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beneficial insects, composting, cover crops, edibles, fertilizing, gardening tips, green manure, mulching, organic fertilizers, organic gardening, organic weed contol, sustainable gardening, vegetables

Growing Cover Crops- Part I

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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.

IPM, Napa wineries, soil, sustainable gardening

Growing Wine Grapes

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Napa_Valley_vineyard.2048Prune orchards once reigned supreme in the Napa Valley. Pears, walnuts and fodder for grazing sheep were also grown where now 45,000 acres of premium wine grapes flourish. The crush is on in Napa County.  Mostly cabernet sauvignon, chardonnay and merlot are being harvested at night but back in 1928 the prune crop was worth twice as much as wine grapes.

We all have an insect or two that we have to deal with in our gardens.  I found out on a recent excursion to Napa Valley that all those acres of grape vines could possibly be lost if the European grape moth has its way. Believed to have been imported in vegetables from Europe it was first detected in Napa County in 2009. Back in 2011 Santa Cruz County was dealing with the same pest. With quarantine efforts and eradication of fruits and flowers near the area where they were first detected our county hasn't had much of a problem with them since.

Integrated pest management is the ecologically sound approach to pest control. In Napa County, I learned that the European grape moth is being well controlled in recent years by organic sprays such as spinosad and BT. Another very effective control method used is mating disruption with pheromones.

These techniques might not be as picturesque as planting roses around a grape orchard as an early cabernet_sauvignon_grapes.2048warning system for fungal diseases but they have worked for the grape moth. Roses are traditionally planted at the perimeter of vineyards as both they and grape vines are prone to powdery mildew and Downy mildew in our Mediterranean type climate. If powdery mildew appears on the roses, the vineyard can be sprayed with sulfur. Although sulfur does not cure powdery mildew, it will prevent it.

Downy mildew is another deadly mildew that attacks the green parts of the grape vine. Once Downy mildew is detected on the rose bushes, the grape vines can be immediately sprayed with a solution of copper sulphate and lime.

Many of the vineyards also plant lavender and rosemary to repel many harmful insects, provide habitat for beneficial insects preying on undesirable insects and add a pleasant flavor to the wine.

cabernet_grapes_ready_for_crush.2048Sitting outside on a tasting room patio planted with beautiful flowering shrubs and perennials it's hard to imagine the delicious wine in your glass doesn't come effortlessly on the part of the winery. Like our area that grows pinot noir grapes exceptionally well, the terroir of the Napa valley is expressed in the flavor of its wine. The qualities of the soil, geography and climate all contribute.

A vast array of soils of volcanic and marine origin coexist in Napa Valley. Half of the world's soil orders occur here with more than 100 soil variations all affecting the character of the grapes. Soils guide the grape grower as to which rootstock and grape varieties to plant.  Valley floor soils tend to be deeper and more fertile and produce vigorous growth so the crop must be tightly managed to produce concentrated grapes. On the hillsides the vine has to struggle to survive the spare, rocky soils and naturally sets a smaller crop, producing smaller grapes of highly concentrated color and flavors.

Walking among the vines, I noted drip irrigation in use. I found out that traditionally Old World wine regions consider natural rainfall the only source of water that will still allow the vineyard to maintain its terroir characteristics. Spain has recently loosened the regulations of the European Union Wine Laws and France has been reviewing the issue.

Grapes depend on a certain amount of water mainly in the spring and summer and so here in California as well as other summer dry regions of the world like Australia, the vines are irrigated starting in May or June. It's a fine line to determine how much and how often to irrigate to preserve the flavor of the grape and not just grow lush plants with high yields.

In our own gardens we can train a plant to put down deep roots decreasing the amount of watering it needs. So it is in grape growing where the vine receives sufficient water during budding and flowering but irrigation is then scaled back during the ripening period so that the vine funnels more of its limited resources into developing grape clusters.

I enjoyed the gardens of the Napa Valley as much as the wine tasting. White Japanese anemone, pink sasanqua camellia and oakleaf hydrangea are all blooming. The dogwood trees are budded for next year's show and the Japanese maples are starting to color.

It's interesting to know that one grape vine produces about 4-6 bottles of wine per year and in 1968 the nation's first Agriculture Preserve was established to protect open space and prevent future over development.

 

beneficial insects, berries, California Native Plants, landscape design, perennials, wildlife gardening

The Sloughs of Watsonville

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sambucus_nigra_berriesEach year I wait for them in my garden and so do the robins, varied thrush, jays, spotted towhees, grosbeaks and band-tailed pigeons. The fruit of sambucus mexicana, a California native plant, is relished by an incredible number of songbirds.  The creamy flower clusters in the spring are a favorite of bees and other beneficial insects. My Western Elderberry grows tall and gangly in the shade of a California bay tree, shorter and more compact in the sun. Their exuberance for life makes me happy just to watch them provide for so many other species.

We've all driven down Hwy 1 past the strawberry fields and seen the wetlands at high tide as their many fingers reach far up into the Watsonville area. At low tide the Harkins Slough is visible off to the west, grasses blowing gently in the wind. Struve Slough passes under Hwy 1 also but most of it is hidden. The Watsonville sloughs wind around farms, fields and low hills not visible from the highway.

California has lost over 90 percent of its wetlands and the Watsonville Sloughs are one of the largest remaining freshwater marshlands in the state's coastal zone. It provides a crucial resting place for many specie of migrating birds. This area covers about 800 acres adjacent to the city of Watsonville. The slough system has 6 interlinked freshwater sloughs fed by the waters of the Pajaro Valley watershed.

Many of the plants native to the wetlands will be available at a sale to fund educational programs put on by the organization Watsonville Wetlands Watch who's mission is to protect and restore the wetlands while educating the community.

The Native Plant and Backyard Festival will take place Saturday, September 28th from 10-2pm at the Fitzeriogonum_rubescens Wetlands Educational Resource Center building behind Pajaro Valley High School. It will be their second annual plant sale. Plants beneficial for backyard habitat gardens will be featured many which were grown in their own greenhouses. Natives like buckwheat or eriogonum as they are called are a mainstay of the slough ecosystem as well as our chaparral areas and several varieties will be offered for sale.

One of my favorite eriogonums is the Red Buckwheat for several reasons. In addition to attracting beneficial insects the flowers can be dried and used in arrangements. The roots are deep and will hold the soil and bring up subsoil nutrients to the surface. They are very drought tolerant. In the weeks to come the buckwheat's long nodding flower heads will produce a huge bounty of seed favored by migrating songbirds and water birds, some of which will spend the winter here.

Coast asters will also be available for sale and make a nice addition to any garden. They provide flower color in the fall and combine well with other perennials and grasses such as yarrow and Idaho fescue. They colonize easily and help stabilize slopes and banks and can also be used as an understory plant. They are very drought aster_chilensis2tolerant. Native grasses will also be for sale as well as plants of the coastal prairie and wildflowers.

Besides the native plant sale,  Watsonville Wetlands Watch will have workshops with expert speakers, an Eco Kid Zone, food, a marimba band, a raffle, live animals and local wildlife displays. Free habitat consultations for your own backyard, demonstration habitats, a wetlands wildlife photography exhibit and a tour or their new greenhouse.

For more information about the sale and this wonderful organization visit www.watsonvillewetlandswatch.org

Your own backyard can make a difference for wildlife. Even a small plot of plants rich in nectar and pollen along with some water, rocks, stones and mulch can make your backyard come alive. Create your own backyard habitat by choosing the right native plants to attract butterflies, birds and other fauna and at the same time conserve water and help maintain the diversity of our animal population.