McCreary: How did your garden survive the freeze?

<p>The question of the month seems to be “How did your garden survive the freeze?” In the first days after December's cold snap, most gardens showed some damage, but as the weeks have passed, more and more plants are looking sad.</p><p>If there is any upside to cold damage in our gardens, freezing weather allows us to identify microclimates that we might not know we have. In my own garden, for example, identical plants in different locations, equally well established, fared completely opposite because of the way cold air either collected around them or flowed away.</p><p>While it's tempting to clean up all the damage when a nice day rolls around, dead stems on many plants offer some protection to buds at the base and roots below ground. Species such as Mexican sage (Salvia leucantha), whose 3-foot stems were filled with purplish velvety wands last fall, could be cut back now by about half for appearance's sake, but wait until the base is covered with several inches of new growth before completely removing old stems. </p><p>Use the same approach for agastache and other perennials, such as bat-faced cuphea (Cuphea llavea). Tall stems are dead but new growth is beginning to show at ground level.</p><p>Some species, such as fuchsias, shouldn't be touched at all until warm days are here to stay. Even though cold-damaged twigs look unsightly, don't remove them. They offer considerable protection to living wood and roots. After all danger of frost is past, prune to shape — severely to hold down size of plants in the ground, lightly to stimulate more growth. </p><p>Lantana should be handled similarly. In warmer microclimates, lantana remains evergreen during winter, but in colder locations, it can be severely damaged by frost and freezing. Wait until growth resumes in spring before trimming back stems. Drastic pruning that cuts stems close to the base produces denser growth whereas light pruning results in stems becoming tangled and unsightly.</p><p>Drastic cuts</p><p><MC>Some shrubs benefit from drastic pruning every few years or more often when they begin to look scraggly. Stems and foliage die back in the bottom half as vibrant foliage gives way to twiggy growth and blossoming wanes. In such a case, it pays to renew the entire shrub by pruning all stems to soil level or a few inches above.</p><p>New growth begins quickly and the result is a brand new plant. Some gardeners are reluctant to take on such a heavy hand, however, knowing that a radical treatment means it will be several months before the shrub regains its original size.</p><p>Abutilon<MC> (flowering maple). Many gardeners like to cut all stems to the ground every year or two in early spring to promote dense growth, but others like to prune back to a bud low on a stem or do nothing at all.</p><p><MC>Buddleia<MC> (butterfly bush). The best way to control the size and appearance is to cut back all growth to about 6 inches from the ground in early spring. Left unpruned, some species will reach 15 feet high and wide.</p><p><MC>Garrya<MC> (silktassel). Little or no pruning is needed when grown in a hedge row or as a specimen plant. Any trimming should be done after beautiful cream colored catkins up to 12 inches long lose their dazzling glow. Later pruning removes next year's flowering.</p><p><MC>Hydrangea.<MC> Pruning mophead or bigleaf (H. macrophylla) during dormancy removes buds that formed last summer and are ready to bloom. But if you haven't thinned out old, dead, crowded, or crossing branches for a very long time, don't delay; do that now. After bloom, shorten stems leaving two to four pairs of buds per stem. For peegee hydrangeas (H. paniculata), prune plants back halfway. To renew completely, cut all stems low to the ground.</p><p><MC>Hypericum<MC> (St. John's wort). Low groundcovers can be mowed or shortened with a string trimmer. Medium and large shrubs respond with lush new growth when pruned 4 to 6 inches to the ground.</p><p><MC>Mahonia.<MC> No pruning is needed unless plants become too leggy and unattractive; then, cut to the ground.</p><p><MC>Nandina<MC> (Heavenly bamboo). When plants lose lower foliage, remove stems to ground level, a few at a time. Nandina becomes an odd looking plant when stems are cut at higher points. It's possible to maintain a cluster of stems at 3 feet by removing the tallest ones every year or so. </p><p><MC>Sambucus<MC> (Elderberry). Grown as a screen or hedge plants, sambucus needs little attention, but in a prominent position, cut it to the ground annually in spring to achieve a more pleasing profile.</p><p><MC>Santolina<MC> (Lavender cotton). Annual trimming is advised but for plants that grow rampantly, cut to about 6 inches from the ground every other year, always leaving ample buds.</p><p>Rosemary McCreary, a Sonoma County gardener, gardening teacher and author, writes the weekly Homegrown column for The Press Democrat. Write to her at P.O. Box 910, Santa Rosa, 95402; or send fax to 664-9476.</p>