How much worm castings should I use?

For most garden beds, incorporate worm castings at 5–20% by volume into the top few inches of soil. For container plants, mix 10–25% into potting soil. Smaller amounts can be applied as a top dressing during the growing season.

Can worm castings burn plants?

No. Properly matured worm castings are low in soluble salts and release nutrients gradually, making them safe for seedlings, transplants, and established plants.

Are worm castings better than compost?

Worm castings are often more biologically concentrated than traditional compost, typically containing higher microbial activity and more plant-available nutrients.

Do worm castings replace fertilizer?

Worm castings improve soil biology and nutrient availability. They may reduce reliance on synthetic fertilizers but are commonly integrated into a broader soil fertility program.

Worm Castings Archives

February Gardening Guide for Beginners: Using Vermicompost in the SF Bay Area

By Delta Worms | January 28, 2026

February in the San Francisco Bay Area is a transition month, and it’s an ideal time to start improving your soil with vermicompost for SF Bay Area gardens. As days grow longer and soils begin to warm, many gardeners are preparing for early spring planting. For new gardeners and first-time users of DW Vermicompost (vermicompost…

Buy Worm Castings Online: What to Know Before You Order

By Delta Worms | January 14, 2026

If you’re looking to buy worm castings online, mail order options make it easy to improve soil health when local sources aren’t available. Whether you’re gardening at home, growing houseplants, or amending container soil, mail order worm castings make it easy to access a high-quality natural soil amendment. Not all vermicompost is the same, though.…

Where to get DW Vermicompost – East Contra Costa County

By Delta Worms | July 3, 2025

Hey East Contra Costa County gardeners here’s where to get DW Vermicompost, locally. If you’ve been searching for local, high-quality vermicompost (worm castings) to supercharge your vegetable beds, flower gardens, or orchard soil — your search ends today. Because the rich soil behind our community’s thriving gardens has a secret ingredient… and it’s right here.…

What is Vermicast (Worm Castings) and Why Are They Amazing?

By Delta Worms | July 2, 2025

If you’ve ever wondered what worm castings are—or why gardeners talk about them like gold—you’re about to find out why this natural soil booster is one of the best things you can add to your garden. 🪱 So… What Are Worm Castings? Worm castings are the nutrient-rich waste produced by composting worms, most commonly red wigglers. As worms…

DW Vermicompost – Local Worm Castings

By Delta Worms | June 21, 2025

What is Vermicast? Vermicast, also known as worm castings or worm compost, is a nutrient-rich organic fertilizer produced by earthworms. It’s prized in gardening and farming for improving soil health and boosting plant growth. Here’s how to use it effectively: Vermicast Benefits Vermicast, also known as worm castings, is one of the most nutrient-rich and…