Comparison: Best Worm Castings Potting Soil (Updated | Nov 11th)
But with so many options out there, how do you know which one delivers real results? We’ve dug into the dirt—literally—to compare the **best worm castings potting soil**s on the market. From nutrient richness to texture and value, we’re breaking it down so you can choose with confidence and watch your garden thrive like never before.
Editor’s Choice
Best for a specific purpose
- Best for coco-coir blend: Harris All Purpose Premium Potting Soil Mix with Worm Castings and Other Nutrients
- Best for pure vermicompost: Back to the Roots Organic Worm Castings for Plants
- Best for vegan worm castings: Worm Bliss (1 Qt) – Organic Worm Castings for Plants & Gardening – OMRI-Listed Earthworm Castings for Plants
- Best for family organic: Brut Organic Worm Castings for Plants 5 LB – Natural Nutrients
- Best for bulk organic power: Brut Organic Worm Castings for Plants 30 LB – Natural Nutrients
- Best for large vegan blend: Worm Bliss (8 Qts) – Organic Worm Castings for Plants & Gardening – OMRI-Listed Earthworm Castings for Plants
- Best for compressed coco mix: WONDER SOIL Organic Potting Soil | Ready to Plant Coco Coir Fully Loaded with Nutrients | 3 LBS Bag Expands to 12 Quarts of Indoor Outdoor Soil for Gardens & Plants | Incl Worm Castings
- Best for gallon purity: Worm Bliss (1 Gallon) – Organic Worm Castings for Plants – OMRI-Listed Earthworm Castings Worm Fertilizer – Worm Castings Organic Fertilizer for Plants
- Best for pure fertilizer: Wiggle Worm 100% Pure Organic Worm Castings Fertilizer
- Best for two-gallon boost: Worm Bliss (2 Gallons) – Organic Worm Castings for Plants & Gardening – OMRI-Listed Earthworm Castings for Plants
Product Comparison: Best Worm Castings Potting Soil
Coco-Coir Blend
Harris All Purpose Premium Potting Soil Mix with Worm Castings and Other Nutrients, 4 Quarts
HARRIS
- All Purpose Potting Mix – Use indoors and outdoors for container gardening, flower boxes, hanging baskets and more
- Contains Worm Castings – A plant superfood, worm castings provide essential nutrients to plants including iron, sulfur, calcium, nitrogen, phosphorus and potassium
- Fast Drainage – Contains pumice and perlite to promote aeration of roots and fast drainage
- Formulated with Coco Coir – A sustainable resource that helps maintain moisture for vibrant flowers, vegetables and herbs
Pure Vermicompost
Back to the Roots Organic Worm Castings for Plants, Natural Fertilizer and Soil Enhancer for Gardening, Made in The USA, 5lb
Back to the Roots
- Earth Worm castings from Mother Earth provide the best soil amendment for anything indoors or outdoors, including vegetables, herbs, flowers and houseplants. Pure USA Vermicompost, so there’s no burn or odor.
- Contains beneficial microbes to enhance your soil and protect seedlings from harmful pathogens.
- Develop your garden more sustainably as worm castings reduce the need for fertilizers.
- 100% SATISFACTION GUARANTEE: If you are not satisfied or have any issues with this Organic Worm Castings, just shoot us a note and our dedicacted customer support team will make sure we get you growing or send you a refund/replacement.
- #GROWONEGIVEONE — share a photo of garden with #GrowOneGiveOne and we’ll donate an Organic Gardening Kit + STEM curriculum to an elementary school classroom of your choice!
Vegan Worm Castings
Worm Bliss (1 Qt) – Organic Worm Castings for Plants & Gardening – OMRI-Listed Earthworm Castings for Plants, Vegetables, Flowers, & Potting Soil – Organic Garden Fertilizer Rich in Nutrients
plantonix
- Organic Worm Castings for Garden Soil – Plantonix Worm Bliss is a 100% organic fertilizer and soil amendment that mixes with potting soil for indoor plants and outdoor plants. Worm castings are rich in essential nutrients like nitrogen, phosphorus, and potassium, as well as trace minerals that improve soil conditions for better overall plant mass.
- 100% Vegan & Manure-Free – We raise our worms in a climate controlled facility and feed them a strictly vegan diet. Our earth worm castings for plants are meticulously screened to get rid of any traces of dirt, sand, or rocks, leaving you with nothing but pure worm castings for plants, unlike others who dilute their castings with synthetic ingredients or additives.
- Supports Beneficial Microbial Activity – Using earthworm castings for plants encourages soil microbes that break down organic matter and convert nutrients into forms that plants can easily absorb. These microbes are crucial for increasing nutrient availability and building drought tolerance for a more balanced soil ecosystem.
