How to Add Worm Castings to Your Garden and Lawn

Composting with worms results in highly nutritious worm castings. Your lawn and garden need nutrients to grow. Therefore, putting worm castings in the soil will help your plants grow strong. How do you harvest worm castings? Where can you apply them?

Worm castings are also known as worm poop. Vermicomposting, or composting with worms, means maintaining a special bin filled with bedding and composting worms. We recommend Red Worms for most composting projects. If you also want fishing worms, then European Night Crawlers can do double-duty. Just feed your kitchen scraps and garden waste to the composting worms. They will eat through the organic material and produce fluffy, dark worm castings. Worm castings are also called “black gold” because they are the perfect soil amendment. Vermicomposting reduces waste and makes excellent organic fertilizer.

Follow these steps to grow lush gardens and lawns.

How to Harvest Worm Castings

It is quite easy to retrieve worm castings from the vermicomposting bin. With tray-based composters, harvest the dark material from the lower trays. Should you find a few worms, move them to the top tray. Then, place the contents of the lower trays into buckets, wheelbarrow, or bags. With other kinds of vermicomposting bins, we suggest you remove finished compost from the bottom. See our article about harvesting compost for more details.

You may find sticks, fruit pits, rocks, partial avocado skins, etc. in the trays or in the containers. We strongly urge you to remove these items before you apply the compost to your gardens. These items form a barrier and impede the flow of water in the soil. Some people sort the compost by hand. For the more squeamish, we suggest using a screen as a sieve. Screens can be purchased at hardware stores or built at home. Please refer to our article about screening compost.

The fresher the humus, the more active the microbes. Removed from the worm’s environment, soil-friendly bacteria begins to die. However, older humus still provides nutrients that are good for the soil. Whatever compost you do not use the first time, save for next time.

The Next Step: Prepping the Soil

Bring a rake, a hoe, and other equipment as well as your compost outdoors. Whatever area you select to start planting, make sure to clean the topsoil from rocks, roots, leaves, sticks, and any other debris. This will help rain to flow freely.

Now It Is Time for Planting!

New Shrubs, Trees, and Plants

We suggest you dig a hole larger than the recommended size. With the soil you removed, clean through and remove any debris that would impede rainwater flow. Then add humus or finished compost to the soil. Fill the hole with the mixture up to the recommended size. After you place the plant in the hole, pour in the rest of the mixture and lightly tamp it down. Water thoroughly.

Vegetable Gardens

Use a garden fork or rototiller to expose the soft soil underneath. Layer it with a half-inch to an inch of finished compost and dig in to mix. Then, plant the seeds. The nutrients in the compost will nourish the seeds. Certain crops can be replanted. Simply re-apply the compost.

Existing Plants (Trees, Shrubs, and Flower Plants)

Place the finished compost around the stems. Rain will wash nutrients to the roots.

Bulbs

Layer compost and topsoil before you plant bulbs. Water well.

Lawns

Worm castings are ideal for nourishing lawns, especially bare patches. Just dig in an inch of compost and then top it off with grass seed. Otherwise, we suggest five pounds of compost per 100 square feet. Apply a thin layer directly to the lawn for optimal results. Another option is worm tea. Refer to our article on how to make worm tea from worm castings.

Uncle Jim’s Worm Farm is the country’s leading supplier of composting worms. In rural Pennsylvania, we grow and sell live Red Worms for composting and Super Reds (European Night Crawlers) for composting, aeration, and bait. Feel free to browse our website for equipment to start your own vermicomposting project. And visit our blog for more tips on vermicomposting from A to Z.