Winter in the Native Plant Garden
California native plants start a new growth cycle with the first soaking rain of fall. Leaf and flower buds form, roots proliferate and wildflower seeds germinate. Fall is actually “spring” for our native plants and winter is a time for quiet growth culminating in a burst of flowers and seeds in spring. Summer and early fall is typically the dormant time, though individual plants follow their own time-table, adding to the charm of growing native plants.
A garden’s elevation and its microclimates make a difference in the temperature, snow and frost that plants are exposed to. Most natives tolerate being covered with snow which acts as a blanket, but frozen soil and frozen roots can create problems. Fortunately, deeply frozen soil is not a problem in our Mediterranean climate, while nature provides enough chill for those plants that need a period of cold and for seeds that require cold stratification in order to germinate.
We can help our native garden in winter by observing a few simple guidelines:
- Avoid heavy mulch. Natural leaf litter under the plants may help protect them, but deep mulch will keep the soil too cool. Moist, bare soil that is uncultivated gathers warmth in the day and radiates it up into the plant at night. Expended top growth, such as the stems of California fuchsia, can be left in place and will help protect the plant.
- Open any basins that surround plants to prevent water from pooling on the roots. Native plants may suffer root rot in soggy, wet soil. Hopefully you avoided planting in depressed areas. The top of slopes and raised mounds provide the best drainage.
- Irrigate as needed if the first rain of the season is followed by warm weather. Moist soil holds more warmth than dry soil. Evergreens need moisture throughout winter because they continue to transpire.
- Avoid pruning in early winter to prevent tender new growth that may freeze. The time for pruning native plants is variable. For winter-deciduous plants, it is just before new growth begins in early spring. For others, refer to plant guides for the appropriate pruning time.
- Control weeds that sprout with the first rain. Learn to recognize immature wildflowers.
- Shake the branches of shrubs and trees that have leaves if there is a heavy snow. Broken branches are common when there is snow before deciduous leaves have fallen.
- Do not trim off frost damage until late spring when you are certain that the branch won’t resume growing. In late winter there may be a “false spring” followed by another freeze. Plants that started new growth are subject to freezing.
- Watch for plants to heave, especially your new plants. When there is alternate freezing and thawing of the ground, plants without strong root support may be pushed upward. You can add soil around the sides of the rootball, add light mulch or replant small plants.
- Protect from excessive deer damage. Yard fences or cages around individual plants are the most effective, while deer repellent sprays may work for a while. Planting aromatic plants nearby also may protect susceptible plants. Many native plants are ignored by deer or will grow with deer- browsing providing a natural pruning. Place upright rebar posts around the plant if bucks are using it to rub their antlers.
- Research a plant’s natural growing environment to find its best place on your property. Refer to books such as Growing California Native Plants for the Garden (Bornstein, Fross and O’Brien), Living Wild (Funk and Kaufman), Sunset Western Garden Book and Wildflowers of Nevada and Placer Counties (Redbud Chapter of the California Native Plant Society).
Even during the winter, you can enjoy your native plants by watching their subtle changes and learning their cycles. There is always something of interest to observe in the native garden.