How to use Worm Castings
Comprehensive Guide to Using Worm Castings in Gardening
General Planting
- Before planting seeds or seedlings, evenly spread 1 gallon of castings per 30 sq. ft. of garden area.
- Work the castings 2" deep into the garden soil.
- Thoroughly saturate with water to flush the microorganisms and minerals into the garden soil.
Potting Mix
- Use 1 part earthworm castings to 3 parts soil.
- Alternatively, use up to 40% castings with good results, though lower concentrations are very effective.
Potted Plants
- Add 1-2 inches of earthworm castings to the top of the soil.
- Mix in carefully, taking care not to damage shallow roots.
- Water thoroughly.
- Repeat every 2-3 months.
Transplanting Seedlings / Potted Plants
- Dig a hole 3 times the size of the potted plant or seedling.
- Put one large handful of worm castings into the hole.
- For plants in non-plant able pots:
- Remove the plant from its container.
- Place the plant on the castings at the bottom of the hole.
- For plants in plant able pots:
- Simply place the plant on the castings at the bottom of the hole.
- Fill the remainder of the hole with garden soil mixed with worm castings.
- Water thoroughly.
Vegetables and Annual Flowers
- Line furrows and plant holes with 2" of earthworm castings before placing seeds and plants.
- Cover seeds and plant roots with soil.
- Side dress during growing seasons:
- Apply 1/2 cup per plant or 1 cup per linear foot of row once every 2 months.
- For larger growers: Use 60-100 lbs per 100ft row, or 7-15 tons per acre.
- Generally, vegetable plants need only one application per growing season.
Roses, Trees, Shrubs, and Berries
New Plantings
- Mix 1 part earthworm castings to 3 parts soil.
- Surround newly dug hole with this mixture.
- Spread roots over a mound of the mix in the hole and cover.
Established Roses
- Mix 4 cups of earthworm castings into soil 2-3 inches below the surface for each plant.
Lawns
New Lawns
- Apply 10 lbs of castings per 100 sq. ft. into the topsoil.
- Mix in grass seed and water well.
Established Lawns
- Top dress with 10 lbs of castings per 100 sq. ft.
Trees (fruit, citrus, nut, ornamental)
- Apply by top-dressing from the trunk to the edge of the drip line.
- For established trees:
- Top dress with 5 lb castings per 1-inch diameter of the tree.
- Apply two to three times a year.
It's important to apply during the spring blossoming period.