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Garden wisdom from deer country!

Gardening in the Sierra Foothills with Carolyn Singer

The seasoned gardener

published in The Union in Grass Valley CA

THIS fall don't burn a free soil amendment!

by Carolyn Singer
November 8, 2008

Save all leaves falling right now! They provide a wealth of material to compost and enrich next year's garden. Many may be left where they fall. Some will need to be removed from the valuable plants they might bury. But please do not burn them.

Every year uneducated homeowners rake up the leaves falling in yards and may even grumble about the added chore. Satisfied only when the yard is "clean", they make tidy piles to burn. Frequently these piles have wet leaves, adding smoke to our air pollution on "burn days".

However, those gardeners who appreciate the falling leaves as a free supply of soil enrichment actually seek out sources of leaves. Have you noticed bags of leaves disappearing from your curbside? It could very well be that a true gardener has grabbed this valuable amendment. In fact your leaves may be providing fertilizer for a local organic vegetable garden. Think about that when you're purchasing local food next year.

Tree roots reach into the soil and absorb minerals and trace elements, much of which will end up in the leaves. In the fall, the leaves (at least those that are not disturbed by man) will rest on top of the soil and decompose, replenishing the nutrients in the soil. Earthworms assist in this process. A walk in the woods, where the soil has remained undisturbed for many years, will show you how well the natural system works.

In my garden, red maple leaves have been caught by the alpine spirea (Spiraea japonica 'Alpina') giving it a second "bloom" before the leaves fall further and become part of the mulch. The stepping stones under my dogwood (Cornus florida) are framed with fall color.

Lawns and some low groundcovers cannot survive with a heavy covering of leaves, so these garden areas may need to be cleared and the leaves used elsewhere. Small or fine leaves may be left as a mulch at the base of perennials, shrubs and trees, and even some groundcovers. Under my large alder is a beautiful evergreen groundcover, yellow archangel (Lamiastrum galeobdolen). All the alder leaves fall into the groundcover each fall, eventually adding to the mulch with no effort on my part.

Layers of leaves used as mulch around plants may be followed with an application of oystershell (5 pounds per hundred square feet) and a layer of good compost. This mulch will protect the soil, add food for the plants, and reduce irrigation requirements next season.

This practice of sheet composting (layer upon layer of organic materials) may also be used to build good soil, or to protect beds in the vegetable garden. Sometimes I mix decomposed straw with the leaves. And one layer may even be some good garden soil if I'm trying to improve areas of poor soil. I count on the earthworms to help me. They eagerly work their way up to this food I have provided, and by spring most of the materials have decomposed.

With so many leaves available right now, there is no excuse for unprotected soil. Winter rains and winds can do a lot of damage. If you have not cover-cropped your vegetable garden, at least spread a very thick layer of leaves to eliminate compaction from winter rains. A light application of compost on top of the leaves will prevent them from blowing away. Or use wildlife netting to secure the leaves.

Did you plant trees or shrubs this fall? Their surface roots are quickly exposed when soil and compost settle. Grab some leaves from one of your piles and spread a good thick mulch around your new plants. The orange leaves of my tupelo (Nyssa sylvatica) mix with the gold leaves of a nearby maple and even some pine needles, protecting the ground near the tupelo.

An added value of leaves is weed suppression. Seeds buried under a layer of leaves are unlikely to germinate, and even if they do, the tidy seedlings will not find the light they need for growth. However, if you have perennials, biennials or annuals that self-sow, make sure the seeds are scattered on top of the leaf mulch. One fall I spent a month with my sister in Hawaii. A delightful fall break, but the next spring I had no forget-me-nots for the first time in years. The wonderful leaves from nearby trees had covered the flower bed!

Bulbs come up easily through decomposing leaves, so don't be concerned about covering areas where daffodils will soon emerge. If bulbs are already showing (grape hyacinth usually come up by November), add just a light layer of fine leaves.

The black oak leaves and pine needles are more leathery and may take longer to decompose, but they are still valuable for the soil. A leaf shredder or a rotary mower run through a pile of oak leaves will provide material that will decompose more readily. Or add lots of compost to speed the process. Even the leaves of the canyon live oak add to weed control at the edge of my rock garden.

Each year I cannot get enough leaves to satisfy my fall appetite. Besides needing leaves for my garden, and some to add to my compost pile, I also make a separate pile for leaf mold that will be added to the potting soil I use for starting seeds or for houseplants. This week I will be making a "leaf run" to the Cedar Ridge area. Lucky for me that not everyone is gardener, AND that they are wise enough to share, not burn, their leaves.

Save your leaves!!!
Mulch established plants
Protect the soil around new plantings
Prevent soil compaction from winter rains
Build new garden soil
Add to the compost pile
Reduce irrigation next season
Suppress weeds
Create your own potting soil
Share with a gardener
…and enhance air quality by not burning this valuable resource!

©2009 by Carolyn Singer. All rights reserved.

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