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Be a cold-weather friend to your plants

Jack Frost wasn't just nipping at your nose last week. A powerful front brought low temperatures that stayed long enough to freeze plants. And it wasn't pretty. • If you prepared for the cold, dry arctic blast by watering your sensitive plants and sheltering them with sheets, blankets, tarps or other coverings, you may have beat winter's frigid blast. But in areas where low temperatures dropped well below freezing for hours, the botanical carnage could appear grim. Temperatures are cooler again now and we'll see that pattern of warm to cold and back to warm probably into March. Here's what to do now. More tips, Page 4H

Triage the plants

In the aftermath of a freeze or hard frost, your woody plants may be looking haggard and their leaves are turning brown. But don't give up just yet. Experts caution against removing or severely pruning cold-damaged plants for at least several weeks. Give them time to bounce back. Watch for new growth in the spring, then prune branches back to the green tissue.

Soft herbaceous plants are another story. If yours were blasted by the freeze, they've probably collapsed into a pile of mush, which you should remove to prevent decay-related problems. Keep the roots in the ground, though, in case new growth emerges in the spring — often the case with banana plants, says Pinellas County horticulture agent Pam Brown.

Experts say most plant tissue freezes at 28 degrees, but some plants are less cold-hardy. In the vegetable garden, vegetable plants such as squash, tomato, eggplant and snap beans freeze at 30 degrees. If your veggies are mush, you'll find plenty of new starter plants at the local garden center.

Assess the grass

Frost-covered lawns might have delighted kids who could slide on its icy surface and even make frost angels, but if yours is St. Augustine, it's probably not so happy. The popular turf is cold-sensitive, and may start to look wilted with a white cast that eventually turns dark brown and smells putrid. Resist the urge to water it back to health; you won't, and you'll only waste water. Come spring, you'll know whether your lawn will bounce back or require repair.

You can test your turf for cold damage now using this approach from turfgrass experts at the University of Florida: Remove several 4- to 5-inch-diameter plugs of sod from the lawn, place them in a sunny, warm location such as a windowsill and watch for new growth. If you don't see healthy-looking new growth within 30 days, your lawn has probably sustained cold damage that will require repair.

Monitor palms

Palms, especially cold-sensitive ones such as the coconut, can be damaged by freezing temperatures that destroy tissue (which can't be regenerated) and weaken the plant. It's like having a weakened immune system; if a palm is lackluster, it's susceptible to attack by pests and disease, which ultimately leads to its demise.

You can remove cold-damaged fronds (never green ones) now and watch for new growth from the crown in the spring or summer. If the new fronds suddenly collapse, the palm is most likely unable to conduct water through its trunk — a result of freeze damage that's lethal. Researchers at the University of Florida suggest treating cold-sensitive palms with fungicidal copper spray to prevent the pathogens that can kill after a freeze. The remedy isn't proven, but you can get details on this approach at (search for cold-damaged palms).

Healthy plants are better equipped to survive the many curves nature throws their way — from pests and disease to droughts, hurricanes and winter's cold temperatures. The care you provide throughout the year, including watering, feeding, proper pruning and disease and pest control, is vitally important to helping your landscape weather it all. Even another visit from Jack Frost.

Brace for the cold

The risk of frost lasts until early March, so be prepared.

The day before freezing temperatures:

• Make sure all plants are well hydrated.

• Bring potted plants indoors or place them close to the house.

• Cover potted plants and cold-sensitive plants in the landscape with sheets or blankets and make sure they touch the ground to trap heat. If you use plastic, don't let it touch the plant. Plastic conducts cold onto the plant's surface. You can also use large trash cans or buckets overtop plants.

• Indoor/outdoor lights, such as a strand of large outdoor Christmas lights, can be placed under the covering to warm the space by about 3 degrees. Don't allow lights to touch the cover or plant, which could become a fire hazard.

• Turn off the automatic irrigation system so plants are not watered during the freeze.

• Empty birdbaths or other standing water features.

Immediately after the freeze:

• If plants are covered with frost, gently water them to melt the frost before the sun scorches tender foliage.

• Keep soil around plants moist but not soggy.

• If the soil in potted plants is frozen, add water to thaw.

Be a cold-weather friend to your plants 01/30/09 [Last modified: Thursday, February 5, 2009 9:36am]
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