Premium, Bulk Worm Castings



Bulk Worm Castings for Sale

The prices above do NOT include shipping (via LTL freight) to your location. We will contact you within 24 hours with the LTL freight options and costs.

Premium, lab-tested bulk worm castings in 1, 1.5 and 2 yard FIBC super sacks. For use in soil mixes and amendments, farm/garden, and grow operations. Clients include city compost operations, soil mixing companies, organic gardening centers, and other professional growers.

We do not add filler of any kind to our worm castings so the bulk worm castings super sacks consist of worm castings and small amounts of other organic matter (and sometimes a few worms and cocoons!).

Our bulk worm castings' clients include city compost operations, soil mixing companies, organic gardening centers, and other professional operations. The worm castings are used as a natural fertilizer and soil amendment for plants and also in mixes for commercial and home-based gardens, cannabis growers, and other agriculture/horticulture systems.

For pick-up in the Austin area or full truckload orders (20 yards or more), please reach out to us at and we're happy to provide a quote.

Our Process

Brothers Worm Farm’s bulk worm castings are produced from our red wiggler and compost earthworms. We have implemented a standardized and repeatable approach to breeding earthworms and producing worm castings to ensure consistent and quality castings. Our approach includes carefully optimizing the pH and moisture of the bedding we breed earthworms in. In addition, our worms are fed a diverse diet of composted fruits, vegetables, and carbon-sources diverted from landfills via Austin’s Zero Waste Landfill initiative. The end result is a dark and nutrient-rich product ideal for growing plants, shrubs, vines, fruits, trees, herbs and vegetables.

In addition, test results from a national independent soil laboratory show a casting rich in organic matter, soluble salts, important bio-available nutrients, and fungal and biological feeders (including beneficial flagellates, nematodes, fungi, and protozoa). This composition helps create healthy soil conditions for optimal seed germination and plant growth.

How to Use Worm Castings

Worm castings are a versatile soil amendment that can benefit houseplants, flower plants, vegetables, herbs, annuals, perennials, vines, and fruit plants. Castings can be used indoor or outdoor in potted plants, raised or in-ground gardens, or applied directly to a yard or growing area. Worm castings are an all-natural substitute for toxic fertilizers and messy compost and manures.

For more details, check out our post on how to use castings in your new or existing houseplants or garden.

Worm Castings Frequently Asked Questions (FAQs)

1) How much do bulk worm castings super sacks weigh?

1 yard of worm castings can weigh anywhere from 800 lbs to 1600 lbs,. The difference is based on moisture/water content in the castings as well as the density of the castings (which is driven by bedding and feedstocks). Our bulk worm castings weigh ~1,300 pounds per cubic yard. When buying in bulk it’s important to buy according to volume instead of weight (since 1 yard of castings from 1 supplier can weigh 1,000 lbs and a cubic yard from another seller can weigh 1,600 lbs).

2) Do you have lab tests?

Yes - please see our castings lab tests here.

3) How will the bulk worm castings ship?

We’ll ship the bulk worm castings to you using a LTL freight carrier. The bulk super sacks will be palletized and require a forklift or loading dock for unloading.

4) Do you have bulk worm castings in stock right now?


5) When will the worm castings ship after I order?

Once an order is received we will reach out to confirm your order and availability of a forklift or loading dock. We will then schedule a freight carrier to pick-up your bulk worm castings order. The process from order to pick-up will take 3-7 days. Once picked-up, the bulk worm castings will be delivered to you within 3-5 days (depending on location and carrier transit times). We will provide tracking information (when available) so you can track the status of your order.

We're service-obsessed and committed to making your order - and vermicomposting journey - a great experience.  Have questions? Email us at and we're happy to help!