The lowly earthworm is really a knight in shinning armor when it comes to garden soil. They tirelessly work to improve water retention and drainage, decrease run off and erosion, aerate the soil, and improve tilth and structure. They also increase nitrogen and the bio-availability of other plant nutrients. They do all this for free and with very little help. All they ask is a safe place to live and plenty of organic matter. You can encourage worms in your garden and let them work for you. Here’s how:
Throw away your rotor-tiller:
I know this might sound sacrilegious to many gardeners, but tillers kill worms. And worms turn soil. While you are out there tilling that soil – risking injury, straining your back, and burning up expensive fossil fuel, you are killing the very creatures that will do the work for you, for free. Tilling soil encourages erosion, topsoil loss through oxidation; and the formation of hard pans. While you are loosening the top layers of the soil by tilling, you are also compacting the subsoil. Repeated tilling on the same plots eventually causes the subsoil to become impervious to water and roots. Worms on the other hand will gradually loosen and aerate all levels of the soil, recycling nutrients that have leached into the subsoil back into plants active root zones.
OK, you ask, if I can’t use my tiller, what do I do? There are many options available to home gardeners. These methods generally involve mulching with plenty of organic matter, or building raised beds. “No Till Gardening” was first made famous in 1959 by Ruth Stout in her book How to Have a Green Thumb Without an Aching Back. Fortunately for us, there is a new edition: Gardening Without Work: For the Aging, the Busy, and the Indolent, published by Lyon Press (1998). A more scientific look at no till gardening can be found in Weedless Gardening, by Lee Reich, published by Workman Publishing (2001).
Feed the Worms:
Worms like organic matter, and plenty of it. They are living creatures; they need to eat. They don’t actually live on dirt, however they do ingest plenty of common garden soil. That soil is used as grit in their digestive process, which also involves beneficial bacteria. (These bacteria fix nitrogen, improving your soil for free!) What fuels a worms metabolism is the organic matter that we burry, mix in to the soil, or use for mulch. As that organic matter begins to decompose worms work their magic.
Worms prefer freshly decomposing organic matter. That organic matter gets mixed with the grit from garden soil, beneficial bacteria, and, well, worm slime inside the worm’s gut. The worm extracts its energy and nutrition and out the other end comes what is referred to as “worm castings.” Lots of research has been done on this substance. Worm castings are high in nitrogen and nitrogen fixing bacteria, which continue to improve the soil after they have been cast. Their digestive process reduces or eliminates harmful bacteria and soil born disease organisms. The castings are also a unique chemically bound composition of mineral soil, worm slime, and organic matter. They have very beneficial effects on plant health and nutrition.
Worms deposit their castings through out the soil and at the soil surface as they go about their business tunneling and searching for food. I find that by the end of summer, any organic matter that I buried in spring has become pure worm castings. When I make my fall planting holes I use those worm castings to top dress my garden. Then I burry more organic matter for the hungry worms and plant broccoli or kale for my own dinner. Fall buried organic matter is usually not completely devoured until the following fall, but the spot can be used in summer by tucking in your plants and providing them with plenty of mulch.
Worms, worms, where are the worms?
If you don’t find several worms when sifting through a shovel full of your garden soil, you may want to purchase some to supplement those that may be hiding. The red wigglers and night crawlers available for use as fishing bait make a dynamic garden duo.
Red wigglers work the top few inches of soil, and will happily consume manure, decomposing mulch, and other organic tidbits. When temperatures turn hot, they will burrow deeper into the ground. If you have buried organic matter down where the soil stays cool, they will thrive through the summer months.
Night crawlers, when well fed, can grow to tremendous proportions. They form semi-permanent burrows and feed at the surface and on buried organic matter. They will also pull grass cuttings used as mulch down into their burrows adding more organic matter to your soil.
Between the two squiggly creatures your soil will be thoroughly cared for. Just make sure you have a shady spot with good drainage and plenty of organic matter before you hire them on. They will multiply and spread through out your garden with very little effort on your part.
Besides saving your back, and improving plant nutrition, worms benefit the soil in many ways. The very slime that glues the organic matter to the mineral soil in worm castings prevents erosion and top soil loss. This glue reduces the ability of the soil dissolving in water and getting washed away by normal irrigation. The granular nature of the castings reduces the soils ability to turn to dust and get blown away. The physical structure of the castings also benefits plant roots. Worm castings resist compaction (unless you work at it). The spaces between the castings provide room for air and moisture in the soil. And the loose structure of the castings are easily colonized by plant roots.
Worms are wonderful. They improve the soil both nutritionally and structurally. If we let them, they reduce the work of gardening immensely. They are out there right now, waiting to go to work for you.
For more information see the following articles from my blog:
A Simple Garden Routine – useful for bad backs, no time, short budgets – this arrticle tells in detail exactly how to garden for the worms. http://harvestsgardeningsecrets.blogspot.com/2006/01/simple-garden-routine-useful-for-bad.html
If you missed the article on organic matter, Nurture Your Soil for Free, you can read it here: http://harvestsgardeningsecrets.blogspot.com/2006/05/nurture-your-soil-for-free.html (Or you can go to the blog and use the search function to find information on worms, soil, and organic matter: http://harvestsgardeningsecrets.blogspot.com/ )
For the low down on the research related to worms and gardens check out this site:
I’ll meet your back here next week to explore basil’s many delicious varieties. Mean while you can probably find me out in the garden, Digging the Dirt.
Copyright 2006 Harvest McCampbell, from my column “Digging the Dirt,” published in The Hoopa Valley People Newspaper, June 20, 2006. Posted here with permission.