- Excellent Water Retention – The humus in worm castings improves the soil’s ability to retain moisture, so you can rest assured knowing your plants are staying happy and hydrated. Worm humus for plants reduces the need for frequent watering, so you can save water and promote more sustainable gardening practices.
- Improves Soil Structure & Aeration – Using organic worm castings for plants increases the porosity of the soil, creating a well-oxygenated environment that supports efficient water and nutrient uptake. This makes earth worm castings organic fertilizer an excellent choice for plants, potting soil, potting mixes, garden containers, garden terraces, flowers, garden soil for vegetables, and more.
Family Organic
Brut Organic Worm Castings for Plants 5 LB – Natural Nutrients, Fertility Builder, Plant Food for Potting Soil and Garden Soil – Indoor and Outdoor Use
BRUT WORM FARMS
- SUPERCHARGE YOUR GARDEN: Elevate your plants’ growth with premium organic Brut Worm Castings. Our certified organic formula guarantees optimal nutrition for your indoor and outdoor plants.
- PURE ORGANIC GOODNESS: Made with certified organic ingredients, our worm castings are raised indoors in containers, ensuring unparalleled purity and effectiveness for your plants’ health.
- LUSH & VIBRANT PLANTS: Watch your plants thrive with mineral-rich Brut Worm Castings. Experience lush greenery, vibrant blooms, and bountiful harvests—naturally nourishing your plants from root to leaf.
- BORN FROM FAMILY CARE: As a family-owned business, we take pride in offering the finest organic castings. Every batch is carefully crafted to nurture your plants as if they were our own.
- CERTIFIED ORGANIC: Our castings are OMRI and CDFA listed, representing true organic excellence and bringing the power of nature’s nutrients directly to your plants’ roots. Eco sustainable resorce for your gardening enjoyment!
Bulk Organic Power
Brut Organic Worm Castings for Plants 30 LB – Natural Nutrients, Fertility Builder, Plant Food for Potting Soil and Garden Soil – Indoor and Outdoor Use
BRUT WORM FARMS
- SUPERCHARGE YOUR GARDEN: Elevate your plants’ growth with premium organic Brut Worm Castings. Our certified organic formula guarantees optimal nutrition for your indoor and outdoor plants.
- PURE ORGANIC GOODNESS: Made with certified organic ingredients, our worm castings are raised indoors in containers, ensuring unparalleled purity and effectiveness for your plants’ health.
- LUSH & VIBRANT PLANTS: Watch your plants thrive with mineral-rich Brut Worm Castings. Experience lush greenery, vibrant blooms, and bountiful harvests—naturally nourishing your plants from root to leaf.
- BORN FROM FAMILY CARE: As a family-owned business, we take pride in offering the finest organic castings. Every batch is carefully crafted to nurture your plants as if they were our own.
- CERTIFIED ORGANIC: Our castings are OMRI and CDFA listed, representing true organic excellence and bringing the power of nature’s nutrients directly to your plants’ roots. Eco sustainable resorce for your gardening enjoyment!
Large Vegan Blend
Worm Bliss (8 Qts) – Organic Worm Castings for Plants & Gardening – OMRI-Listed Earthworm Castings for Plants, Vegetables, Flowers, & Potting Soil – Organic Garden Fertilizer Rich in Nutrients
plantonix
- Organic Worm Fertilizer for Plants – Worm castings are a 100% natural soil amendment and garden fertilizer for indoor plants and outdoor plants. Organic earthworm castings are rich in essential nutrients like nitrogen, phosphorus, and potassium, as well as trace minerals that improve soil conditions for better overall plant mass.
- 100% Vegan & Manure-Free – We raise our worms in a climate controlled facility and feed them a strictly vegan diet. The castings are meticulously screened to get rid of any traces of dirt, sand, or rocks, leaving you with nothing but pure worm castings for plants, unlike others who dilute their castings with synthetic ingredients or additives.
- Supports Microbial Activity – Using earthworm castings for plants encourages soil microbes that break down organic matter and convert nutrients into forms that plants can easily absorb. These microbes are crucial for increasing nutrient availability and building drought tolerance for a more balanced soil ecosystem.
- Excellent Water Retention – The humus in worm castings improves the soil’s ability to retain moisture, so you can rest assured knowing your plants are staying happy and hydrated. This reduces the need for frequent watering, so you can save water and promote more sustainable gardening practices.
- Improves Soil Structure & Aeration – Using organic worm castings for plants increases the porosity of the soil, creating a well-oxygenated environment that supports efficient water and nutrient uptake. This makes Worm Bliss an excellent plant fertilizer for potting soil, potting mixes, garden containers, garden terraces, vegetables, flowers, and more.
