Ten Secrets to a Successful Start in the Garden: Secret #3
by Rommy Lopat

ARTICLE FIRST APPEARED: 1997 Spring

Diagnose Correctly -- Treat Accordingly

First, honor what Mother Nature gave you as your soil. Whatever kind of soil you have--sand, silt, or clay--it has a particular structure. You may have several soils on your property, and you must consider each one as a different "garden type" suited to particular plant types or root types. As soon as you put a shovel in the ground, you will be changing the structure of the soil. Beware!

The goal of the gardener is to develop soil that not only has lots of organic material, but also has an active microlife that constantly eats the organic matter. The microbes determine the amount of nutrition available each day to the plant's roots. When clay soil becomes compacted, there are fewer large pore spaces. While air is still exchanging and water is still present, they have Ôslow going' through the soil. The microbes don't eat, the organic matter doesn't decompose, and the humus (which creates the soil structures that in turn create the tilth that guards against compaction) is not formed. Compaction is easy to do: nature's everyday wear and tear on a soil can reduce plant growth by 10 percent (USDA report). No amount of fertilizer or additions of mycorrhizal fungae can compensate for lack of air: you're suffocating the roots and the microbes!

A few suggestions:

• Work a clay soil only when it's moist; any other time (too wet; too dry) and you are back to ruining its structure by compacting it or pulverizing it. Don't demand that your landscaper work in the rain or extreme drought; indeed, insist that she go home unless she never leaves the stepping-stones.
• To create a garden in heavy clay, you can double-dig 50-60% aged compost by volume into the soil or create a raised bed of same. Dig the aged compost in as deep as possible: adding aged compost to the surface won't improve the soil's aeration if the soil underneath is hard.
• Add aged compost every year. Best to dig it in but mulching with it in amounts of 1-3" will be ok. If you add more, make sure you dig it in deeply. Simply putting a thick layer on top of the soil every year is extreme: you are creating a new soil layer that is very porous, and the microbes will not travel up into it. Also, roots planted in such a delicious mix will never leave it to go deeper. But without aged compost added every year, the soil will revert to its old self.
• Make sure the compost you use has been aged for about 4 months and is no longer hot or you risk salt damage. If you're using fresh organics, try 50/50 shredded leaves and grass for perfect balance. If using fresh wood chips, sprinkle some nitrogen underneath first.
• Have soil tests performed every 4 years so that you understand the nutritional level of your soils.
• Plants with great big root systems are the best "clay busters", a term coined by Neil Diboll of Prairie Nursery. Black-eyed Susans, Liatris, New England Asters, Joe Pye Weed, Big Bluestem, Little Bluestem, Purple Coneflowers, Beebalm, White False Indigo, Canada Wild Rye, Indiangrass, Switchgrass, Culver's Root, and Ox-Eye Sunflower do fine in clay and help mix it. They are Mother Nature's answer to clay soils. But don't expect even the prairie plants to do the impossible: you must help open up any concrete-like clay first.
• Builder's sand added to clay will change its texture and help maintain its large pore spaces, but only in very large amounts. [Consult the UofI publication, "Amending Soils with Sand", (217) 333-2007, before trying this yourself.]
• Incorporate high-fired clay products like ÔProfile Professional Clay Soil Conditioner'. An anti-compactant that also holds water and nutrients until needed, Profile is being used in the new TWG garden.
• Core aerate your lawn every year.
• Create a earthworm "catcher" (a large rock with moist soil underneath). somewhere in the yard. Go harvest the earthworms on a regular basis, and put them in your garden. They are Mother Nature's rototillers. I'm told that the earthworms you buy through the mail are a waste of money. Native worms, not "exotics"!
• Don't overtill. 1 or 2 passes with a rototiller in the garden is plenty. Better to have a few lumps than to pulverize the structures in the soil. Balance! Balance!

SOIL TEST LABS

For a list of the many labs located in the region, contact your Coop. Ext. Service.

A&L Great Lakes Lab
3505 Conestoga Drive
Ft. Wayne, IL 46808-4413
(219) 483-4759
ÔBeyond the basics' tests at various prices.

Green Gems
PO Box 6007
Healdsburg, CA 95448-6007
(800) 431-SOIL
This is a mail-based testing kit which is also sold in garden centers. The actual lab work is performed by A&L Great Lakes.

Woods End Research Lab
PO Box 297, Old Rome Rd.
Mount Vernon, ME 04352
(207) 293-2457
In April, Woods End will debut a home-test kit for soils similar to one they have for measuring the maturity of compost piles.

Ag Source Coop Services (aka The Soil Doctor)
106 N. Cecil St.
Bonduel, WI 54107
(715) 758-2178
The tried & true basic test.

(TOP OF PAGE)