis, Elko

A: A staghorn fern is composed of several rounded brown shield fronds and even more green “staghorn” fronds. Before dividing a plant, soak it thoroughly for a day to make sure all roots are well-hydrated. A shield frond hides a mass of roots and rhizomes. Carefully lift an edge and insert a sharp knife to separate roots and fronds from the larger mass.

You’ll have more success dividing the original plant in half or thirds, without trying to separate each individual growing plant. Wrap the base of the separated pieces in wet sphagnum moss and tie each to a wide board with nylon fishing line. Given sufficient light and occasional watering, the new plants soon will begin growing once again.

Q: We are looking for aquaponics training or somebody who uses the system in Georgia. We have a 16-by-16-foot fenced area. — Anne Daniel

A: Aquaponics is the system of growing fish alongside edible plants, using water from the fish tank to fertilize the plants. Tilapia are usually the fish of choice, but catfish, crawfish and freshwater prawns also can be raised. It can be a fun experiment, but the need for daily attention may become more than you anticipate. You’ll need a greenhouse in which to keep the fish and plants warm in winter. David Epstein (www.earthsolutions.com) has installed several systems in Georgia. You can find practical notes at www.georgiaaquaponics
.com. Good luck and let me know how things turn out!

Listen to Walter Reeves from 6 to 10 Saturday mornings on WSB-AM (750). Visit his Web site, www.walterreeves.com, for detailed advice on Georgia gardening.