worm castings

How To Use Worm Castings In The Garden

Ask a gardener or a farmer what they think of worms and you’ll probably get a lot of positive feedback. Why? Because what comes out the backside of a woman is gardening gold! I’m talking, of course, about worm castings. “Castings” are the term applied to the manure that comes from a worm. It’s packed with nutrients that your garden plants crave and doesn’t stink, unlike manure from larger animals. Want to learn how to use worm castings in your garden? Read on!

How to use worm castings in your garden

There are four common ways that worm castings are used in the garden. These include simply spreading it on top of your soil, giving a bit more during important, high-growth periods, making tea from your worm castings, and adding it to your compost. There’s no wrong way to do it, really, but these are the most common ways.

Spread worm castings to the top of the soil

When it comes to applying worm castings, you don’t have to do any fancy mulching or tilling or anything like that. Your best practice is to simply sprinkle about 1/2 cup of worm poop on 100 square feet. A 10×10 foot space only needs at most 1/2 of a cup. You can evenly distribute it on the soil, but another option is to focus it near the base of each of the plants in your garden.

Spreading castings right at the base of your plants will help ensure that your plants get the maximum benefit from the castings, but it is worth noting that when amending your garden soil, the best long-term practice is to amend all of the soil, not just directly where you’ve planted.

Apply more during budding and fruiting

When your plants are going through budding, flowering, and fruiting, they need more nutrients that your worm castings can provide. If, for example, you’ve fertilized your new crop of tomatoes with worm castings and they’re getting ready to flower and fruit, spread another layer just to give your plants that little bit of extra nutritional goodness.

Be careful not to overdo it, though. Worm castings really only need to be spread every two to three months. And remember: a little bit goes a long way! You only need about 1/2 cup of castings for a 10×10 foot space.

Make worm casting tea

Another option for applying worm castings to your garden is to make a “tea.” Definitely not the kind you want to drink, but it’s fundamentally the same concept. Simply add 2 cups of worm castings to a 5-gallon bucket of water and allow it to sit overnight. You can put the castings in a cloth sack, or even an old sock, for easy cleanup later. You can also just mix them in directly – they will most likely dissolve completely.

You’ll know your tea is ready when the water has taken on a darker, tea-like appearance. Now you can water your plants with this tea! A huge benefit to using worm casting tea is that, as the water soaks into the ground, it brings more of the nutrients with it. When applying castings to the top of the soil, it takes a bit of time for it to break down and leech its nutrients into the soil. Tea gets it in there right away.

Read More: How to make worm casting tea

Add it to your compost

If the whole concept of messing with worm poop kind of grosses you out, no worries! Did you know you can compost it too? Every 2-3 months, simply layer about a one-eighth inch layer of castings over your compost. You can mix it in a bit too if you want. The castings will break down and mix in with the rich soil being created in your compost heap. No need to directly handle the castings!

Thomas Nelson
Gardening Expert
Hi! I'm Thomas, one of the founders of The Garden Magazine. I come from a long line of gardeners who used the art of gardening as a way to live long, healthy lives. I'm here to share my knowledge of gardening with the world!