Comparison: Best Organic Potting Soil With Worm Castings (Updated | Nov 11th)
We’ve all seen those lush, thriving gardens and wondered what the pros are using—well, this could be it. Packed with natural nutrients and beneficial microbes, these soils don’t just support growth—they supercharge it. In this comparison, we’ll break down the top contenders to help you choose the best blend for your indoor greens, outdoor veggies, or blooming beauties.
Editor’s Choice
Best for a specific purpose
- Best for give-back castings: Back to the Roots Organic Worm Castings for Plants
- Best for vegan moisture boost: Worm Bliss (1 Qt) – Organic Worm Castings for Plants & Gardening – OMRI-Listed Earthworm Castings for Plants
- Best for family farm bulk: Brut Organic Worm Castings for Plants 30 LB – Natural Nutrients
- Best for compact family pack: Brut Organic Worm Castings for Plants 5 LB – Natural Nutrients
- Best for expandable 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 all-purpose worm mix: Harris All Purpose Premium Potting Soil Mix with Worm Castings and Other Nutrients
- Best for vegan bulk bliss: Worm Bliss (8 Qts) – Organic Worm Castings for Plants & Gardening – OMRI-Listed Earthworm Castings for Plants
- Best for space-saving super soil: Compressed Organic Potting Soil for Garden
- Best for vegan gallon boost: Worm Bliss (1 Gallon) – Organic Worm Castings for Plants – OMRI-Listed Earthworm Castings Worm Fertilizer – Worm Castings Organic Fertilizer for Plants
- Best for microbe-rich potting: Brut Organic Potting Soil – 1CF
Product Comparison: Best Organic Potting Soil With Worm Castings
Give-Back Castings
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 Moisture Boost
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 Farm Bulk
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!
Compact Family Pack
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!
Expandable 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!
All-Purpose Worm Mix
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
Vegan Bulk Bliss
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.
Space-Saving Super Soil
Compressed Organic Potting Soil for Garden, Plants & Vegetables – Expands 4x When Mixed with Water – Indoor or Outdoor Use – Plant Food Mix Derived from Natural Coconut Coir & Worm Castings Fertilizer
Organic Plant Magic
- A LITTLE DOES A LOT – Easy to use compressed soil granules quickly expand up to 4X and make up to 3 gallons of soil. Light, compact, easy to carry, resealable bag saves space.
- NOURISH & SEE THEM FLOURISH – Packed with every essential nutrient plus 55+ trace minerals, this concentrated super soil feeds and grows strong beautiful vibrant plants better than ever!
- FAST ACTING & LONG LASTING – Easy to wet and stays moist 3X longer. Living soil gets water, air and nutrients to roots on demand. Perfect for all seeds, starts, transplants, containers, raised beds and gardens!
- TRULY ORGANIC YOU CAN TRUST – 100% natural ground coconut coir, worm castings, compost, humic acids, amino acids, kelp and beneficial GroBiotics including mycorrhizae give your soil, flower, vegetable, herb, fruit, tree, shrub, raised bed, outdoor or indoor potted house plants and more a super-boost.
- EASY to USE – Just add water 1:1 to compressed soil to expand up to 4X. Use 1 tsp for small seeds, 1 tbsp for large seeds, 1/4 cup per seedling, 1 cup per small plant, and 4 cups per gallon plant. Use expanded soil straight or blend 1:2 with other soil. Prevents overwatering, re-wets easily, and stays moist 3X longer. As mulch or top dress, apply 1/4 inch expanded soil or spread compressed soil and water. A 2 lb bag covers up to 20 sq ft.
Vegan Gallon Boost
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.
Microbe-Rich Potting
Brut Organic Potting Soil – 1CF, Premium Plant Soil with Organic Worm Castings, Trace Minerals & Perlite – Chemical-Free, Filler-Free – Ideal Potting Mix for Indoor & Outdoor Plants – 1pck
BRUT WORM FARMS
- NATURAL, ORGANIC INGREDIENTS: Made of 100% organic ingredients, this organic potting soil is free from synthetic fertilizers and chemicals. This planting soil gives your plants everything they need. Perfect for soil for indoor plants and outdoor potting soil.