Compressed Coco Mix
WONDER SOIL Organic Potting Soil | Ready to Plant Coco Coir Fully Loaded with Nutrients | 3 LBS Bag Expands to 12 Quarts of Indoor Outdoor Soil for Gardens & Plants | Incl Worm Castings, Perlite
Wonder Soil
- NUTRIENT RICH & INDOOR/OUTDOOR FAST GERMINATION… Wonder Soil Premium Organic Potting Soil Mix is the only dry compressed coco coir mix with added amendments of worm castings, mycorrhizae, kelp, perlite and more! Grow your plants faster with stronger roots! Peat free, all natural, family and pet safe!
- A LITTLE DOES A LOT… your little BIG bag of compressed indoor potting soil & garden soil for outdoor plants expands to 4 TIMES THE SIZE when mixed with water; easy to carry & saves vital shed space.
- PRE-MIXED & READY TO USE ORGANIC POTTING MIX … Pre-mixed and ready to use organic potting soil and garden soil mix to help make your gardening or hobby growing a breeze. Simply transplant your desired plants into their new container and add our soil mix or pour our soil mix and plant your seeds.
- WATER RETENTION & DRAINAGE… Coco coir has excellent water retention with dependable drainage and aeration in the root zone. Save up to 50% of water, fertilizer, and seed!
- HEAVY DUTY RESEALABLE BAG… Use what you need and save the rest for later! Keeping your planting soil dry and safe!
Gallon Purity
Worm Bliss (1 Gallon) – Organic Worm Castings for Plants – OMRI-Listed Earthworm Castings Worm Fertilizer – Worm Castings Organic Fertilizer for Plants, Potting Soil, Garden Soil, & Seed Starter Soil
plantonix
- Organic Worm Castings for Garden Soil – Plantonix Worm Bliss is a 100% organic fertilizer and soil amendment that mixes with potting soil for indoor plants and outdoor plants. Worm castings are rich in essential nutrients like nitrogen, phosphorus, and potassium, as well as trace minerals that improve soil conditions for better overall plant mass.
- 100% Vegan & Manure-Free – We raise our worms in a climate controlled facility and feed them a strictly vegan diet. Our earth worm castings for plants are meticulously screened to get rid of any traces of dirt, sand, or rocks, leaving you with nothing but pure worm castings for plants, unlike others who dilute their castings with synthetic ingredients or additives.
- Supports Beneficial Microbial Activity – Using earthworm castings for plants encourages soil microbes that break down organic matter and convert nutrients into forms that plants can easily absorb. These microbes are crucial for increasing nutrient availability and building drought tolerance for a more balanced soil ecosystem.
- Excellent Water Retention – The humus in worm castings improves the soil’s ability to retain moisture, so you can rest assured knowing your plants are staying happy and hydrated. Worm humus for plants reduces the need for frequent watering, so you can save water and promote more sustainable gardening practices.
- Improves Soil Structure & Aeration – Using organic worm castings for plants increases the porosity of the soil, creating a well-oxygenated environment that supports efficient water and nutrient uptake. This makes earth worm castings organic fertilizer an excellent choice for plants, potting soil, potting mixes, garden containers, garden terraces, flowers, garden soil for vegetables, and more.
Pure Fertilizer
Wiggle Worm 100% Pure Organic Worm Castings Fertilizer, 30-Pounds – Improves Soil Fertility and Aeration for Houseplants, Vegetables, Gardens, and More – OMRI-Listed and Mineral-Dense
Wiggle Worm
- Pure Earthworm Castings – WIGGLE WORM Worm Castings is pure castings, not vermicompost, and is one of the only castings products to be recognized as a fertilizer. This is because of our special manufacturing and harvesting process. It’s not uneaten worm bedding with some worm castings, so it’s pure, nutrient-rich, and mineral-dense
- Improves Soil Structure – WIGGLE WORM Pure Worm Castings contain tiny, football-shaped particles to help improve plant soil aeration. Our soil supplement also helps improve the root’s water retention capacity
- Indoor and Outdoor Use – WIGGLE WORM Pure Worm Castings are great for both outdoor and indoor gardens because it’s odorless and non-toxic. Our worm castings are an excellent organic fertilizer for vegetables, flowers, houseplants, and more
- Easy-to-Use – A little goes a long way with WIGGLE WORM, so a handful or half a cup is all you need. Apply our worm castings for gardening into the soil above the root zone three times a year or to the hole during transplant or seeding
- OMRI listed for organic use – The simple fact is that Earthworm Castings were created by nature for the purpose of promoting optimum plant growth and everything required to provide it, is found in them
Two-Gallon Boost
Worm Bliss (2 Gallons) – Organic Worm Castings for Plants & Gardening – OMRI-Listed Earthworm Castings for Plants, Vegetables, Flowers, & Potting Soil – Organic Garden Fertilizer Rich in Nutrients
plantonix
- Organic Worm Castings for Garden Soil – Plantonix Worm Bliss is a 100% organic fertilizer and soil amendment that mixes with potting soil for indoor plants and outdoor plants. Worm castings are rich in essential nutrients like nitrogen, phosphorus, and potassium, as well as trace minerals that improve soil conditions for better overall plant mass.
