Growing Cover Crops- Part I

Every drop of rain that hits bare soil is destructive. Over 3000 years ago the Chinese knew how to protect their soil from erosion and increase fertility by planting cover crops. Early Nile Valley inhabitants 3500 years ago also practiced this method of agriculture as did first century Romans. Lupines were planted in poor soil when no animal manure was to be had. I learned this and also how to protect and improve my soil from Orin Martin, manager of the Alan Chadwick Garden at a cover crop workshop recently on the campus.

aster_Michaelmas_daisy.2048“It’s all about the biology of the soil”, Martin said. “You grow the soil that helps you grow the plants”. A cover crop is really anything that covers the soil and protects it from rain, trapping nutrients and preventing them from leaching downward, he explained. Cover crops can increase the tilth of the soil. Quick germinating grasses easily loosen the top foot of soil with their root mass. Legumes have a tap root, a bio drill, that penetrates 30″ downward while alfalfa roots can grow even deeper.

Cover crops like bell beans, vetch and fava beans are especially valuable as they increase nitrogen levels in the soil in two ways. Atmospheric nitrogen can be “fixed” and left in the soil to fertilize subsequent crops. This is in addition to the nitrogen left from the foliage of the legume.

Cover crops are also called green manure when they are chopped up and turned into the soil in spring lettuces_after_cover_cropping.1024before going to seed. The planting of legumes like peas and beans can actually increase nutrients in your soil giving you a net gain which is needed to offset what you take out of the soil when you harvest fruits, vegetables and flowers.

From late September to the end of November is the best time to sow cover crops. You will need to irrigate lightly a couple times per week if it doesn’t rain. You can also wait to sow just before the rains start. Be careful about working overly wet soil however as you can ruin the structure of your soil.

The Chadwick Garden, Martin explained, originally was heavy red clay. 35 years of soil building with bell beans and vetch cover crops and compost have established a level of fertility that now supports several acres of vegetables, fruit trees, berries and beneficial flowering plants. Fall-sown, spring ploughed-down cover crops are the sole fertilizer used for the better part of the last decade.

Soil_builder_cover_crop_mix.1600Martin explained that recent research now recommends planting a tandem of grasses and legumes. Annual cereal grasses such as oats, rye and barley germinated quickly to hold and shield the soil until the legumes take hold. Bell beans, fava beans and vetch which are the best legumes for our area grow slowly the first 3 months then take off growing 70-80% in the last 3 months. The ratio of grass seed to legumes can vary from 10% to 30%.

There are other legumes that fix nitrogen but no where near as efficiently as bell beans.  Crimson clover seed is also more expensive, needs lots of water to sprout and competes poorly with weeds. Mustard causes competition with the fruit trees as bees will concentrate on the mustard flowers instead of the fruit tree flowers.

A question came up about using inoculants on legume seed. Martin explained that our soils have a native resident population of good bacteria that will break down the seed coat and encourage the plant roots to fix more nitrogen especially after cover cropping for a few years.

We all followed Martin out to the cover crop trial plots to see how the different types were growing. Bark chips will soon be applied to the paths. All of the gardens are mulched several times per year with wood chips. A 10 year study, Martin explained, demonstrated the amazing benefits of ramial chipped wood which is the type the tree service companies provide for free.

We watched him work the soil lightly with a metal bow rake then broadcast 8-10 seeds per square foot. Weeds were already cleared but Martin said this step doesn’t have to be perfect. Afterward the area was raked again lightly 1-2″ down and covered with 3-4″ of straw. Wood chips would be fine, too. Mulch heavier if you have bird competition. Cover crops are vigorous and will come up through just about anything, he said.  Water in lightly.

There are 3 ways to fertilize, Martin said. You can buy chemical fertilizer which is expensive and doesn’t do much for the soil. You can apply compost, which being carbon based, ramps up beneficial fungal organisms in the soil. Or you can cover crop or grow green manure which increases beneficial soil bacteria. Orin Martin has proof of the benefits of the last two methods.

California Native Plants for Erosion Control

ribes_sanguineum_King_EdwardVII.1024Getting caught out in the rain last month was a timely reminder that the rainy season will soon be upon us.The Farmer’s Almanac predicts our “winter will be much rainier and cooler than normal”. Weather bloggers online posting an impressive number of charts and figures predict “a general dry trend”. NOAA says we have an equal chance of precipitation totals going either way.

My favorite predictor, the Sandhill crane, started its annual migration to the San Joaquin Valley several weeks earlier this year. Over the years, the timing of the migration has been a good predictor of both wet and dry winters. This year the early migration predicts an early winter with plenty of rain and snow.

