What you need to know about worm castings

benefits of worm castings

Worm castings are how half a billion years of evolution has handled soil regeneration. It is much safer and more effective than harsh fertilizers that have been developed in the last half a century or so.

Worm castings are an exceptional natural fertilizer, offering a plethora of benefits for soil and plants. They improve soil structure, enhancing water retention and aeration, which is crucial for root growth.

Rich in essential nutrients and beneficial microbes, worm castings release nutrients slowly, ensuring a longer-lasting and more balanced nutrient supply. This helps in promoting healthier, more vigorous plant growth and increased yields.

Furthermore, the microbial activity in worm castings can help suppress soil-borne pathogens, reducing the need for chemical pesticides.

There’s a reason why worm castings are referred to as “black gold” or superfood for you plants, they have a proven track record of millions of years improving soil structure and plant growth.

where to use worm castings


Worm castings are a versatile soil amendment that can be beneficial across various gardening and landscaping practices. Their application extends beyond simple use in gardens or pots; they enrich the soil in indoor and outdoor settings alike.

Whether it’s revitalizing a worn-out lawn, boosting the health and yield of vegetable gardens, or ensuring the vibrant growth of flower beds, worm castings serve as a natural enhancer.

They’re also key in starting seeds off on the right foot, providing a nutrient-rich environment for germination and early growth. This adaptability makes them an indispensable tool for gardeners aiming for sustainable and natural cultivation methods.

Essentially, if it has roots and wants to grow, worm castings will help!

How to use worm castings

Because there is a wide variety of applications, the use cases of worm castings can vary as well. Here are some of the most common ways we see our worm castings being used.

Use CaseApplication & Amount to UseUse Frequency
Seed StartingIncorporate worm castings into your seed starting mix at a ratio of 1 part castings to 3 parts mix. This provides seeds with essential nutrients and beneficial microbes right from the start.Once at planting. Top dress according to instructions below.
Potting and Repotting HouseplantsWhen potting or repotting, create a mixture of worm castings and potting soil. A recommended ratio is between 25% to 50% worm castings to ensure your plants receive a balanced supply of nutrients and microbial benefits.Once during initial potting then again whenever repotting. Top dress according to instructions below.
Garden and Flower BedsBefore planting, spread a half-inch layer of worm castings over your garden or flower bed and work it into the top 6 to 8 inches of soil. This enriches the soil and promotes healthy plant growth.2-3 times per year. Once in early spring and again in summer and/or fall.
Vegetable GardensFor vegetable gardens, mix worm castings into the planting holes or rows at a rate of 1 cup per plant or 1 cup per linear foot of row. This method encourages strong root development and increased yield.Once at planting. Top dress according to instructions below from spring until harvest.
Lawn CarePreparation: Aerate your lawn to ensure better soil penetration.
Application: Spread worm castings evenly across the lawn. Use about 10 pounds per 100 square feet or adjust based on lawn condition and size.
Incorporation: Lightly rake the lawn to help the castings settle into the soil.
Watering: After application, water your lawn to help the worm castings integrate with the soil, delivering nutrients to the grass roots.
Once per year and when installing new grass.
Liquid Fertilizer (Worm Tea)To make worm tea, steep 1 cup of worm castings in a gallon of water for 24 hours, stirring occasionally. Use this tea to water your plants or spray on foliage for a quick nutrient boost.Can be applied every 2-4 weeks during the growing season. Adjust frequency based on plant response and growth stages.
Top DressingTo maintain nutrient levels and soil health, top-dress the soil around your plants with worm castings. Apply a quarter-inch layer around the base of each plantEvery 2-3 months during the growing season

how to store Worm castings

Because there are living microbes in the worm castings that are naturally balanced store worm castings in a dry place that is out of the sun.

If you buy our pink bag just make sure that the inside doesn’t get too wet and you should be good to store it pretty much anywhere.

frequently asked questions

what are worm castings?

Worm castings are the nutrient-rich waste produced by earthworms as they digest organic material.

How do worm castings benefit plants?

Worm castings benefit plants by providing a rich source of nutrients in a form that is easily accessible to plants. They improve soil structure, enhance moisture retention, and introduce beneficial microbes that aid in plant growth and health. This natural fertilizer slowly releases nutrients, ensuring a long-lasting, balanced supply without the risk of burning the plants, making it an excellent choice for boosting plant vitality and productivity.

Can worm castings burn plants?

No, worm castings will not burn plants. They are gentle on plants because they release nutrients slowly, ensuring plants receive a steady supply without the risk of nutrient overload that can lead to burning. This makes worm castings a safe and effective fertilizer for all types of plants.

How often should I apply worm castings to my garden?

It’s recommended to apply worm castings to your garden every 2-8 weeks during the growing season to continuously supply your plants with essential nutrients and to maintain soil health. This frequency can be adjusted based on plant response and specific gardening goals.

What is the difference between worm castings and compost?

Worm castings and compost differ primarily in their composition and nutrient content. Worm castings, produced by worms digesting natural material, are richer in nutrients, beneficial microbes, and enzymes. Compost, resulting from the breakdown of organic matter by a mix of microorganisms, is less concentrated in nutrients but improves soil structure and moisture retention. Worm castings are considered more potent, offering a quick nutrient boost, while compost is valued for its long-term soil health benefits.

Can I use worm castings on all types of plants?

Yes, worm castings can be used on all types of plants, including vegetables, flowers, houseplants, and lawns. Their gentle, natural composition makes them safe and beneficial, providing essential nutrients and improving soil health without the risk of harm.

How do I make worm tea with worm castings?

To make worm tea, steep worm castings in water for 24-48 hours. Use a ratio of about 1 cup of castings for every gallon of water. Stirring occasionally and aerating the mixture can enhance the process, encouraging the proliferation of beneficial microbes. After steeping, strain the liquid and use it to water plants or as a foliar spray.

How should I store unused worm castings?

Store unused worm castings in a cool, dry place. Ensure they are kept in a breathable container, such as a burlap sack or a bucket with holes, to maintain their quality and prevent mold growth. Keeping them aerated will preserve their beneficial microbial life.

Can worm castings attract pests to my garden?

No, worm castings themselves do not attract pests to your garden. Instead, they contribute to healthier soil and plant growth, which can actually help plants better resist pests and diseases. The beneficial microbes in worm castings can also play a role in suppressing soil-borne pathogens.

Can I use worm castings on all types of plants?

Yes, you can use worm castings on all types of plants. Their gentle, natural composition makes them safe and beneficial, providing essential nutrients and improving soil health without the risk of harm.

Is there such thing as too much worm castings?

While worm castings are safe and beneficial for plants, using them in excessive amounts is not recommended. Plants will not absorb nutrients beyond what they can absorb so adding too much will not harm your plants. Studies have shown that worm castings will only help to a certain amount so in the interest of saving time and money it’s probably best to stick within the recommended application guidelines.