By Sharon Gibbons
Martha Berthelsen, The Watershed Project Program Manager, reflects on preparing gardens for the rainy season, capturing rainfall for our landscapes, and keeping debris out of our storm-drains!
In October and November, we fortunate Bay Area residents get to enjoy the start of the rainy season along with our cooler days and vivid fall colors of golds and bright reds of maple trees and Toyon berries. Instead of the traditional four seasons, according to author Glen Schneider, we have three seasons in California: the rainy season, the wildflower season and the dry season, each about four months long. The fall rainy season is our time to do fall planting and to design ways to retain rainfall in our landscapes and out of the storm drain.
Redirect your downspout
“A lot of people don’t realize that not only do chemicals wash off of streets that have a negative impact on our creeks when it rains, but the increased volume of runoff from all of our impervious surfaces has a very damaging effect by eroding the creek banks and washing out the invertebrates that form the basis of the food chain in the creek,” says Martha Berthelsen, Program Manager. We can design our landscape to slow, absorb, and filter rainfall to prevent it from rushing down the storm drain and harming our watershed. A diffuse source of rain sheeting off a driveway or patio might be best captured by a swale to slow, filter, and absorb the water. A single runoff source such as a downspout from a roof can direct runoff into a rain garden. Both features sink water into the soil, where it replenishes groundwater. Rain catchment systems, such as rain barrels, can also collect runoff from roofs to water the garden during dry periods.
Planting natives for pollinators and more
The fall season is the time to plant native plants in our gardens and in rain gardens and bioswales. The soil softens with rain, but is still warm and encourages root growth. Our native plants are often drought tolerant and hardy, adapted to California’s three seasons. By planting natives, we help to restore ecological connections evolved over thousands of years and which provide natural habitat for beneficial insects, pollinators, and wildlife. Having native plants in our garden helps give us a sense of place. “Planting native plants restores an awareness of our local ecological communities that encompass plants and animals, with humans being part of it too,” says Martha. “I really enjoy being in my garden or going out to our regional parks to see plants in their different phases, colors, and seasons and still recognize them as old friends. This really contributes to that sense of place,” describes Martha.
Give your soil a blanket
Protect your soil from erosion and compaction by heavy rains and wind by sheet mulching with overlapping pieces of cardboard and a thick layer of mulch. Mulch will also help to retain moisture and to repel all the weeds that sprout with rain. A thin layer of compost under the mulch will also enrich the soil, and prepare it for spring plantings of vegetables or ornamentals (most native plants don’t need enriched soil).
Adopt your local storm drain
As part of fall preparations, seek out your local storm drain and adopt it! You and your family can watch your storm drain on rainy days and clear out any litter and trash that washes down the street and catches in the storm drain. You can help prevent litter from washing into our creeks and the Bay, while preventing street flooding.
Everyone is welcome to join us for fall planting and to learn about rain gardens and bioswales at upcoming events this month.
Sign up now for Martha Berthelsen’s upcoming class: Wildlife and Watershed Restoration Gardening at Merritt College for spring semester starting in January 2017. Planning and implementing a garden or restoration landscape with native plants to create a refuge habitat for wildlife, and protect water quality in creeks and the San Francisco Bay will be covered in the class with many hands-on activities and projects.
Schneider, G. (2004) East Bay Municipal Utility District. Plants and Landscapes for Summer-Dry Climates (Nora Harlow, Ed.) Oakland, CA: Graphic Press.
Photo Credit: Kat Sawyer
