Controlling Erosion

All ceanothus are deep rooted and provide excellent erosion control.

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.

Calycanthus

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

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.

Planting California Natives in the Fall

In the California native plant garden at Gamble Garden this coral bells provides a beautiful focal point and the hummingbirds love it also.

When my optometrist was in Palo Alto I used to stop by Gamble Gardens on Waverly Street to see what was in bloom. Just down from Steve Jobs house, this historic garden dating back to 1908 is aa treasure. Over 300 volunteers keep the garden looking beautiful and it’s open to the public for free every day. The California native plant garden is one of my favorite areas. Fall is the perfect time to plant in your garden. Here are some ideas.

By planting from mid-September through mid-November, roots of all plants have a chance to grow during fall and most of the winter without having to supply nourishment to the leafy portion of the plant. Roots of deciduous plants still grow even after plants drop their foliage as long as the ground temperature is above 50 degrees. Cooler day and night temperatures slowly harden off the top of the plant to prepare for the cold days of winter.

Another reason that fall is the “no-fail” planting season is because plants put in the ground in fall need less water to establish. The plants themselves use less water since photosynthesis is slowed by shorter days even if it’s occasionally warm. Evaporation rates slow down also during fall so moisture in the soil lasts longer as well. Sometimes we get lucky with fall and winter rains perfectly spaced so the ground never completely dries out. Unfortunately this winter is predicted to be another La Nina but let’s hope we get more rain than last season.

Plants that thrive in dry, shady spots benefit especially from fall planting as they need established root systems before next years dry season. Dry shade sometimes occurs in places beyond the reach of the hose but also under native oaks. To protect the health of native oaks, it’s a requirement that plants underneath thrive with little or no summer irrigation.

King Edward VII Pink Flowering Currant

Plants of proven success under these conditions include native currants and gooseberry. Red flowering currant is a show stopper capable of controlling erosion. In the spring, the long, flower clusters of this deciduous shrub will dominate your garden. There are many selections to choose from so if the huge white flowers appeal to you ‘White Icicle’ will be beautiful in your landscape. ‘Barrie Coate’ and ‘King Edward VII’ have spectacular deep red flower clusters and ‘’Spring Showers’’ has 8″ long pink ones. 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, snowberry, matilija poppy and western elderberry. Rbes viburnifolium, creeping mahonia, snowberry, ceanothus maritimus and ‘Anchor Bay’s are good groundcover selections.

Pacific Coast Iris ( iris douglasiana )

Smaller natives that put down deep roots are heuchera, iris dougasiana, native grasses, yarrow, coast aster, California fuchsia, wild grape, mimulus, buckwheat, wild rose, sage and salvia.

Bush Poppy

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.

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.

The Power of Nature

Although not a mangrove or salt marsh, this Ginkgo, one of the oldest living tree species in the world, does its best to absorb CO2 from the environment.

We live close to some outstanding research facilities. NASA Ames Research Center in Mountain View had a role in the development of the Webb telescope that launched earlier this year. Stanford University is on the cutting edge of many medical advancements. Lawrence Berkeley and Lawrence Livermore National Laboratories are front and center of many studies that affect our daily lives.

When I was a kid my father used to work at the Lawrence Berkeley Lab. As a welder during the 1950’s I remember him telling me about working on the Bevatron which was the state of the art particle accelerator being built there. The goal of Berkeley Lab has always been to bring science solutions to the world.

Their newsletter, now published online, reported the results several years ago of a study about the increased rate that the earth’s vegetation is absorbing human-induced CO2. Never underestimate the power of nature – especially that of plants.

A new study published in this month’s Berkeley Lab newsletter, has found that plants, especially sea grasses, mangroves and salt marshes, are grabbing more carbon from the air than in previous decades. The study is based on extensive ground and atmospheric observations, satellite measurements of vegetation and computer modeling. They are even better than forests and can continue to do so for millions of years. The carbon found in coastal soil is often thousands of years old.

“To be clear, human activity continues to emit increasing amounts of carbon”, the study explains but plants have slowed the rate of increase in the atmosphere by absorbing more. “It’s a kind of snowball effect: as the carbon levels rise in the atmosphere, photosynthesis activity flourishes and plant take in more carbon, sparking more plant growth, more photosynthesis and more carbon uptake.”

Another player was identified in the study. Plant respiration, a process in which plants use oxygen and produce CO2, did not increase as quickly as photosynthesis in recent years. This is because plant respiration is sensitive to temperature. The study showed that between 2002 and 2014, plants took in more CO2 through photosynthesis but did not “exhale’ more CO2 into the atmosphere through respiration.

What does this all mean? “This highlights the need to identify and protect ecosystems where the carbon sink is growing rapidly,” says Trevor Keenan, a research scientist and author of the paper. “Unfortunately, this increase in the carbon sink is nowhere near enough to stop climate change. We don’t know where the carbon sink is increasing the most, how long this increase will last, or what it means for the future of Earth’s climate.”

Still I’m hopeful that the earth will heal itself if given the chance and we can thank plants including the humble houseplant for helping offset increasing levels of CO2 from fossil fuel emissions.

Berkeley Lab is at the forefront of research in the world of science. They continue to share information about how plants transport water from their roots up through the stem and how they respond to stress such as drought. The new data will provide insight about how to better tend crops and other plants under stress and to improved understanding and forecasting for drought-related die-offs of trees and other plant species.

Several years ago during the Ebola outbreak, Berkeley Lab was one of the research facilities searching for a cure. Rather than using human or lab animals, a crystal isolated from the cells of a broccoli related plant called mouse-ear cress, provided the target related protein. Researchers have used this plant as a model species for studying cell activities and genetics since the mid-1940’s and in 2000 this plant’s genome was the very first plant genome to be sequenced. Quite an honor for another humble plant.

The current Department of Energy Lawrence Berkeley Lab newsletter reported that the site of the former Bevatron, that operated from 1954 to 1993, has been designated a historic site by the American Physical Society for its exemplary contributions to physics. Dad would be proud to have been a part at its inception.

The current issue of the newsletter features a study conducted along with Michigan State University and the University of Southern Bohemia (yes, that’s a real place) about microbial photosynthesis. According to the article this info could help researchers remediate harmful algal blooms and develop artificial photosynthesis systems for renewable energy among other awesome applications. Check out the Berkeley lab newsletter online if you’re into browsing the internet like me. https://newscenter.lbl.gov/