The unsung heroes that will bring rewards to your garden next spring.
We often stated that it is a very good idea to rake the leaves off of your lawn and onto your garden. The leaves will mat down with rain and weight of snow and begin to break down into a quality layer of organic matter. Come spring, when temperatures reach 10 C, the earthworms move up to the surface of the soil and, upon discovering a fine harvest of leaves, munch on them until they disappear.
Take a trip out to your garden on the Canada Day holiday and we guarantee that evidence of your leaves will be gone.
So, what happens to them? Glad you asked. This is December, the month to celebrate all of the good things in life and without a doubt, earthworms are one of them.
A gift to gardeners
Earthworms are part of a biotic community. They, along with centipedes, sow bugs and a variety of other useful earth-bound critters, provide an invaluable service. When earthworms arrive at the surface of the soil, they consume the carbon-rich fallen leaves (and leaf mould). These are mineralized by microorganisms inside of the earthworm's gut. As the leaves pass through the sophisticated digestive system of the worm, they are converted into nitrogen-rich earthworm 'castings.' As the worms move through the soil, sometimes as deep as a metre, they constantly leave these castings behind. They are a gift to the gardener.
The castings quickly stabilize and become resistant to chemical and physical degradation. They enhance the quality of your soil by stabilizing and storing nitrogen and carbon until the microbes in the soil break them down. As the worms move through your soil, they open it up, essentially aerating it, making oxygen available to the roots of your plants. Every plant on earth benefits from oxygen at its root zone.
With healthier roots your plants will perform better, the need to fertilize is minimized (or it disappears) and water moves through the soil more efficiently. Plants more easily channel their roots through the tunnels created by the earthworms.
Transported from warmer climes
While we could assume that earthworms do their work as part of some big, master plan on the part of Mother Nature, it is worthwhile noting that there are no native earthworms in Canada. If they existed at one time, as fossils suggest they did, they were wiped out by the last Ice Age. Your friendly neighbourhood earthworms are immigrants. Either they moved up here from the deep south, where the glaciers never existed, or people brought them over here from Europe during the great plant importing schemes of the 1700s through to 1940.
To nurture the worm population in your yard, it is useful to know:
- Worms prefer loose, open soil. Turning your soil each spring helps to encourage them.
- They are moisture-sensitive. During drought they move deep into the soil and enter a resting phase. In heavy rain, they move to the surface of the soil to escape the lack of air in their tunnels.
- One active worm will process up to one fifth of a kilogram of organic matter per year.
- An earthworm can live between three and 10 years, depending on species and soil conditions.
The toad touch
Another hero of the garden is the common toad.
They feed on a wide variety of insects and have quite an appetite. The insects that they eat are often a nuisance in the garden, so you want to encourage toads as much as possible. Slugs and mosquitoes are just two of their preferred prey.
They overwinter deep in the soil and will travel up to half a kilometre to reach a breeding ground come spring. Males often get a free ride on the back of a female. Perhaps we should make up a new expression "couch toad" to describe certain males of the human species.
It takes about two years for a toad to mature to full size, but they live for up to 10 years.
To encourage a population of toads in your yard, we suggest that you leave some leaves on the soil (another reason to do this!), do not 'sanitize' your garden by removing all of the perennials and mulch that is there this time of year. Give them shelter and they will reward you next season.
Toads and earthworms are just two of the unsung heroes of the garden. Together they are essential weapons in our war against poor quality soil.
Mark Cullen is a Member of the Order of Canada. He reaches over 2 million Canadians with his gardening/environment messages every week. Receive his free monthly newsletter at www.markcullen.com Ben Cullen is a professional gardener with a keen interest in food gardening and the environment. You can follow both Mark and Ben on Twitter (@MarkCullen4), Facebook (https://www.facebook.com/MarkCullenGardening/
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