Worm Castings For Growing Cannabis

Worm Castings For Growing Cannabis

In some ways, worm castings are the best-kept secret of veteran marijuana growers. They are often overlooked when cannabis growers are looking for ways to improve the health of their plants, get higher yields and provide organic nutrition to their plants.

Worm castings, or worm poop, will enhance the health of cannabis plants and provide long-term nutrition without harmful chemicals.

According to Marijuana Venture Magazine, Worm castings are “the secret to great soil.”

Using Worm Castings to Grow Marijuana

Now that recreational weed is legal in Arizona, there are many hobbyists looking to grow their own at home and large-scale farming operations growing to meet the massive increase in demand in the state. Worm castings are perfectly positioned to be the soil supplement that these growers of all sizes need.


Benefits of Worm Castings

Worm castings are the soil amendment for all types of plants, but they are specifically great for marijuana growers who want to grow organically.

Extensive University testing has been performed by Ohio State, Cornell University, UC Davis and the Australian SIRO to prove the worth of worm castings. The tests have shown improved flower size, bloom quantity, quality and color. Fruit and vegetable tests have resulted in yield improvements from 57% to over 200% as well as improvement in taste and appearance

A study by Cornell University found castings not only improve yield, they protect plants from pests.

The beneficial nutrients found in castings are absorbed easily and immediately by plants (unlike chemical fertilizers and manure) and they will never burn plants.

There is a growing body of research demonstrating castings aid in the suppression of pests and serve as a natural, organic protection for plants.

Applying Worm Castings to Plants and Soil

The beauty of worm castings is the ease and variety in which they can be applied to plants

Soil Amendment

Many growers use a mix of 25% earthworm castings to 75% soil. That’s typically enough to make a big difference for the plants.

In reality, the ratio isn’t an exact science and adding even a small amount of worm castings to your soil will greatly improve their health.

Our castings can be sprinkled on top of already established plants, or mixed in the soil during planting. There will be a noticeable difference within the first few days of use.


A tea can be made from the castings resulting in a 100% organic spray that improves nutrient absorption. It will NOT burn your plants. This easily absorbed water-soluble mixture can be sprayed directly onto plants for immediate absorption or applied once a month while watering.

We recommend watering down our highly concentrated casting tea 10:1.

The casting tea we make at Inch by Inch AZ has a beneficial blend of bat guano, compost, and castings. The tea must be used within 48 hours of purchase.

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