Winter is an excellent time of the year to add new shrubs, trees and perennials in your native garden.
If it has rained heavily wait until the soil has dried a bit before you plant, dig or walk in your garden. Working wet soil leads to compaction and compromises soil structure. Remember to water you chaparral and scrub plants if rainfall is light and the soil is very dry. Do not allow newly germinated wildflower seeds to dry out.
Improper watering is one of the biggest reasons for plant failure. In fact, overwatering, especially while native plants are not actively growing during the hot summer months, is a major problem. On the other hand, we often forget that many California native plants do most of their growing during the cooler, damper winter weather. A slight misting or a little drizzle will not provide enough water. This is especially true for young, unestablished plants, but even mature plants benefit from infrequent, deep watering during dry winters. If we do not get a good soaking rain for more than a couple of weeks, you may need to provide supplemental irrigation.
After planting natives during the winter season - the best time to plant in Southern California - it is important to water your new plants thoroughly to make sure that they settle in and their roots are completely wet. Through the first season your plants should not be allowed to dry out totally. Water well and then allow them to dry partially. If the plant is drooping and the soil is dry be sure to water immediately.
The roots of plants absorb water in the form of vapor from pockets in the soil. For this reason it is best for the soil to be watered thoroughly and then allowed to dry. A thorough watering ensures that the entire root ball receives water. Allowing the soil to dry creates good conditions for the absorption of water by the root hairs, and it reduces the likelihood of root rots from soil pathogens.
Get to know your plants and your garden conditions by checking your garden often. Dig down a few inches and feel the soil to determine whether your plants need water. Observe your plants so that you can tell when they are thirsty before they become too stressed. Gardening is not a passive sport, you must get down and dirty to be successful!
When winter rains fail to materialize, drag out the hose and give your plants a good soaking. Many California native plants are adapted to our dry, hot summers and typically cool, wet winters. Although established native plants will usually make it through these dry years, those that have been in your garden for less than three rainy seasons, may need help. Until mother nature cooperates, be sure to water approximately once a week. You may need to water more often if you have well-drained soil, new plants and the humidity remains low. Those of you with heavier soils, especially if there is mulch in your garden, may get away with less frequent watering. The only way to know is to check to see if the soil is damp a few inches down and to watch your plants. If the soil is dry and the plants are drooping, be sure to water. Extended drought will prevent new plants from developing the strong root systems needed to get through the summer months.
Winter is a good time to prune and tidy native vines.
Most vines benefit from a good trim this time of year. Vines can offer solutions to difficult landscape problems. They can be used to obscure chainlink fences or cinderblock walls. They can also be trained to grow over trellises, quickly providing privacy screens in narrow spaces. Native vines include desert, wild and cultivar grape, (Vitis girdiana, V. californica, V. ‘Roger’s Red’), clematis (Clematis lasiantha, C. ligusticifolia), California morning glory (Calystegia macrostegia), heart-leaf penstemon (Keckiella cordifolia), honeysuckle (Lonicera spp.), and others.
Most California fuchsia (Epilobium or Zauschneria) have finished blooming and are about to start their winter growth period. With cooler, wetter, winter weather (a bit of a tongue twister), other plants, such as the sages (Salvia) and bush sunflowers (Encelia californica) are also ready to start growing again. This is a good time to cut back many of these, but be aware that this horticultural practice is not appropriate for all native plants. Some do not appreciate a hard pruning, and others, like the warm season grasses, do not put on new growth in the winter. Many flowering shrubs, like the California lilac (Ceanothus) should be pruned in the spring after they finish blooming.
Sow wildflower seeds of poppies, phacelias, gilias, baby-blue eyes and tidy tips to brightened up your yard. Add sunflowers, madias and clarkias to extend the wildflower season into the late spring and summer.
Other Winter Gardening Chores
Plant your shrubs, trees and perennials during the winter for the best results.
It is a good time to weed your garden. Stay on top of the task so that you remove the weeds before they spread new seed.
Although there is debate about the desirability of mulch in native gardens, I find that for most plants it is helpful. Scrub, chaparral and desert plants prefer inorganic mulch, such as pebbles, decomposed granite, or gravel. Woodland plants do well with organic mulch. Keep the mulch away from the stems of the plants where it can contribute to fungal diseases.
Prune and pinch
For salvias, monkeyflowers and other new plants that are putting on rapid new growth, pinch back the tips to encourage bushier plants. Do not prune or pinch Ceanothus or you will reduce this year’s flowering, rather wait until after they bloom.
Aphids love succulent, new growth on plants. Salvias are especially susceptible to aphids. Hose down your plants to wash off many of these insects. Trim and remove the heavily infested tips, both encouraging denser growth and removing the aphids. Once the hotter weather arrives and the stems harden off, the aphids diminish and are not usually a serious problem.
Come stroll through the Garden to see manzanitas (Arctostaphylos species), California lilacs (Ceanothus species), currants and gooseberries (Ribes species) in bloom. From now until late spring the floral display is building by the day.
For more information on when to prune, consult Care and Maintenance of Southern California Native Plant Gardens by Bart O'Brien, Betsey Landis and Ellen Mackey (available for sale in RSABG's California Garden Gift Shop).