What to do with Worm Castings | 7 Ideas for Amazing Plants

Worm castings are perfect for your garden and can be used to improve potting soil, prepare your garden bed for vegetables or mixed into water and be fed to your plants. Worm castings will contain all of the nutrients from the broken down food scraps you fed to your worms. They also contain lots of soil bacteria which is perfect for improving your yard soil.

This article will explore 7 simple ideas for using worm castings in your garden to boost plant growth and improve soil.

1. Sprinkle worm castings around established shrubs

The simplest thing you can do with worm castings is to sprinkle them around established plants. These could be shrubs, flowering annuals, established trees or even vegetables. Simply scoop a small amount of worm castings out with a small trowel. Sprinkle it on top of mulch or rake back the mulch so the castings make direct contact with the soil.

Covering the casting with mulch will keep them moist for longer and keep the soli bacteria alive. You can water the worm castings after applying them to allow the nutrients to flow down to the plant roots.

Once your plants have established, sprinkle worm castings around their root base.

2. Mix worm castings through your vegetable garden at the end of the season

Improve your vegetable garden soil after your vegetables have finished growing at the end of summer or at the start of spring. Remove old vegetables like tomatoes, peppers and cucumbers. These plants use up a lot of nutrients as they grow and your soil will need these replaced.

Gently mix through some worm castings through your vegetable garden soil. You only need a small amount for your garden, just a handful per square foot. Add some extra cow manure and compost and let the ingredients settle in for 2-4 weeks before replanting. Protect the soil with mulch until you are ready to plant.

Sprinkle worm castings around your vegetable garden. They are great for tomatoes.

3. Add worm castings to potting soil

Worm castings can be mixed through potting soil before repotting new plants. Potting soil can be improved by mixing the nutrients rich worm castings through before planting. Worm castings will help the soil to retain moisture for longer and help to improve the soil bacteria balance.

You can also sieve the worm castings and mix up to 1/3 with some seed raising mix. Add some perlite and you will have the perfect mix for raising cuttings, seeds or seedlings.

4. Add worm castings to the hole when planting new plants in your yard

Before planting new trees or shrubs in your yard you can mix through worm castings down the bottom of the new hole for your plant. Dig the hole to the size of your new plant and add a small spade full of worm castings to the bottom of the hole. Gently mix the worm castings through with gloved hands or your spade.

Add worm castings to your soil when planting new herbs, vegetables or flowers.

5. Mix worm castings with water and add to plants

Another great way to use worm castings in your garden is to mix them with water first. Fill a large watering can with water and add a small scoop of worm castings. Make sure you take the end off your watering can so that the larger pieces can flow out.

Water your plants at the base of the roots to feed and water them at the same time. The nutrients and soil bacteria will be washed down to your plant roots to feed them. You only need a small amount to help your plants grow. Worm castings are a mild fertilizer that you can add to your plant each month over the warmer months.

Add a small amount of worm castings to your water can and water it onto your plants.

6. Improve soil in raised garden beds

Worm castings are a great ingredient to mix through raised garden beds to improve the soil. Raised garden beds filled with good quality soil will benefit from the added worm castings. They will add organic matter, nutrients and soil bacteria. This will give your plants the best chance of growing strong.

You can also sprinkle worm castings around the top of the soil once your plants have been growing. Cover the worm castings with mulch and water them in well.

Mix worm castings through the soil when filling your raised garden bed.

7. Top dress citrus trees with worm castings

Worm castings are the perfect ingredient for top dressing citrus trees. Mix worm castings with compost and rake it over the root zone of your citrus trees in spring. This will help to prevent weeds, protect the roots and feed the plant.

Rake back the old mulch first so the top dressing can lay straight onto the soil. Take care not to disturb the soil when raking the mulch back so that the top feeder roots of the tree are not damaged.

Top dress citrus trees with a small amount of worm castings with compost and rake it over the soil.

What to do with Worm Castings | Summary

Worm castings are a great ingredient for your garden that you can make for free at home or buy from garden centers. Worm castings made at home will contain all of the broken down ingredients from the food scraps and worm bedding you feed to your worms. The range of nutrients will reflect the food that you feed your worms.

Worm castings will help the soil to hold water for longer, feed your plants, improve the soil bacterial balance and increase the organic matter in the soil. Worm castings can be harvested from your worm farm around every 9 months and used in your garden.

For more on harvesting worm farm castings, check out my previous article here: