There are many uses for worm castings in gardening. The castings have a nice even consistency and you should have more than you need. Depending on the worms' diet, castings can contain up to eleven times the amount of nitrogen, potassium and phosphorous available in soil unworked by worms.
Use castings to enrich potting soil. The sheating property of the worm castings causes them to clump together. Add about one-quarter castings to three-quarters of your regular soil mix. If you exceed this proportion, the potting soil will become hard packed with cement-like consistency. Seeds can be started in pots or trays with a mixture of castings and your favorite potting soil.
For transplanting seedlings, line the bottom of a row with castings to a depth of two inches, working the castings into the soil before planting. After planting you will see positive results in your seedlings, with little, if any, transplant shock.
To make a wonderful liquid fertilizer, often referred to as "worm tea," tie one cup of castings in an old sock or stocking. Soak in one gallon of water overnight or a few days and use as you would a commercial brand of fertilizer. It can be stored up to two months in a capped container. Use as you like on your house plants. Worm tea also can be used as a foliar spray on both your indoor and outdoor plants.
Mature shrubs, ornamental and fruit trees all benefit from worm castings. Put the castings two to three inches from the base of the plant and in a circular pattern continue out to the drip line. Nutrients in the castings are water soluble, so watering and working the castings into the soil immediately after application will result in healthier plants. This fertilizing treatment can be repeated throughout the season; something you would have done with costly manufactured chemicals in the past.
To use castings on your lawn, pre-water the area you will treat. Broadcast the castings just like any commercial fertilizer. Re-water the lawn afterward to begin leaching nutrients into the root zone.
You can now use your worm castings instead of commercial fertilizers. Plus, you have made a herd of worms a very happy home.