Organic Lawn Fertilization with Worm Castings & Tea

Fertilizing your lawn using worm castings is non-toxic and money-saving. Keeping a vermicomposting bin results in free organic worm castings. By feeding your kitchen and garden scraps to Red Worms, you will develop a supply of dark, organic fertilizer. You can make Worm Tea or apply castings directly. Using worm castings on your lawn is easy, economical, and good for the environment.

In just one day, you can turn the castings into Worm Tea and spray them on the lawn. Applying raw worm castings directly treats and feeds the lawn in a slower time-released way. Worm castings cannot chemically “burn” your lawn. Over-using an organic fertilizer like worm castings is almost impossible. You can use one method or both.

How to Get Worm Castings

Worm castings is a polite word for “worm poop.” Worms eat organic material, add valuable microbes, and excrete a dark, crumbly material called “castings.” After a few months or more, the worm bin will have a supply of castings you can harvest. Here are instructions for harvesting worm castings.

Making worm tea requires a relatively small amount of castings. If you plan on applying worm castings directly, you may need to wait until you have a good supply of castings or increase the size of your composting program.

Apply Worm Castings to Your Lawn

There is a hassle-factor with applying worm castings directly to the lawn. At the small and medium scale, finding a spreader can be challenging. The smaller spreaders tend to clog. This means frequent stops to unclog the nozzle. The larger PTO spreaders are better than the less-expensive spreaders. Golf courses, farmers, and institutions have professional-grade spreaders and tractors that do a better job.

You should screen the worm castings before putting them into a spreader. Screening removes sticks, worms, and debris, and breaks the compost into smaller particles. See instructions for making a screen.

Experiment with quantity. You will need at least 5 lb of castings for every 100 square feet of lawn.

Make Worm Tea

Prepare a batch of worm tea the day before you need it. To make 10 gallons of the tea, you will need:

• 1 lb worm castings
• A clean old sock without holes
• 2 tablespoons of molasses or corn syrup
• A 5-gallon bucket
• 10 gallons of dechlorinated water
• An aquarium bubbler with hoses

Dechlorinated water could be rain water. Or, use tap water – but if your tap water is chlorinated, let it sit overnight. Sitting overnight releases the chlorine molecules harmlessly into the air.

If you have a large lawn, this recipe scales up. The source of oxygen – the aquarium bubbler – might not be powerful enough for large quantities. Look online for a worm tea maker, or adapt a device that blows air. The blower will need to run continuously for 24 hours; pick something designed for this.

The purpose of adding air is to encourage the growth of friendly aerobic bacteria. Also, the air helps prevent dangerous anaerobic microorganisms from growing. The air should break the surface of the water.

The molasses or corn syrup provide sucrose. Sugar nourishes the bacteria and helps it grow.

Making worm tea is best done at room temperature, such as around 70 degrees — not out in the sun. Directions:

1. Put the worm castings into the sock and tie the top in a knot.
2. Place the full sock in the 5-gallon bucket of dechlorinated water.
3. Add 2 TBS molasses or corn syrup.
4. Drop in the bubbler and turn it on.
5. Let the bubbler run for 24 hours.
6. Remove sockful of worm castings.
7. Dilute the resulting mixture with 5 gallons of dechlorinated water.
8. Place the worm tea into a sprayer and apply to the lawn.

For smaller lawns, you can get away with a large watering can instead of a sprayer.

If the worm tea has too much sediment, strain it. You will know it needs straining if it clogs the nozzle.

Spray the worm tea on your lawn that day. The microorganism count will be at its highest. Best to spray in the early morning or late afternoon.

You should apply worm tea in early spring. If you are adding raw castings, add them first, then spray worm tea. Repeat the worm tea treatment once a month throughout the growing season until fall.

Do not allow pets to drink worm tea.

Worms Help Your Lawn

Did you know that European Night Crawlers (Super Reds) are excellent for your lawn? Release them on the lawn and they will dig in. They provide aeration and fertilizer. You can order Super Reds from Uncle Jim’s Worm Farm.

Worm castings are an economical, chemical-free method for feeding your lawn. Uncle Jim’s Worm Farm has completed compost, as well as high-quality Red Composting Worms for generating your own compost. We also carry a selection of tray-based composters for easy harvesting.