Design trends

Cover Crops Enrich Soil & Prevent Erosion

A mixture of grasses and legumes grown as a cover crop and tilled into the soil in spring increases soil fertility.

If you’ve been waiting to plant a cover crop , wait no more. The soil is now moist and still warm enough to germinate seed easily. Remember that every drop of rain that hits bare soil is destructive. Over 3000 years ago the Chinese protected their soil from erosion and increased fertility by planting cover crops. Early Nile Valley inhabitants 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. Planting a cover crop is another way to improve and retain your soil.

A cover crop is really anything that covers the soil and protects it from rain, trapping nutrients and preventing them from leaching downward. 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 inches 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. Growing a cover crop also increases beneficial soil bacteria.

Cover crops are called green manure when they are chopped up and turned into the soil in spring before 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.

Now through 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.

Recent research now recommends planting a mixture 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%.

Orin Martin of UCSC Chadwick Garden demonstrates the remarkable root structure of bell beans.

There are other legumes that fix nitrogen but nowhere near as efficiently as bell beans. Crimson clover seed is 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.

You don’t need to use inoculants on legume seed. 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.

Work the soil lightly with a metal bow rake then broadcast 8-10 seeds per square foot. Weeds should be already cleared but this step doesn’t have to be perfect. Afterward the area should be raked again lightly 1-2 inches down and covered with 3-4 inches 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. Water in lightly.

If you plan to let your small vegetable garden lie fallow over the winter instead of planting it with a cover crop you can cover it with manure and straw.

Design trends

The Holloween Garden

The Cinderella pumpkin “before” carving by Scarlett Biles

Halloween is just around the corner and besides deciding what you or the kids are going to be this year, it’s time to bring in any plants that you plan to overwinter in the house. Whether they’re the houseplants that you put out on the patio for the summer or frost tender plants that you want to save, this is the time to bring them in and here’s why.

Although our nights are still above freezing, plants need to acclimate to the indoor environment before you start turning on the heater regularly. Be sure to wash them thoroughly and inspect them for any insects that may have taken up residence while they were vacationing outside. Usually you can dislodge any hitchhikers with a strong spray of water but if that doesn’t do the trick, spray them with a mild insecticidal soap or one of the other mild organic herbal sprays like oil of thyme.

Another tip: Fall is not a good time to prune. Wounds heal slowly, leaving them more susceptible to disease. As a general rule, don’t prune when leaves are falling or forming. Wait to prune most trees until late in the dormant season or late spring after leaves and needles form. To avoid sap flow on birches and maples, prune after leaves mature.

If you want to decorate for Halloween there is plenty of plant material you can harvest from your own garden or nearby woods. Manzanita branches can often be found on the ground and make great arrangements combined with nandina or other berries. Some of the trees have started to turn color and their leaves can also be used for wreaths. The leaves of New Zealand flax last a long time and add fall color in bouquets.

Mums are the classic fall flower. They come in nearly every color except blue and the flowers have many shapes from daisy to spider mums. They are perennials and make good additions to the garden. Best of all they make excellent cut flowers.

Several years ago a friend gave me a Blue Hokkaido winter squash to decorate my front entry and eat afterwards. It was delicious. Another year, a good friend gave me a Cinderella pumpkin (Rouge viv d’Etampes) he grew. IIt’s said to have been the inspiration for Cinderella’s carriage. This French heirloom pumpkin was very popular during the 1880’s and will be tasty in pies and savory dishes later this fall. For now, the glowing orange-red color contrasts magically with the very pronounced lobes and flattened top.

The Cinderella pumpkin is one of the very best for growing, cooking, eating and storing

Many gardeners feel the Cinderella pumpkin is the very best pumpkin to grow in your garden. It’s the first to set fruit, first to ripen and is mildew resistant. Their bright orange creamy flesh is perfect for baking. Oven roasted they produce a pumpkin puree that is neither watery or bitter. Delicious in pumpkin spice muffins, pumpkin soup, or with vegetables and sausage. I even found a recipe for pumpkin mac n’ cheese baked in a pumpkin. I’m so excited.

Pumpkin was a staple food for the early pioneers. It was easy to grow as a few seeds dropped into a shallow hole grew into a mature fruit. Yes, technically they are a fruit not a vegetable along with summer and winter squash and gourds. Their thick rind would allow them to be kept almost indefinitely.

If you decide to grow the Cinderella pumpkin next year, you can start inside in pots or wait to plant in the ground when night temps are 55 degrees or over. In the garden, group them with other deep rooted plants that grow rapidly and need lots of water such as corn, cucumbers, melons and tomatoes.

Design trends

Favorite Japanese Maples

A Sango Kaku Japanese Maple in fall color

I have two Japanese maples on my deck. They are not nearly as large as those I had up in Bonny Doon but you have to start somewhere. One is a common acer palmatum seedling and the other a ‘Sanguo Kaku’. They have not started to show any fall color yet. It’s been a hot summer as you know.

Many of you readers were evacuated last summer and your garden did not get watered. This summer has been hot and everyone is trying to conserve water. So if your Japanese maple has suffered from hot weather, smoke and just plain tough conditions you may not get a spectacular fall foliage display this year. I see trees of all kinds going into an early dormancy showing a touch of fall color only. Every year is different.

Other things besides hot weather and not enough summer water to consider regarding fall coloring is that it can be disrupted by wind and rain coming at the wrong time. Japanese maples have a more delicate leaf than some of other trees and are more susceptible to the elements of nature. We most likely won’t get rain spoiling the display but wind during this time will put a quick end to the autumnal display.

At a local wholesale nursery recently I walked through their 36 inch box Japanese maple specimens getting ideas for future projects. Several that caught my eye included the variegated ‘Butterfly’ and ‘Oshio Beni’ with its orange and crimson fall coloring. Other notable maples that display vibrant fall coloring included ’Seiryu’, an upright laceleaf variety which turns bright gold, yellow and crimson in the fall. Also beautiful, the ‘Autumn Moon’ maples promised varying shade of gold to red.

Leaves change color when they are going into winter dormancy. When nights get long enough, leaves develop a corky layer of cells between the leaf stalk and the woody part of the tree. This slows the transport of water and carbohydrates. The manufacture of chlorophyll is slowed and the green color of the leaves begins to fade, allowing the other pigments to show through. Since the transport of water is slowed down, food manufactured by the remaining chlorophyll builds up in the sap of the leaf and other pigments are formed which cause the leaves to turn red or purple in color depending on the acidity of the sap.

For example, sumacs and California wild grape almost always turn red because red pigments are present and their leaf sap is acidic, While many of the oak and sometimes ashes will get a purplish color because the sap is less acidic. Trees like birch don’t have much orange pigment, so they appear mostly yellow in the fall. Others don’t have much yellow pigment and turn mostly orange or read. Some trees have a balance of pigments and look pinkish. The brown color or many oaks can be attributed to a buildup of tannins which is a waste product in the leaves.

So don’t miss out on Japanese maple season. You won’t regret getting a new one for your yard or patio.

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