Who knows what the weather will actually bring 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″ of rainfall during a storm and you know what havoc that can create on an unprotected hillside. Yes, folks, I’m talking major erosion of your precious land. 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 lives up to its OLYMPUS DIGITAL CAMERAcommon name Spicebush. Fragrant flowers appear in late spring and continue to bloom well into summer with a spicy fragrance similar to a wine cellar. 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 it with coffeeberry and deer grass in sunnier spots or with Douglas iris and giant chain fern in shaded spots below trees. These also have deep roots and control erosion.

Ribes sanguinem (red 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. There are many selections of this plant 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 are 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. Ribes viburnifolium, creeping mahonia and snowberry, baccharis, ceanothus maritimus and Anchor Bay are good groundcover selections.

Smaller natives that put down deep roots are yarrow, coast aster, California fuchsia, wild grape, mimulus, buckwheat, wOLYMPUS DIGITAL CAMERAild 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.

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.

California Native Plants for Erosion Control

ribes_sanguineum_King_EdwardVII.1024Getting caught out in the rain last month was a timely reminder that the rainy season will soon be upon us.The Farmer’s Almanac predicts our “winter will be much rainier and cooler than normal”. Weather bloggers online posting an impressive number of charts and figures predict “a general dry trend”. NOAA says we have an equal chance of precipitation totals going either way.

My favorite predictor, the Sandhill crane, started its annual migration to the San Joaquin Valley several weeks earlier this year. Over the years, the timing of the migration has been a good predictor of both wet and dry winters. This year the early migration predicts an early winter with plenty of rain and snow.

Who knows what the weather will actually bring 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″ of rainfall during a storm and you know what havoc that can create on an unprotected hillside. Yes, folks, I’m talking major erosion of your precious land. 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 lives up to its OLYMPUS DIGITAL CAMERAcommon name Spicebush. Fragrant flowers appear in late spring and continue to bloom well into summer with a spicy fragrance similar to a wine cellar. 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 it with coffeeberry and deer grass in sunnier spots or with Douglas iris and giant chain fern in shaded spots below trees. These also have deep roots and control erosion.

Ribes sanguinem (red 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. There are many selections of this plant 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 are 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. Ribes viburnifolium, creeping mahonia and snowberry, baccharis, ceanothus maritimus and Anchor Bay are good groundcover selections.

Smaller natives that put down deep roots are yarrow, coast aster, California fuchsia, wild grape, mimulus, buckwheat, wOLYMPUS DIGITAL CAMERAild 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.

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.

Firesafe landscaping – Part II

I walk regularly in Henry Cowell State Park in Felton. I can’t imagine losing the majestic redwood forest I enjoy so much to a fire. Over the summer there were several arson caused fires in the park. Actually 10 separate fires have occurred in the same general area and along the San Lorenzo River over the past 6 months, some caused by campfire escapes and some by arson. All of them were caused by humans.

OLYMPUS DIGITAL CAMERAWe live in this beautiful area because of the natural scenery and wildlife. To lose any part of it to wildfire would be tragic. Whether a fire is caused by humans or natural causes such as lightning it’s all the same to our neighborhood, our homes, our pets, our lives.

We know that fire in some instances can be good for the land. After many years of fire exclusion an ecosystem that needs periodic fire to remain healthy becomes overcrowded and flammable fuels build up. The Forest Service manages prescribed fires to benefit natural resources and protect communities. However, as we build homes further into nature prescribed fires are not always possible. This is where mechanical treatment can benefit ecosystems and people.

Mechanical treatment include thinning of dense stands of trees or other fuels that make an area better able to withstand fire. Pruning loser branches, piling brush or creating fuel breaks encourage a more manageable fire should one occur.

Last week I talked about how to make the area closer to your home more firesafe. Here are some more OLYMPUS DIGITAL CAMERAtips.

In areas 30-70 ft. away from your house plants should be trimmed and thinned to create well-spaced groups and help prevent a fire in the wildland from spreading to your home.  Be cautious with slopes.  If you have a large lot, the fringe area should be inspected and maintained regularly to eliminate any build up of dry brush and litter.  This reduces the chance of surface as well as crown fires.

Plant arrangements, spacing and maintenance are often as important as plant types when considering fire safety. Group plants of similar heights and water requirements to create a landscape mosaic that can slow the spread of fire and use water most efficiently. Use plants that no not accumulate dead leaves or twigs. Keep your landscape healthy and clean. On a regular basis remove dead branches and brush, dry grass, dead leaves and pine needles from your yard, especially within 30 feet from your home and at least 150 ft if you’re on a hill. Keep trees spaced at least 10 feet apart with branches trimmed at least 10 ft away from your roof. It’s best, however, to keep trees further from your house. Low shrubs can be closer in and herbaceous perennials and groundcovers can be nearest the home.