- MICROBE-RICH SOIL: Packed with microbe-rich worm castings and trace minerals like Azomite and kelp, this organic soil feeds plants directly from the root level. Whether you’re growing vegetables, herbs, or flowers, Brut provides the nutrients they need.
- FOR ALL TYPES OF GARDENS: Brut Potting Soil is versatile, perfect as indoor plant soil. It works great for annuals, perennials, & herb plants. This all-purpose potting soil mix makes gardening easy for all plant types from indoor plants to outdoor gardens.
- PURE, FILLER-FREE: Say goodbye to the worry of unknown ingredients. It is pure and filler-free, with no sticks, wood chips, or artificial additives. Brut Organic Potting mix is naturally pH balanced between 6.3 and 6.5, making it perfect for most plants.
- CERTIFIED ORGANIC: Our Potting Soil is OMRI listed, representing true organic excellence and bringing the power of nature’s nutrients. Eco sustainable resorce for your gardening enjoyment!
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 key ingredients should I look for in an organic potting soil with worm castings?
The most important components are high‑quality worm castings, a balanced blend of organic nutrients, and supplemental amendments like mycorrhizae, kelp, or perlite for aeration. Look for products that list these ingredients prominently and avoid mixes with synthetic fertilizers or filler materials. Certifications such as OMRI or CDFA indicate that the soil meets organic standards.
How does the presence of coco coir affect soil performance compared to peat‑based mixes?
Coco coir provides excellent water retention while maintaining good drainage, which helps prevent root rot and reduces watering frequency. Unlike peat, coir is a renewable resource and typically has a neutral pH, making it suitable for a wider range of plants. Mixes like Wonder Soil and Harris combine coir with worm castings for a balanced, sustainable medium.
Which product offers the best value for large‑scale gardening projects?
For bulk applications, the 30 lb Brut Organic Worm Castings provide a high nutrient density at a lower per‑pound cost, making them ideal for raised beds or extensive container gardens. The 1 qt Worm Bliss and 1 gallon options are convenient for smaller spaces but cost more per unit of castings. Consider the size of your project and whether you need a pre‑mixed potting soil or pure castings to blend yourself.
Do any of these products include additional microbial inoculants, and why does that matter?
Yes, several mixes such as Wonder Soil, Worm Bliss, and Brut Potting Soil contain mycorrhizae, kelp, or other beneficial microbes that enhance nutrient uptake and improve soil structure. These microbes help break down organic matter, making nutrients more accessible to plant roots and increasing drought tolerance. Adding microbial‑rich soil can lead to healthier, more vigorous growth over time.
How important is the certification (OMRI, CDFA) when choosing organic potting soil?
Certification verifies that the product complies with strict organic standards, ensuring no synthetic chemicals or prohibited additives are present. For gardeners concerned about environmental impact or growing edible plants, certified products like Brut and Worm Bliss provide peace of mind. While non‑certified soils can still be effective, certifications help guarantee consistency and purity.
What are the benefits of using pure worm castings versus blends that dilute them with other ingredients?
Pure worm castings deliver a concentrated source of nitrogen, phosphorus, potassium, and trace minerals without the risk of nutrient burn. Blended mixes may include fillers or synthetic components that dilute the potency but can improve texture and water management. Choose pure castings like Back to the Roots if you want maximum nutrient density, or blended soils for easier handling and added moisture retention.
Can I mix a pure worm casting product with a coco‑coir based potting soil, and what ratio works best?
Yes, combining pure worm castings with coco coir creates a balanced medium that offers both nutrient richness and excellent water management. A common starting point is 10–20 % worm castings by volume mixed into the coir, adjusting based on plant type and growth stage. This blend provides strong root development while preventing over‑watering.
Which product is most suitable for indoor houseplants that need minimal odor and mess?
Back to the Roots Organic Worm Castings are marketed as odor‑free and low‑dust, making them ideal for indoor environments. Their small packaging also reduces the chance of spills, and the included satisfaction guarantee adds confidence for indoor gardeners. For a ready‑to‑use option, Wonder Soil’s compressed coco coir expands cleanly and includes castings without a strong smell.