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Tuesday, Apr 24, 2018
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Weeds: Beauty Or The Beast?

For a foray into gardening hell, try hand-to-hand combat with a subterranean torpedo. It lies buried in your yard, quietly shooting green, grasslike blades up into your flower bed. You try to pull them up, but you just get the green stuff, never the root. Dig down, and you discover why: A thick, white root runner with a missile-shaped "head" and a body 4 feet long or more shooting horizontally through the soil. All along the runner, new blades of torpedo grass are locked and loaded, ready to launch. What the summer's afternoon deluges do for lawns and shrubs, they also do for weeds. Even as the hibiscus and firebush plump, spread and multiply, so do weeds. Some, such as common dayflower with its delicate blue flowers, are pretty enough to serve as ground cover. Others give flora a bad name. Eternal vigilance and mulch can keep the lawn from being overrun. Add mulch for the flower beds.
"Overall, as far as mowing, watering and fertilization, the one rule that seems to make sense across the board is consistency," says weed authority Philip Busey, associate professor of environmental horticulture at the University of Florida. Keeping the lawn healthy hides the soil from the sunlight, thwarting the germination of weed seeds just under the surface. But take care not to overfertilize. Too much nitrogen invites pests such as chinch bugs, which chew up the grass and create bare spots that, in turn, invite weeds. Fertilizing the lawn before grass is actively growing tends to increase the number of weeds, Busey says. Many varieties of weeds afflict Florida lawns, and different herbicides are used to zap different kinds. You have to be careful; those treatments will also kill the plants you want to keep. Read the label, including the fine print, Busey says. Follow the directions. A herbicide may declare on the label that it's effective on Southern grasses, yet a footnote may warn against using it on St. Augustine. If over-the-counter herbicides don't work, you may need to call a professional. Commercial companies have access to some herbicides that aren't available to the home gardener. What's growing besides grass in your yard? Take a close look and you'll probably find a garden of good and evil. Philip Morgan Crabgrass Lawns mowed too short tend to have crabgrass, Busey says. There's nothing on the market that kills it, so the recommended form of attack is pulling it up by hand. Busey has had some good results sprinkling baking soda on crabgrass, but you have to be careful it doesn't land on the good grass. He has noticed some resourceful souls selling "crabgrass killer" on the Internet. It's baking soda mixed with food coloring and maybe something to give it a different scent. Torpedo grass "If a lawn is heavily infested, you have no choice but to treat it chemically," says Busey. Glyphosate, which is in Roundup and other weed killers, is effective but requires repeated applications. Busey recommends spraying, waiting four to six weeks or until new growth is seen, then spraying again and waiting another four to six weeks to spray a third time. Spanish needle This pretty little flower isn't a problem unless it gets out of hand. Spanish needle tends to start growing at the edges of property, like next to a fence. It's characterized by starburst-style seedpods made up of small black needles that stick to your clothing. It thins out with regular mowing, Busey says. Creeping beggarweed Another dainty little flower, beggarweed has pink to rose-colored blooms and a large taproot with long runners. It's best recognized by its green segmented seedpods, which break apart and stick to your pant legs like Velcro after you've walked through a patch. If you want to get rid of this one, Busey suggests calling a professional. Yellow nutsedge Characterized by yellow flowers and soft, spikelike petals, it is a cousin to the equally common purple nutsedge. If you have just a few, pull them up by hand, Busey says. If there are more, try Basagran, Image or Roundup. Sandspur The nastiest version is the field sandspur, which can painfully pierce the flesh with its sharp, rigid spikes. "The best thing to do is take a shovel, dig it up, put it in a plastic bag and throw it away." Dollar weed This low-growing water guzzler loves over-irrigated St. Augustine lawns. Bahia lawns are less susceptible. SpeedZone St. Augustine formula and Trimec Southern will take it out. Florida pusley A creeping weed with tiny white flowers, pusley takes over thinning lawns. On the positive side, it makes a thin yard look full and green. Regular irrigation helps prevent the conditions that encourage it. To get rid of it, pull out small infestations by hand. Bigger problems call for an herbicide containing atrazine.

Reporter Philip Morgan can be reached at (813) 259-7609 or [email protected]

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