Extremely flammable plants have a high content of oil or resin and should be separated from each other, removed of dead branches and lower limbs and kept free of dry debris anywhere around your property.  Extremely flammable pyrophytes like hollywood juniper, pines, fountain grass and Japanese honeysuckle will need a higher level of maintenance.  Other common plants that are highly flammable ares sagebrush, buckwheat and deer grass.  Rosemary and purple hopseed also fall into this category.These contain oils, resins and waxes that make them burn with a greater intensity.If you have these plants on your property yearly pruning and maintenance is important.

Irrigation is vital in a fire safe landscape to maintain plant moisture especially in the 30 ft around your home.  Choose the right irritation system. While all plants can eventually burn, healthy plants burn less quickly. Consider drip irrigation and micro sprays for watering most of your landscape. Use sprinklers for lawns and other groundcovers or turf. Even drought adapted species and natives will benefit from watering every month or so during the dry season. Unwatered landscapes generally increase the risk of fire.

Mulching around your plants will preserve this precious commodity in these times of drought.  Plantings beyond 30 ft. should be irrigated occasionally but to a lesser extent.  As you get 70-100 ft from the home, native plantings that require little or no irrigation should be used.

Using fire resistant plants that are strategically planted give firefighters a chance fighting a fire around your home especially within the 100 foot defensible zone. Each home or property is different and you will need to look at the unique qualities of yours in planning your firescaping. Some of the info for this column was obtained from 2 valuable booklets.   ‘Living with Fire in Santa Cruz County’, prepared by Cal Fire and available free from any fire dept or online and another from  Calif. Dept of Forestry at  www.fire.ca.gov/.

Firescaping-Part I

shaded_fuel_brake_sign.2048I drove through the Groveland area near Yosemite a couple of days before the Rim Fire started on August 17th. The local talk over Tioga Pass was then about the recent Aspen fire in the Sierra National Forest. The Rim fire has now burned 400 square miles of forest and cost $122 million to fight to date. What started as a 40 acre fire when discovered exploded to over 100,000 acres within 2 days. It is now the 3rd largest in California history.

Remote sensing satellite images indicate that virtually all the vegetation is dead on nearly 40% of the burned area. Chaparral and oaks will resprout but ecologist say it could take 30 to 50 years for the forest to reestablish itself. It scorched some of the last remaining old growth in the Stanislaus National Forest. Two years of drought and constant slow warming across the Sierra Nevada  worked to turn the Rim Fire into an inferno. For years forest ecologists shaded_fuel_brake_example.2048have warned that Western wildfires will only get worse. The fuels get drier and drier.

shaded_fuel_brake_example.2048There have been two wildfires close to where I live in Felton, one of which was only 5 miles away on Martin Grade in Bonny Doon several years ago. How can I protect my home? Is there a landscape that is safer in a wildfire than another? Which plants burn more readily?

Many people think they have to clear everything within 30 feet of their house to truly have a defensible space.  This is unnecessary and actually unacceptable due to soil erosion and habitat destruction reasons.  We want to retain the character of this beautiful area we live in, provide the food and shelter that our native wildlife are accustomed to but also reduce fire risk.  For example, grasslands mowed to leave 4-6″ of height allow insects, reptiles, amphibians, and small mammals shelter, food and a place to reproduce. Leaving 4-6″ standing also provides some erosion protection and shades out some of the weeds that follow disturbance.

Fire safe landscaping is a term used to describe defensible space.  It can look like a traditional landscape.  The idea is to surround the home with things less likely to burn and place them to provide separation between canopies and avoid creating fire ladders.  Highly flammable plants should be placed, whenever possible, with low-growing and/or low fuel plants.

Many homes may not have 30 ft. between their house and the property line but following these guidelines will help.  Plants in this area need to be the slowest to ignite and should produce the least amount of heat if they do burn.  There are plants with some fire resistance which include drought tolerant California natives and Mediterranean climate selections.  The key to fire resistance, though, is maintenance and keeping the moisture in the foliage high.

For example,  Baccharis pilularis or dwarf coyote brush is generally considered highly flammable if its lush green top growth covers a hazardous tangle of dry branches and leaves several feet high.  Trim this plant down low in early spring, remove the dry undergrowth, follow with a light feeding and watering and the new top growth is now resistant to fire.

Other considerations may be as important such as appearance, ability to hold the soil in place and wildlife habitat value. Some fire-resistant California friendly plants are western redbud, monkey flower, ceanothus, sage, yarrow, lavender, toyon, California fuchsia and wild strawberry. Also consider coffeeberry, flowering currant, bush anemone, snowberry, California wax myrtle and evergreen currant. Fire resistant plants from areas include rockrose, strawberry tree, Chinese pistache, barberry, escallonia, oleander, pittosporum, bush morning glory and wisteria to name just a few.

Next week I will discuss plant spacing arrangement and maintenance to help you prepare a fire-safe landscape around your home.