About Us

 Rainbow Farms Mealworm Fertilizer is 100% natural and 100% vegetarian approved for all garden edibles, plants, flowers, fruits and medical cannabis growing. Unlike other fertilizers bearing the “organic” label that carry second generation chemicals from antibiotics, growth hormones and steroids, Rainbow Farms Fertilizer contains no fillers or hormones, nor any composition elements from bone or blood meal, chicken meal or bat guano. Our mealworm castings additionally, have 15 natural micronutrients to replenish your soil and stimulate growth: Nitrogen. Phosphorus, Potash, Potassium, Copper, Calcium, Zinc, Manganese, Iron, Boron, Sulfate, Sodium, Molybdenum, Bicarbonate.  All natural, all organic.
The mealworms we use are fed a diet of wheat bran and raw carrots… a real Vegan diet! There are no impurities such as worm eggs, stones, weeds, straw or other debris or fillers ever found in our fertilizer. Rainbow Farms Fertilizer is 100% natural and truly organic.

 Mealworm castings (frass) have a natural NPK of 4-3-2 without chemical additives of any kind. Our patented development process converts the basic mealworm  castings to a powerful concentrated organic liquid fertilizer (not a tea) that when diluted up to ten-to-one is perfect for hydroponic growing, irrigation, drip lines and foliar spray – the new supercharger for organic growing!

Concerned with the dangerous chemicals used in growing medical cannabis/marijuana plants, we have developed our Cannabis Gro and Liquid Cannabis Gro  to insure that medical patients need not worry about chemical contamination when ingesting or inhaling medicine grown with our fertilizer.

We are a small eco-friendly company concerned with the health of all our customers.


Mealworms are used for scientific testing, school and lab projects, fishing, wild and pet bird food and in some countries a mealworm paste is considered a great protein enhanced  food source.

We now find that their droppings (castings, also called frass) is one of the best single-source all natural completely organic fertilizers made my Mother Nature herself.

Calling a mealworm a ‘worm’ is actually a misnomer—it is actually the larva stage of a darkling beetle (Tenebrio Molitor). Very similar to that of the butterfly: eggs hatch larva, which after 100 days pupate and become beetles, live two weeks to breed and start the circle of life again.

The mealworm derives its name from that fact that its favorite food happens to be wheat, oats and corn. In the wild it eats leaves, sticks and grass mostly.

Unlike the common earthworm (red wigglers mostly) which is farmed to produce fertilizer compost and fishing bait and are fed anything from table scraps, plant trimmings and garbage, the raising of mealworms is as close as you can get to an exact science: raised in a darkened, temperature and humidity controlled environment, they are fed a select diet of wheat bran and raw carrots—food that a Vegan would be proud of! Therefore, their excrement (castings) are as pure and natural a truly organic fertilizer with no chemicals or blends.

Many have found that Rainbow Farms Mealworm Fertilizer to be the best all natural, all organic all purpose fertilizer for your vegetable garden,

indoor and outside plants and flowers and even your lawn! Fast growing and safe—for your children and pets.

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Is a mix of original Rainbow Farms Fertilizer mealworm castings (NPK 4-3-2) and our patented time-release organic mealworm casting pellets (NPK 3-2-3) that our tests show stimulate fast and healthy grow without the need of artificial chemical growth elements.

  • Price: $10.00

LIQUID GRO - 32oz. organic foliar spray concentrate

Spray Concentrate

32oz. spray concentrate refill bottle that will make 1 gal. of foliar spray.

  • Price: $30.00

LIQUID GRO - Organic Cannabis Foliar Spray

LIQUID GRO - Organic Cannabis Foliar Spray

Growing medical marijuana as a medicine by professional growers or the patients themselves should always involve concerns about the fertilizer they use. While the package may clearly state “ORGANIC” in reality, many second generation...

  • Price: $15.00



(A 5 to 1 dilution of Rainbow Farms Liquid Fertilizer with non-chlorinated water) This special liquid formulation (not a tea) gives the plants and veggies organic, natural growth nutrients without the use of harmful chemicals. The results of...

  • Price: $9.95

Wet and Dry Cannabis Grow Team Special

~ Wet and Dry Cannabis Grow Team Special ~

~ Wet and Dry Cannabis Grow Team Special ~ ENOUGH ORGANIC FERTILIZER FOR 10 PLANTS! One bag of CANNABIS GRO 16 oz. Dry & Time Release One bottle of LIQUID GRO CONCENTRATE 16 oz. (makes up to 2 gallons of foliar spray) GRO TEAM SPECIAL ~ $20.

  • Price: $20.00

100% Natural 100% Organic


Our mealworms are hand-fed a special diet of wheat bran and raw carrots

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