Gardeners, Get Ready for First Fall Frost

SAVANNAH, Ga. (Sept. 25, 2008) – The dreaded first frost of fall looms just around the corner for many gardeners across the country. During a light frost, some plants may be killed, with little destructive effect on hardier vegetation.

Frost occurs when temperatures are 32 degrees or lower, wind is calm and cool air results in dew on lawns. While the first two conditions can readily occur both day and night, it’s difficult for dew to form during the day because of the sun’s heat.

At night (especially under a clear sky) temperatures can fall to a dew point. If temperatures fall below 32 degrees, frost will form. Dew and frost usually occur after several hours of darkness. Here’s a temperature guide from the Farmers’ Almanac experts to help you protect your gardens and plants:

• Light freeze: 29 to 32 degrees – tender plants may be lost, with little destructive effect on hardier vegetation
• Moderate freeze: 25 to 28 degrees – widely destructive effect on most vegetation, with heavy damage to fruit blossoms and tender and semi-hardy plants
• Severe freeze: 24 degrees and colder — damage to most plants

Farmer’s Almanac, the original sustainable living guide, recommends gardeners take the following steps to prepare their garden for the first fall frost:

• Protect cold-sensitive plants by covering them with old sheets, blankets, plastic bags or “hats” made of old newspaper. Cover when the sun goes down and uncover in the morning.
• Plant asters, hardy mums and ornamental cabbages that will bloom well after the first frost. Or plant new varieties like “Icicle pansies” and “Icicle violas” that will bloom until the snow flies and again in early spring, often before spring bulbs. Bred for cold climates, these tough new breeds are guaranteed to survive the harshest winters.
• Move houseplants indoors before the first frost. Abrupt changes in environment can shock plants, so it’s important to make the transition gradually. Begin by leaving the potted plants outdoors, but move them out of direct sunlight for about a week. After that, bring the plants inside for only a few hours each day for another week or so before bringing them indoors for good.
• Plan to transplant outdoor herbs a few weeks before the first frost. Chives, garlic chives, thyme, mint, winter savory, and lavender are especially suited to indoor conditions. Gently dig herbs out of the soil, taking care to cause as little root damage as possible. Select only the healthiest looking plants. Repot herbs in a mixture of equal parts fresh, high-quality commercial potting soil, sand and peat moss. Most herbs need 14 to 16 hours of daylight, including at least six hours of direct sunlight. If necessary, supplement daylight with fluorescent lighting during the short days of winter and late fall.

Check average frost dates in your area at http://www.farmersalmanac.com/weather/a/average_frost_dates. For more information from the weather experts at Farmers’ Almanac, visit www.FarmersAlmanac.com.