Instead of sending food waste to the landfill or grinding it down the sink, let red wiggler worms recycle your scraps into soil amendment. I am a HUGE fan of composting with red wiggler worms – a process known as vermicomposting.
Why might worm castings be good for the garden?
Worm castings, also referred to as compost, vermicast, worm humus and worm manure, contain nutrients that are easily taken up by plants: especially magnesium, phosphorus, potassium and calcium. Red wigglers filter out pathogens and aerate the soil. The trace minerals, beneficial bacteria and fungi in castings make them an ideal soil conditioner and growth enhancer.
Vermicomposting produces results much faster than traditional compost bins or piles. Several university studies show that the resulting product can be significantly more beneficial to the garden than traditional compost, even compost containing animal manure (depending on what was fed to the worms).
I credit worm castings for many of my garden success stories. The summer before publishing this book I grew loofah gourds. People will tell you they need to be planted in the ground in lots of space. I planted one seed in a medium-sized grow bag filled only 8 inches deep. It produced three good-sized gourds. Adequate water, warm temperatures and sunshine helped but an occasional sprinkling of worm castings probably made them grow to their potential.
While I wouldn’t use pure castings as a growing medium, this is the one ingredient you can use liberally in the garden.
Where do I find worm castings?
Worm castings off the shelf are not cheap. A small bag from a farmers market vendor could run you $20! People purchase worm castings from professional worm farms, individuals, garden shops and online retailers. I’ve loaded my truck with 50 pound sacks of worm castings. You can also get it by the square yard!
Instead of opening up your wallet, open up your mind to keeping worms as pets and compost generators.
To start composting with worms, you will need to acquire red wiggler worms. Red wigglers perform differently than the earthworms you find out in your yard. Earthworms won’t like being your pets and they won’t eat your scraps as efficiently. I created a guide for you that simplifies the process of setting up your bin – the same method I use today.
If you’re lucky, a worm farming friend will give you some for free. If you don’t have connections in the gardening underworld, look on Craigslist.org, purchase over the Internet or visit your local garden center. You will be surprised how easy it is to acquire a starter set of red wiggler worms. Don’t worry if you get mostly tiny worms in your starter batch. The younger they are, the more resilient they’ll be when trying to get used to their new “digs”.
I keep several worm bins going all the time and love to give away homemade worm systems to excited families. Red wigglers are probably the easiest pet to take care of. You can leave them for weeks and come back to find premium soil amendment for your garden – or more bait for fishing!
Which plants may benefit from worm castings?
All plants will benefit from worm castings. Even though the ratio of nitrogen, phosphorus and potassium are much lower than other materials, the nutrients are both fast and slow release. In my own garden, I add worm castings to my homemade container soil and always start my tomato seedlings out right with an initial dose of castings in the planting holes plus liquid feeds throughout growth.
Combine worm castings with…
Sometimes castings come mixed with other ingredients such as rock dust, peat moss, pumice and oyster shell lime. I like to use straight castings so that I have the freedom to apply them as I wish: amend my soil before planting, apply soil drenches throughout growth, or spray on leaves for nutrition and pest management.
Worm castings are not considered a significant source of nitrogen. Therefore if you’re growing vegetables that are nitrogen-hogs, pair castings with weed tea, alfalfa pellets or fish ingredients.
I could go on and on but will cut to the chase and give you my favorite ways to use worm castings in the garden.
Worm Castings Quick Tips
- Worm castings contain chitin, a protein-based lining that is food for beneficial soil bacteria.
- Worms love rabbit droppings. If you keep rabbits, consider placing your worm bins under their cages. Just be aware that manure should be fully composted and aged (or added according to the 120/90 day rule) to be applied to edible plants during growth. See the Manures section for details.
- Use worm castings that are finished. Unfinished vermicompost can contain bacteria that could damage your plants. The liquid that drains from a worm bin during active composition is usually not a worm tea. It is leachate much like the toxic runoff from a landfill.
Check out the Worm Composting FORUM for recipes using worm castings! Join in or just browse.