pruning tips

Tree Pruning Tips

Leave a comment

limbed redwoods.1600The big wind we experienced not long ago was just the beginning of the wild weather that is coming our way. Looking up at the trees violently swaying from one side to the other I wondered how they could survive such strong wind gusts. Not all of them do survive coming down and blocking driveways, roads and sometimes landing on a house or a car. There are ways of trimming, pruning and managing trees that can help them stay upright in a strong wind. Don’t endanger yourself, your family, your property or your valuable trees by mismanaging this valuable resource.

You’ve seen it. A homeowner wants more sun and has their redwoods limbed way up so there is just a a tuft of branches and foliage at the top. Living in the forest myself I can understand the desire for more sun. Why is this bad for your trees? What is a better way to ensure the health of the tree and still have space to walk or park under them or open up a view?

Raising the height of the lowest branches or limbing up is often done to create clearance in an area where people will walk or park. Seven feet is your target height . Over pruning removes many of the energy producing needles and leaves taking away most of the trees ability to photosynthesize. Evergreens don’t have food reserves like deciduous trees. They may even die completely in 8-10 years or topple in a heavy wind because they have become so top heavy and have lost their windbreak effectiveness.

Removing the lower limbs of redwood, cedar, pine or other conifer is needed to remove dead and dying branches which improves circulation and makes them more fire resistant. It’s done naturally in the woods when limbs die and fall off. If you must remove live lower branches do it over a longer period of time to reduce stress on the tree. The amount trimmed off should not exceed 25% of the total foliage. 10-15% is better but not always attainable.

Windowing of a tree should follow the same guidelines. To open up a view and preserve the health and beauty of your trees, here are some ways to make views and trees work together. According to Plant Amnesty, windowing or cutting selected branches, works best when the subject is a large, close-in tree blocking your view. By carefully choosing what to cut you can open a window in that tree to give you a fully framed view of whatever lies beyond. Like most pruning, there’s a certain amount of art involved in this. Never top a mature tree it’s arboreal butchery.

If you’re trying to decide whether or not to limb up evergreen trees in your yard, do your homework first. Oregon State University Extension Services recommends pruning when the treclear cut hillside.1600e is not actively growing. This is late winter to very early spring, well before any new growth will take off in the new season. For our area January and February is best. Redwoods go into a short period of dormancy at that time making it the best time for pruning. This gives them a chance to heal the cuts you make with their first burst of new growth in the spring.

Another scenario that wreaks havoc with the land is to clear cut large sections of forest. When you do this the trees left behind on the fringes are not prepared to deal with high winds. They grew up being protected by the trees around them and their trunks are not as strong. Trees channel the wind over the top and buffer it before it hits the ground. By clearing the land completely the wind barrels through the open area and hits the next thing in its way which may be your house or deck or landscaping. It’s better to remove selected trees completely.

Put away the saw and enjoy the beauty of your mature evergreens. Prune lightly. Preserve your trees natural shape. A properly pruned tree will look as natural as possible.

beneficial insects, composting, cover crops, edibles, green manure, mulching, organic fertilizers, organic gardening, organic weed contol

Growing Cover Crops – Part II

Leave a comment

Orin_Martin_bell_beansOrin Martin of the Alan Chadwick Garden on the UCSC campus is widely admired for his incredible knowledge and skills as a master orchardist, horticulturalist and teacher. I was lucky a couple of years ago when he visited a group of fellow designers and brought his favorite russet apples. Another time he brought a dozen different kinds of potatoes that we roasted, critiqued and thoroughly enjoyed.

The Alan Chadwick Garden was nothing but poison oak and chaparral in 1967 when Alan Chadwick first got his hands on it. Martin came to UCSC in 1969 as a literature major but was soon impressed with Chadwick’s work, preaching the gospel of treating the garden as a self-nourishing system. Together they worked the garden, building the soil and teaching others.

Now Martin runs the appreaster_Michaelmas_daisy.2048ntice program which teaches future organic gardeners and shares his knowledge in workshops like the Cover Crop class I recently attended.

Last week I wrote about how and why to plant cover crops. This is what to do next spring after they’ve done their magic in the soil fixing nitrogen.

Cover crops are plowed or skimmed off in late February to early April. Because it takes 3-5 weeks for the cover crop to break down so crops can be seeded or transplanted, it is often best to skim off the cover crop at the base of the plants and combine with straw or leaves to make compost. Previously made compost can then be applied to the surface. It is important to retain the roots and nitrogen-filled nodules in the soil. Take only the vegetative portion.

cover_crops_Orin_Martin.1280Another method is to skim the foliage with a weed wacker or mower chopping it into small pieces 1/4″ to  4″ long. You can then rototill this into the soil and allow it to decompose on its own. In about 2 weeks the material should be broken down to be unrecognizable as plant material before replanting.

If you are developing your soil to build organic matter and improve structure incorporate the cover crop at a more mature stage (half to full bloom) when it has a higher carbon content. The nutrients will be stored in the reservoir of humus and released slowly over a number of years.

On established soils where you want primarily to fertilize next spring and summers crops, incorporate the cover crop after skimming and chopping when it has just started to flower as it decomposes quickly at this stage.

The Chadwick Garden fertilizes its established fruit trees by simply cutting down the cover crop growing at their base with a machete at the 25% flowering stage. 4-6″ of wood chips are laid over the chopped up pieces and left for nature to decompose. That’s all their is to it. Martin explained that the garden used blood meal and the organic fertilizer, Sustane, during the first several years while the trees were becoming established.

Picking up a clump of grass sown just 2 weeks ago, Martin teased off the soil to show the vigorous, fibrous root mass. “This is why the riches soils of the world, the Steppes of Russia and the original Midwest prairies, are so fertile and are called bread basket soils”, he explained.

Plant a cover crop this fall and your soil will be richer for it.

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

Leave a comment

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.

The Mountain Gardener's Weblog