Gardening with Gold

Sharon Chupak
Special to the Adams County Master Gardener Program

Treat your plants to the many benefits of earthworm castings. Often referred to in gardening circles as "black gold," they provide higher yields of more vibrant, longer lasting blooms and better quality fruits, greener, fuller plants with stronger, sturdier stems and healthier, deeper root systems. Overall, they provide healthier plants that are less susceptible to disease and drought.

Earthworm castings (worm excretions), which resemble coffee grounds in color, size and texture, are a premium, natural alternative to chemical-based fertilizers. Being all natural, nontoxic and chemical-free, castings appeal to the environmentally conscious, organic-minded gardeners and those who have children or pets. Regular use improves soil quality, increases the amount of humus and lessens nutrient runoff.

Quality casts, produced consistently, provide the nutrients indoor and outdoor plants need to thrive. They are an excellent source of nitrogen without the fear of burning the plants, making it a "must have" product for gardening with children. Other important nutrients found in castings include iron, potassium, sulfur, phosphorus, calcium and magnesium. Because castings are nutrient rich and have high microbial activity, it takes only a small amount of product to achieve noticeable results. Castings truly are nature's purest and most effective form of plant food and typically outperform most commercial fertilizers.

Microbial activity is where all the secrets of success are stored and is the focus of ongoing research. Studies have shown that while the earthworms derive their nutrition from microorganisms present in the organic matter they eat, many more microorganisms are present in their casts. As the worms digest their food, it is broken down and implanted with additional microorganisms which facilitate the cycling of nutrients from organic matter and their conversion into forms usable to the plants.

Worm castings provide a natural time-release of these plant nutrients, in part, because they are excreted in a mucus membrane that hardens on contact with air. Over time, the mucus membrane breaks down, slowly releasing the nutrients to your plants. In general, compared to chemical fertilizers, the nutrients found in castings are in a much more stable form and water soluble, which make them less susceptible to immediate nutrient leaching and readily available to plants.

Castings are made up of a high percentage of humus. Humus, which is light and fluffy, helps aerate the soil, allowing more oxygen and water to get to your plants' root systems. It also allows the castings to hold two to three times their weight in water, so potted plants will stay damp, requiring less water less often, to prevent drying out between waterings.

If you have hanging baskets or potted plants on your patio or porch, you want to give castings a try. Because of their natural, time-release of nutrients and their ability to hold moisture, they are great for planting at cottages or summer homes, town beautification gardens or cemeteries where plants get little care after planting

Worm castings are very versatile and can safely be used on houseplants, annuals, perennials, herbs, vegetables, roses, trees, shrubs and lawns by home gardeners and commercial landscapers, nurseries and growers alike. For lawn care, spread 10 pounds of pure earthworm castings for every 100 square feet of new or existing lawn and water well. They should be applied early each season. When planting annuals, vegetables or herbs, just line each new plant hole with an inch of castings. Then feed monthly for the rest of the season by sprinkling castings around the base of the plant. For potted plants, indoor or outdoor, just add one tablespoon monthly for every two to three inches of pot and water as needed.

Earthworm castings should be added to your favorite potting mix when planting. Rates vary depending on the plant. You can help enhance the composting process in your bin or turner by simply sprinkling a thin layer of castings over your compost before adding new material.

If you have never tried castings, it is fun to experiment by using the products you now use on half your plants and worm castings on the other half. See the results for yourself in your own flower beds or vegetable gardens.

The Master Gardeners of Adams County are using worm castings in this year's Trial Garden where you can see for yourself what results this "black gold" produces in our area. Stop by anytime or plan to attend one of our Garden Walks. Evening Trial Garden Walks take place on the 1st and 3rd Wednesdays and Native Garden Walks take place on the 2nd and 4th Wednesdays at 6:30 p.m. for the rest of the summer. Meet a Master Gardener for each tour at the Ag building.

Worm castings come in a variety of sizes and forms. For more information, contact or call 877-583-6367. Worm castings can be purchased locally at Hanover Home & Garden, Hanover; Buttercup Farm Market, Abbottstown; Cross Creek Farm; Glen Rock; or Poplar Hollow Farm; Glenville.

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