Since 1990, City Farmer and the City of Vancouver have held worm composting workshops for City of Vancouver residents who live in apartments. For $25 participants get a worm bin, 500 worms, Mary Appelhof’s book “Worms Eat My Garbage”, a trowel, bedding and a one-hour class. Now that’s a deal!
Worm Castings are like BLACK GOLD to your garden, and high quality store-bought castings are just about as expensive! For good reason. They cause seeds to germinate more quickly, seedlings to grow faster, leaves grow bigger, more flowers, fruits or vegetables are produced. Vermicompost suppresses several diseases on cucumbers, radishes, strawberries, grapes, tomatoes and peppers, according to research from Ohio State extension entomologist Clive Edwards. It also significantly reduced parasitic nematodes, aphids, mealy bugs and mites. These effects are greatest when a smaller amount of vermicompost is used—just 10-40% of the total volume of the plant growth medium is all that is needed!
Worms are easy to raise or you can use a complex system. You can start them anytime, indoors or out depending on temps. Here in Santa Barbara mine live outside all year in full sun. They are more active when they are warmer. Non color inked newspaper is often used for bedding to start a clew (colony). Worms are 90% water, so keep the bedding moist. My worms get all the moisture they need from the juicy kitchen bits I feed them and that I cover them with their plastic blankie to keep them moist!
They like decomposing kitchen waste with the exceptions of spicy, acidic, and meats (too tough). No junk food. Coffee filters, grounds, lightly ripped teabags are good, but not too many of those because they are acidic, and veggies like things a tad alkaline. Things cut into smaller pieces decompose faster. Harder or tougher items take a long time. I don’t ‘feed’ mine avocado pits because they literally can’t eat them. They do love the avo shells though and nest in them. Egg shells keep the pH neutral.
You can easily see when they have run out of food. Feed them sooner than that, or they might be hungry a few days, even die. They eat the bacteria on what you give them. They can’t eat raw food until it decomposes a bit. Hit up your friends that juice for a high quality steady supply of fresh organic veg and fruit trims and bits. Avoid acidic citrus, sulfuric onion, pastas (not a fruit or veg), but go wild with carrot peelings and tops, funky lettuce, melon rinds. Fridge clean outs are perfect for your worms!
The quality of what you feed your worms is the quality of your castings. Real nutrients, like the organic wastes of nature, give you excellent castings in return. Worms will eat non nutritious cardboard and lots of other things, but why? Better to recycle that in other ways.
The right kind of worms are RED WRIGGLERS! They forage on debris above ground. They are smaller than earthworms that live IN the earth. Fishermen use them for bait. Ask your fellow gardeners to give you a handful to get started, or go to the bait shack, or a local organic worm dealer. The little guys live about 2 years. My clew has been going strong for 12 years now.
Housing! Since they are surface foragers, these worms need width, not depth. Mine live in a low 4′ by 2′ opaque grey storage container. I put holes in the bottom for drainage, holes in the cover to let hot air out in summer. Inside the container I cover them with a large black plastic bag to keep it moist and dark for them. They feed all the way to the top because they feel safe no birds can see them!
Harvest the bumpy like little castings, look like fluffy coffee grounds, they push up to the surface. You have seen castings, often after a rain. Earth worms push them up into little textured piles on the soil’s surface. I use an old coffee container with a handle. Take the ‘blanket’ off your worms. Give them about 5 minutes to dive out of the light. Gather the castings at the top. Wait a few more minutes for them to dive again, then gather some more.
Feeding your plants I walk about my garden to see who might need some castings, or where I plan to plant. Scratch out a shallow area. Most veggie annuals do all their root growing in the top 6 to 8 inches of soil. Spread some castings in, cover them with the soil you dug out. After you have used all the castings, water the areas lightly so the castings stay covered and moist. Remember, you don’t need but 10-40% castings of the total volume of what you are growing your plants in.
How Castings Work! Castings are not exactly a fertilizer, ie their available N, Nitrogen, content is only 1.80 – 2.05 %, yet their NPK value is much higher than soil! NPK are the main minerals your plants need. The NPK in castings is locked in the cast, and slowly released as micro-organisms break it down. This is much better for plants, because it takes time for them to uptake nutrients. They can’t do it all at once.
Vermicompost nutrients and minerals are significantly higher (with Nitrates up to 9 times higher) than garden soil. This creates electro-conductivity, in turn creating more salts in vermicompost. When there is too much salt in soil, it sucks water from plant roots resulting in the ‘burning’ of plants. Although there aren’t enough salts in vermicompost to do that (it is much more common in chemical fertilizers), using too much wormcast can stunt plant growth.
Optimum growth is in a soil ratio of 1:4, that’s 25% castings, 75% soil. However it has been shown that even 10% of wormcast shows significant difference in plant growth. Using over 40% castings, plant growth performance is stunted and may even appear worse off than having no wormcast at all. A wise gardener knows more is not always better. And, your precious castings will go further.
An even more clever gardener will make a drain at one end of the box and collect the worm tea! Check out Bentley’s post for some of the finer details to consider and how to process your leachate for maximum results. If you aren’t doing worm tea, move your worm box from time to time so that juice can drip into your soil, making it rich and nutritious. Plants will grow like crazy there!
Plant recovery! L.A. Times, 5/27/00, Julie Bawden Davis: “Convinced that nothing could help a whitefly infested hibiscus in my garden that had been struggling for two years, I spread a one inch layer of worm castings around the plant. A month later I noticed that the whitefly population had dwindled. Three weeks later there were absolutely no whiteflies on the plant. It’s now back to its healthy self and producing lots of blooms.”
To my delight, visitors often wonder if I have named my worms! We all laugh and I show them more worms! Oh, and how do you get more worms?! Worms are hermaphrodites, meaning each worm has both male and female reproductive parts. The worm does have to mate in order to reproduce, but, every worm they meet is a potential mate. When a worm gets to be about six weeks old it forms a white band around its head, called a clitellum, this is where their reproductive organs are located.
Under ideal circumstances, worm populations can double in a month. They begin breeding at 2 months old, are capable of producing 96 babies each month. Worms have a brain and five hearts. Worms breathe through their skin. They have neither eyes nor ears but are extremely aware of vibrations such as thumps or banging on the composter. Please try not to disturb them unnecessarily. Worms are odorless and free from disease.
Worm Economics and Education! Vermiculture has become common practice. Private Worm Farms abound! Universities and schools have educational programs, cities have programs, zoos, private organizations proudly tell their story. Websites assist you about raising your own or starting your own business.
Buying Castings! No time for one more thing to do?! Get your castings from a reputable organic seller. There are many great companies with high quality castings today. Don’t confuse an amendment, with castings added, with a bag or bucket of pure castings. Remember, a little bit of the right stuff goes a long way. Give them to your indoor plants too.
Whether for prevention, nutrition, recovery or economics, worm castings are fabulous. Worms work for free, and are sustainable!