Frequently Asked Questions

What are worm castings?
The castings (otherwise known as excreta or vermicompost) produced by worms are the purest and most perfect form of plant food. In addition to containing unusually high populations of beneficial microorganisms crucial to healthy root systems, castings also naturally aerate the soil, retain high moisture levels, and release nutrients slowly over time to meet your plants needs.

How are castings produced?
There are thousands of earthworm farmers across America. In one day, these "compost-worms" are able to transform their own weight in organic matter into this premium quality soil enhancer. The worms reduce the volume of material by half, leaving this highly concentrated and powerful soil amendment behind. New worm food is added in thin layers periodically, while the castings settle to the bottom of the pile. After a few months, the worms are separated from the castings, screened, carefully checked for quality, then bagged by hand.

What results should I expect?
Castings can naturally improve the look and health of your plants, stimulate flowering and fruiting, and produce larger harvests. Studies have shown several types of pests and diseases being eliminated naturally. As an organic product, these benefits can all be achieved without fear of burning your plants, or harming the environment.

Why are castings better than good compost?
The belly of an earthworm infuses regular compost with beneficial organisms, while further transforming the nutrients into an odorless form more readily useable by plants. Castings can even be mixed with mulch to give your plants what they've been craving. In nature, animal waste and decaying plant material are worm food, not plant food. Worms are the most natural producers of plant food!

What other benefits can I expect?
Worm castings have additional advantages over other soils, including traditional composts. When ordinary compost is placed on the ground to enrich plants, the available nutrients are quickly leached into the soil as soon as rainfall or sprinkler irrigation systems are turned on. Vermicompost provides a time-released benefit, slowly nurturing the plants over a greater length of time.

Worm castings contain plant nutrients encased in mucus membranes secreted by the earthworms. Castings dissolve slowly rather than allowing immediate nutrient leaching. The product has excellent soil structure, porosity, aeration, and water retention capabilities. It can insulate plant roots from extreme temperatures, reduce erosion and control weeds.

What does humus do for my plants?
The humus contained in Soil Secret helps soil particles form into clusters, creating channels for the passage of air, water, and roots, while improving the capacity of the soil to hold water. When normal topsoil dries out, it has a very dense structure, which prohibits root growth. When the soil receives rain after a dry period, the water will run off rather than be absorbed. Castings, with their clustered structure, do not form as dense a structure when they dry, and the passages for air, water and roots remain intact. Humic acid, present in humus, provides binding sites for plant nutrients, but also releases them to the plants upon demand. Humus is believed to aid in the prevention of harmful plant pathogens, fungi, nematodes, and bacteria.

Other benefits of humus include:

1. Acting as a growth stimulator. "Experiments on wheat, barley, potatoes, grapes, tomatoes, beets, and other crops show that even in very low concentrations, humic acids (contained in castings) act to stimulate plant growth. Tests to determine just how humic acids work revealed that they are in an ironically dispersed state. In this form they are readily assimilated by the plants as a nutrient, over and above any normal mineral nutrition that plants get." --(The Rodale Book of Composting, 1992, p.26)
2. Acting as a "buffer." Humus can help plants overcome soil pH levels that are too high or too low. An acid-loving plant can still do well in a somewhat alkaline soil (and vice-versa) if large enough quantities of humus are present. This is due to the way humus prevents extreme pH levels from rendering soil nutrients "unavailable" to the plants.
3. Capturing toxins that are present in the soil. Humus (which is organic matter) has a high capacity to fix heavy metals in materials such as sewage sludge, farmyard manures, crop residues and peat, preventing plants from "taking up" more of these compounds than they need, then later releasing them when they are required.

What have experts had to say about worm castings?
“Earthworm castings are the best imaginable potting soil for greenhouses or houseplants, as well as gardening and farming. It will not burn even the most delicate plants and all nutrients are water-soluble, making it an immediate plant food. Earthworm castings, in addition to their use as potting soil, can be used as a planting soil for trees, vegetables, shrubs, and flowers. They may be used as mulch so that the minerals leach directly into the ground when watered. The effects of earthworm castings used in any of these ways are immediately visible. The make plants grow fast and strong. Nematodes and diseases will not ruin gardens or plants if the soil is rich enough for them to grow fast. It is the weak plant in poor soil that is destroyed by nematodes and diseases.”

R.E. Gaddie and D.E. Douglas, Earthworms for Ecology and Profit
Volume I “Scientific Earthworm Farming.” 1975, p.175

“Castings contain: 5 times the available nitrogen, 7 times the available potash and 1 ½ times more calcium than that found in 15 cm of good top soil. Therefore, castings are supplied with available nutrients. The nutrients are also water soluble and immediately available to plant life. You will find that most potting soils have nutrient life of 2-5 days, where worm castings will last up to 6 times as long as other types of potting soils. You will need 5 times as much potting soil to do the same job as the worm castings. So, in the long run, worm castings are much cheaper and do a much better job. Also, castings hold 2-3 times their weight in water. That means you water less and the pot will stay damper for a longer period. Worm castings will not burn your plants; unlike using any fresh raw manures (cow, horse, etc…) which can burn root systems if it is not applied properly. The advantage of using castings is the manure passes through the worms’ digestive system producing rich organic plant food and a slow releasing fertilizer that allows for better growth.”

Wormwatch, Education Department of South Australia, 1992 p 35.

“A worm casting (also known as worm cast or vermicast) is a biologically active mound containing thousands of bacteria, enzymes, and remnants of plant and animal manures that were not digested by the earthworm. The composting process continues after a worm casting has been deposited. In fact, the bacterial population of a cast is much greater than the bacterial population of either ingested soil, or the earthworm’s gut. An important component of the dark mass is humus. Humus is a complicated material formed during the breakdown of organic matter. One of its components, humic acid, provides many binding sites for plant nutrients, such as calcium, iron, potassium, sulfur and phosphorus. These nutrients are stored in the humic acid molecule in a form readily available to plants, and are released when the plant require them.”

Mary Appelhof, Worm Eat My Garbage, 1982, p 68.