That 2 1/4” of the wet stuff that a couple weeks ago was most appreciated. Turned out to be more rain than I anticipated arriving slowly so as to sink in and really do some good. The ducks in Boulder Creek are happy again.
Who knows what our La Niña weather will be like this winter but we do know that some of our rain events will come with a vengeance. It’s not that unusual for our area to get 8 inches of rainfall during a storm and that can create havoc on an unprotected hillside. Fortunately, October is a good time to do something about it.
Fall is the perfect time to plant in our area. The soil is still warm encouraging root growth and the weather is mild. Using the right plants on hillsides can help slow and spread runoff and prevent soil erosion. Mulch also protects soil from direct rain impact and slows runoff across bare soils. Covering the steepest slopes with jute netting through which plants may be installed is an added precaution.
There are many attractive plants that work well for erosion control. Often they need to adapt to shallow, poor soil and cope with less than ideal conditions all while putting down dense, strong roots. California natives are well suited to this job.
Common native shrubs include ceanothus and manzanita of all types. Calycanthus or Spicebush has fragrant flowers in late spring blooming well into summer with a spicy fragrance. The foliage is aromatic when crushed and changes from a spring green color to pale golden in autumn. Decorative woody fruits last into winter making this shrub attractive year round. It thrives with infrequent to moderate watering. Combine with coffeeberry and deer grass in sunnier spots or with Douglas iris and giant chain fern in shaded spots below trees. All these plants have deep roots and control erosion.
Ribes sanguinem or Flowering Currant is another show stopper capable of controlling erosion. In the spring the long, flower clusters of this deciduous shrub will dominate your garden. Choose from white flowering ‘White Icicle’ or ”Barrie Coate” and ‘King Edward VII’ with spectacular deep red flower clusters. ‘Spring Showers’ has 8 inch long pink clusters. Grow in full sun to partial shade. This California native requires little water once established and is a valuable nectar source for hummingbirds.
Some other good California native shrubs for erosion control are western redbud, mountain mahogany, western mock orange, lemonade berry, toyon, matilija poppy and western elderberry. ribes viburnifolium, creeping mahonia and baccharis. Ceanothus maritimus, ‘Heart’s Desire’ and ‘Anchor Bay’ are all good ground cover selections and are not attractive to deer.
Symphoricarpos – Common Snowberry or Creeping Snowberry – can hold the soil on steep banks. This native tolerates poor soil, lower light and general neglect.
Smaller natives that put down deep roots are yarrow, coast aster, California fuchsia, wild grape, mimulus, buckwheat, wild rose, sage and salvia.
Bush poppy (dendromecon rigid) is another native found right here in our area and needs no irrigation at all once established. Beautiful bright yellow, poppy-like flowers cover the plant in spring. They can be propagated from cuttings taken in summer and are pest and disease free.
Low water-use non-native ground covers like cistus salviifolius, grevillea lanigera, rosemary prostratus, rubus pentalabous, correa and sarcococcas are also good low-water choices.
Remember when setting plants on a steep slope to arrange them in staggered rows. Make an individual terrace for each plant and create a basin or low spot behind each one – not around the stem – to catch water. Set the crowns of the plants high so they won’t become saturated and rot after watering and make sure mulch does not build up around the stem.