Meet Jack Frost

I was introduced to Jack Frost in 1941, when I was 9 years old. The local park recreation department was rehearsing for its big winter production, and I was cast as Jack himself. I interpreted the role as a kind of gleeful Grinch, leaping around unsuspecting dancing flowers that would soon be turned to mush by my magic silver wand and a dusting of Ivory Snow soap flakes.

These rehearsals came to a permanent halt after Dec. 7, and we were suddenly at war. I was furious. I really wanted to kill those flowers.

This winter, Jack Frost made an extended appearance in late December. After four freezing nights, I walked around the garden and found only a couple of frost-damaged plants.

One was a new plant called Plectranthus, a member of the mint family. I hadn't done my homework on this plant. Before the frost, it had been blooming for two months, a sturdy plant with tough-looking basal growth topped with brilliant periwinkle-blue salvia-like flowers on upright stems. I was excited because I thought I'd found a great winter bloomer, but a second glance in Sunset's Western Garden Book indicated that Plectranthus is a container plant for climate zones 22 to 24 (our zone is 14), and that it is a tropical plant more at home in Hawaii.

After the first freezing night, the Plectranthus looked liked overcooked spinach. Oh, well. A few minutes of research would have saved this plant.

We live in a Mediterranean climate, a temperate zone with cold, rainy winters and hot, dry summers. But we have occasional spikes of extreme weather, so it is wise to know how to protect tender growth and which plants are susceptible to frost damage.

First, listen to weather forecasts and act on frost warnings. The outer leaves are the first parts of a plant that are affected. These need to be covered by a sheet or tarp held up by stakes so that the material doesn't actually touch the leaves.

Cover young citrus and new leafy plants. Strings of Christmas lights hung in the branches can also help deter damage. There is also a commercial spray that will coat tender leaves. Ask nursery employees for advice.

Bring container plants under the eaves or temporarily inside the home or garage.

Water all your plants when you know a frost is imminent. Dry freezing air will suck the moisture from a plant, starting with the leaves, then buds and stems, and finally the roots. Winter soil is usually warmer than the air above it, but a good watering will help the roots just as a moisturizer helps keep our skin from chafing.

Mulch around plants with three inches of aged manure or compost, keeping it away from the trunk or main stem.

Evergreen plants, in general, are not affected by frost as their leaves or needles are coated with a waxy material that protects them from harsh weather.

When we speak of a plant being hardy, we mean that it can tolerate temperatures below freezing, in some cases well below. Half hardy means plants are resistant to some cold but not prolonged freezes. Tender plants are not frost tolerant and may succumb to temperatures below freezing. Before buying a plant, read the labels and ask the nursery employees about its cold hardiness.

Many plants are now in a state of dormancy. They need to remain in this state to survive, so resist the urge to fertilize them. You don't want to promote growth now because another frost would destroy the new tender leaves and might kill the plant. Also resist the urge to cut back the ugly, frost-damaged foliage. It is protecting the plant from further damage. If you do cut it back, you are exposing the remaining vulnerable stems and leaves to the next frost.

Winter can be an exciting time in Napa Valley. One day can bring blustery storms, the next brilliant cold beauty. All kinds of birds arrive to glean seeds. Winter only lasts for a few short months, so don't let Jack Frost get you down. Remember, spring is sure to follow.

On Feb. 3, brighten your day by attending the annual camellia show at the Napa Senior Center, 1-5 p.m.

Master Gardeners are volunteers who help the University of California reach the gardening public with home gardening information. Napa County Master Gardeners (www.mastergardeners.org) are available to answer gardening questions in person or by phone, Monday, Wednesday and Friday, 9 a.m. to noon, at the UC Cooperative Extension office, 1710 Soscol Ave., Suite 4, Napa, 253-4221, or toll-free at 877-279-3065. E-mail your garden questions by following the guidelines on the Web site. Click on Napa, then on Have Garden Questions?