Importance of Garden Worms
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What Are Garden Worms?
Garden worms are those long, slender, soft-bodied animals that do all kinds of good things like improve the soil and provide nutrients for plants. Some, like red wigglers, live close to the surface, eat lots of organic matter and are used for composting. Others, like night crawlers, live deeper in the ground and create tunnels that aerate and improve the soil. These worms are often considered the best worms for vegetable gardening.
What Are the Benefits of Adding Worms to Your Garden?
Adding worms to the garden improves the soil and plant health in several ways. Garden worms eat organic matter and fertilize the soil with their castings, or worm poop. Worm castings provide nutrients to plants. When worms for the garden tunnel in the soil, it loosens the soil, allowing water to percolate through it. Looser soil also lets in more oxygen and allows plant roots to penetrate deeper into the soil.
What Can Earthworms for Gardens Do?
Earthworms for the garden, or night crawlers, are most valued for loosening the soil and improving the soil structure. These hard-working worms can tunnel through clay soil and compacted soil, allowing more air and water to move through the soil. These worms will penetrate the soil quite deeply—often several feet underground. They also provide nutrients to the soil with their castings.
Best Worms for Composting
Worms speed up the composting process by eating organic matter and then enriching the soil with their castings. If composting indoors, red wigglers or red worms are preferred. These slender worms, often 1-3 inches long, can survive in warmer temperatures and live just a few inches under the soil surface. They also tolerate the more crowded conditions of indoor worm composting bins. Red wigglers or red worms can be used in outdoor compost bins, but may need some protection from extreme heat and cold temperatures.
Best Worms for Vegetable Gardens
Larger worms, such as night crawlers, are favored in the garden. Because these garden worms dig deeper into the soil where the soil temperatures are around 50 degrees F., they can survive when air temperatures are extremely cold or hot. Because they eat more dirt than organic matter, their castings are not as rich as worms used for composting. However, the garden worms, or night crawlers, break up the soil with their tunneling.
How to Maintain Garden Worms
After adding worms to the garden adopt some garden practices to ensure they'll survive and thrive in the garden. Here are some tips:
- Start a compost pile. Worms will come and feast on the organic matter.
- Avoid tilling. Tilling can destroy the worm tunnels and the good soil structure.
- Avoid using pesticides that can kill worms.
- Provide worms with food by adding organic matter, such as compost, lawn clippings and leaves, to the soil.
- In the fall, leave the vegetable roots in the soil so the worms can break it down.
Using Worms for Gardening - Expert Advice
Q. Mike: Should I add earthworms to my raised beds?
- ---Chris in Summit, NJ
- 1): To help keep my soil aerated and pliable and fight the dreaded "ClayAchin'" of Delaware County, PA. &
- 2): To have a supply I can dig up and use to go fishing whenever I want. I have an empty 4' by 4' raised bed all ready for my worm condo. I just need advice on how to furnish it. Thanks,
- ---Pete in Glenolden, PA
A. Well, first I have to thank both of you! To use Pete's 'two fold reasoning': One, because I checked our archives and was totally—like totally!—embarrassed to see that I haven't done a detailed piece on worms yet. And Two, because your questions led me to rediscover "The Worm Book" by biologist, entomologist, & zoologist Janet Hogan Taylor and 'eco - journalist' Loren Nancarrow. This lively little tome, first published by the great Ten Speed Press back in 1998 and (thankfully!) still in print is full of wormy fun and helpful facts.
The answer to Chris' question about adding earthworms is both simple and complex. Earthworms (like the abundant night crawler) are wonderful in garden situations. Give them some leaf litter to live underneath and they will constantly digest your garden soil, aerating it to relieve soil compaction and adding lots of trace minerals and other plant nutrients in the form of their famous 'castings', a euphuism that certainly sounds much classier than the 'worm poop' it is. Appreciation of these worms is one of the big reasons I use shredded leaves as the mulch of choice in my raised beds; I know that almost every time I move some of the mulch to one side, I'll see earthworms scurrying away to hide.
But allowing such worms outside a wriggly-good garden gets tricky. There is a strong consensus in the scientific community that many of the nation's earthworms are not native to the Americas, but came to our shores from Europe and Asia in the soil accompanying transported plants; and The Worm Book notes, in huge numbers when the ships of early settlers used soil for ballast and let it loose in The New World. These practices apparently re-introduced earthworms to areas where they had thrived in prehistoric times, but had been wiped out during The Little Ice Age. A lot of controversial plants in our landscapes have very similar histories. Do such origins make these organisms alien invaders? Or resettled natives?
No matter which way your brain tries to unpuzzle that puzzler, these earthworms seem to be changing the face of the American forest floor with their nutrient recycling. Although a richer soil would seem to always be a good thing, it favors the growth of some plants over others; and the fear is that the worms are putting added pressure on some native species.
So, as my good friend Frankenstein's Monster would simplify this complex question: "Worms in garden, good! Worms in forest, bad! Bad!"
I note this seemingly academic point because of Pete's desire to drown worms in pursuit of an aquatic meal or twelve. Fishermen—eh, fisher-persons—have gotten much of the blame for introducing these 'foreign' worms to forested areas, specifically by dumping their extra bait after a hard day of napping next to an anchored fishing line. So make it like trash in a national park: If you take it in, you haul it out. Or as our distinguished ex-president might say, "Leave no worm behind." (Which, of course begs the follow-up question: "Is our worms learning?")
In any event, the earthworm of choice for home gardens would be the night crawler (Lumbricus terrestris), a species that has become abundant (or is that re-abundant?) in North America. Unlike the redworms used for indoor worm bins, these worms like to go down deep—up to six feet under. The Worm Book notes that they prefer undisturbed soil for their permanent burrows, so if lots of worms you want, do no tilling. The less you do to disturb your soil, the more worms you'll have.
As their name implies, night crawlers come to the surface in the evening, so that's the best time to harvest a few for the next morning's fishing trip. The book adds that they're most active in the Spring and Fall; in winter and summer, they stay way down low during times of temperature extremes. A chilly (to me anyway) 50 degrees F. (10 C.) is their preferred number. I would think that a thin layer of vegetable waste from the kitchen on top of your soil covered with well-shredded leaves would provide the food they like to find near the surface and the cool soil temps they prefer.
If your garden area seems to currently be worm free, you might try some local wrangling to collect starter worms. A small-scale business in some areas, worm wranglers strap miner's lights to their forehead and go out collecting on rainy nights. And, you know, if these worms ARE causing problems in forests, it might be a mitzvah to collect them from the woods and take them to gardens.
Just remember: Night crawlers need to go down way deep and are not appropriate for indoor worm composting bins. And the redworms sold for use in indoor bins are not fit for gardens. You need the right worm for the right job. For lots more information on this topic, get a copy of The Worm Book. And read it until the pages are 'worm-eared'.