- 100% Vegan & Manure-Free – We raise our worms in a climate controlled facility and feed them a strictly vegan diet. Our earth worm castings for plants are meticulously screened to get rid of any traces of dirt, sand, or rocks, leaving you with nothing but pure worm castings for plants, unlike others who dilute their castings with synthetic ingredients or additives.
- Supports Beneficial Microbial Activity – Using earthworm castings for plants encourages soil microbes that break down organic matter and convert nutrients into forms that plants can easily absorb. These microbes are crucial for increasing nutrient availability and building drought tolerance for a more balanced soil ecosystem.
- Excellent Water Retention – The humus in worm castings improves the soil’s ability to retain moisture, so you can rest assured knowing your plants are staying happy and hydrated. Worm humus for plants reduces the need for frequent watering, so you can save water and promote more sustainable gardening practices.
- Improves Soil Structure & Aeration – Using organic worm castings for plants increases the porosity of the soil, creating a well-oxygenated environment that supports efficient water and nutrient uptake. This makes earth worm castings organic fertilizer an excellent choice for plants, potting soil, potting mixes, garden containers, garden terraces, flowers, garden soil for vegetables, and more.
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.com at the time of purchase will apply to the purchase of this product.
Buying Guide
FAQs
What should I look for when choosing a worm castings potting mix?
Check for pure, organic castings without synthetic additives, and verify OMRI or other organic certifications. Look for added components like perlite, pumice, or coco coir that improve drainage and moisture retention. Also consider the product’s nutrient profile, especially nitrogen, phosphorus, and potassium levels.
How does a pre‑mixed potting soil with worm castings compare to pure castings you add yourself?
Pre‑mixed blends, such as Harris All Purpose or Wonder Soil, provide a ready‑to‑use balance of aeration, drainage, and nutrients, saving time and effort. Pure castings like Back to the Roots let you control the exact amount added, which can be more economical for large gardens. The choice depends on whether you value convenience or customization.
Are vegan, manure‑free worm castings worth the extra cost?
Vegan, manure‑free options like Worm Bliss guarantee that the castings contain no animal waste, reducing the risk of pathogens and odor. They often undergo extra screening for purity, which can justify a higher price for sensitive indoor plants. If you grow edibles or have pets, the added safety may be worthwhile.
Which product offers the best value for large‑scale gardening?
For bulk applications, Brut Organic Worm Castings in 30 lb bags provide a high nutrient density at a lower per‑pound price. Worm Bliss also offers larger gallon containers that balance price with convenience. Compare the cost per pound of castings and any included amendments to determine the most economical choice.
Do added microbes in products like Back to the Roots make a difference?
Beneficial microbes help break down organic matter and protect seedlings from harmful pathogens, promoting healthier root development. While most pure castings contain natural microbes, products that highlight microbial content may offer a more consistent boost. This can be especially helpful for new gardeners or those growing sensitive varieties.
How important is water retention in a worm‑casting soil mix?
Worm castings increase the soil’s ability to hold moisture, reducing the frequency of watering and preventing drought stress. Blends that include coco coir, perlite, or pumice, like Harris All Purpose, enhance both retention and drainage, creating a balanced environment. Choosing a mix with good water‑holding capacity can save time and water usage.
Is there a noticeable performance difference between organic‑certified and non‑certified castings?
Organic‑certified castings meet strict standards for purity and environmental impact, which can translate to more reliable nutrient content. Non‑certified products may still be effective but could contain fillers or lower concentrations of beneficial minerals. For gardeners prioritizing sustainability and consistent results, certified options are generally preferable.
Can I use worm castings as a sole growing medium for indoor plants?
While worm castings are nutrient‑rich, they lack the structure needed for optimal aeration and drainage on their own. Mixing castings with a base like coco coir, perlite, or a commercial potting mix creates a well‑balanced medium. Using a blend ensures roots receive both nutrients and proper airflow.