Comparison: Best Organic Seed Starting Mix (Updated | Nov 11th)
Not all seed starting soils are created equal—especially when you’re going organic. We’ve tested and compared the top organic seed starting mixes so you don’t have to guess what works. From texture to germination success, we’ll break down what really matters.
- Best for expandable block: Back to the Roots Organic Seed Starting
- Best for 3-in-1 organic: Back to the Roots 3-in-1 Seed Starting Mix 6 Quarts
- Best for mycorrhizae boost: Espoma Organic Seed Starter Premium Potting Soil Mix – All Natural & Organic Seed Starting Mix with Mycorrhizae. For Organic Gardening
- Best for coconut coir brick: Burpee Organic Coconut Coir Concentrated Seed Starting Mix
- Best for large-volume starter: Espoma 16 qt. Organic Seed Starter Premium Potting Mix (2)
- Best for smart garden kit: Promix Premier Horticulture Organic Pro Seed Starting Mix; 16 qt with My Garden Pool PH Soil Test Strips 20 ct
- Best for 3-month feed: Premier Horticulture 1016041RGCE Organic Pro Seed Starting Mix
Product Comparison: Best Organic Seed Starting Mix
Back to the Roots Organic Seed Starting, Compressed Block expands to 12 Quarts, Made for Herbs, Veggies, Flowers
- A balanced pH, which means it’s truly all-purpose. Use alone or as an amendment for anything in a pot or in the ground — vegetables, flowers, herbs, and even starting seeds.
- Expands to 12 Quarts
- Peat Free OMRI Listed, assuring organic production, handling, and processing
- 100% SATISFACTION GUARANTEE: If you are not satisfied or have any issues with this product, just shoot us a note and our dedicated customer support team will make sure we get you growing or send you a refund/replacement.
- GROWONEGIVEONE — Share a photo of your growing garden and we’ll donate a Kids Grow Kit and STEM elementary school curriculum to a classroom of your choice.
Back to the Roots 3-in-1 Seed Starting Mix 6 Quarts, 100% Organic & USA Made for Herbs, Veggies, Flowers, w/Nutrient Rich Plant Food, Worm-Castings, & Moisture Controlling Yucca Brown
- NUTRIENT-RICH, NATURAL, AND ORGANIC SOIL: Grow a bountiful garden in your home with the Back to the Roots All-Purpose Natural and Organic Peat-Free 3-in-1 Seed Starting Mix, packed with the nutrients needed for your plants, flowers, and vegetables to thrive
- MYCORRHIZAE, YUCCA EXTRACT, AND COCONUT COIR FOR STRONG ROOT DEVELOPMENT: This organic potting soil has mycorrhizae, coconut coir, and yucca extract which enhances the root’s uptake of water and the nutrients required by your plants for growth
- FEATURES pH BALANCING DOLOMITIC LIMESTONE: The dolomitic limestone of this potting soil has a combination of calcium carbonate and magnesium carbonate which effectively neutralizes acidity and prevent nutrient deficiency
- ZERO-RISK GARDENING AND GREAT FOR THE PLANET: Made in the USA and 100% guaranteed to grow; If you have any problems, we will send you a new bag to get you growing; Mined peatlands contribute yearly CO2 emissions equivalent to what cars all over the world are releasing — that’s why we think it’s so important to leave peat alone and offer the 1st premium, 100% peat-free soil in the market
- THE PERFECT GIFT: The perfect holiday gift, it comes in a beautiful packaging so that it’s ready to be given to foodie, garden-loving and eco-conscious friends and family; This kit is also part of our Grow One Give One campaign, simply share a picture on social media, tag us and use the campaign hashtag, and we’ll donate a kit to a classroom of your choice
Espoma Organic Seed Starter Premium Potting Soil Mix – All Natural & Organic Seed Starting Mix with Mycorrhizae. For Organic Gardening, 16 qt, bag – Pack of One
- CONTAINS: This organic Seed Stating soil mix is a rich blend of sphagnum peat moss & perlite with yucca extract and lime to ensure correct pH.
- MYCO-TONE: A blend of endo & ecto mycorrhizae.
- WHEN TO USE: Use to germinate and start seeds. Great for flower, vegetable, herb & more plant types. Can also be used to root stem and leaf cuttings.
- PROMOTE ROOT GROWTH: Organic seed starter mix ensures ideal moisture retention and aeration.
- ORGANIC GARDENING: Contains a rich blend of only the finest natural ingredients. No synthetic plant foods or chemicals are used.
Burpee Organic Coconut Coir Concentrated Seed Starting Mix, 16 Quart
- ORGANIC COCONUT COIR: Made from recycled coconut husks, coir is a light, sustainable growing medium that holds the perfect amount of moisture for starting seeds. 100% biodegradable soil alternative. Environmentally-friendly and a renewable alternative to peat moss. OMRI listed and certified organic.
- IDEAL GROWING MIX: Improve seed germination and root growth with this premium coconut fiber mix, which improves nutrients absorption! Great for flower, vegetable, herb & more plant types. OMRI listed. Naturally disease and pathogen resistant, it will help you grow healthy live plants.
- EASY TO STORE & EXPAND: Each compact coconut coir brick expands into 8 quarts of seed starting mix, providing 16 quarts total. Just add water to expand! Dehydrated bricks save space until planting. Once expanded, coconut coir provides a quality growing medium for all types of plants – indoor plants, house plants, outdoor plants, and more!
- NATURALLY CONSERVES WATER: Renewable coco coir has excellent moisture retention and better air circulation than peat. This eco-friendly, premium seeds starting mix combines well with other potting soil and compost for container plants & raised beds.
- 100% GUARANTEED: Burpee is committed to the success of all gardeners. We treat each order with care to ensure healthy seeds, plants, soil mixes & gardening supplies are sent in excellent condition. If you are unsatisfied with your purchase, we aim to make it right!
Promix Premier Horticulture Organic Pro Seed Starting Mix; 16 qt with My Garden Pool PH Soil Test Strips 20 ct, and Gardening Claw Gloves and Garden-IQ, Smart Gardening AI Assistant!
- 🌿Organic and All-Natural Ingredients: Carefully selected to provide your seeds with a healthy, chemical-free start.
- 🌱Enriched with Mycorrhizae: For enhanced nutrient and water absorption, promoting stronger root development and plant growth.
- 🧪Easy pH Monitoring: Comes with 20 pH soil test strips for optimal soil condition management.
- 🌻Versatile Use: Ideal for a wide range of plants, ensuring your garden’s diverse needs are met.
- 🌱Promotes Healthy Seeds: Specially formulated to encourage vigorous seed germination and growth.
- 🌿Eco-Friendly Packaging: Committed to sustainability, our packaging is designed to minimize environmental impact.
- 🧠 Garden-IQ, Smart Gardening AI Assistant: Get smart advice and solutions tailored to your gardening needs.
- 🧤Superior Gardening Claw Gloves: In addition to the fertilizer and pH test strips, this package also includes My Garden Pool Superior Gardening Claw Gloves, offering maximum protection and comfort for your hands while working in the garden.
Premier Horticulture 1016041RGCE Organic Pro Seed Starting Mix, 16 Quart
- Size : 16 Quart
- Ingredients : Organic Fertilizer
- Organic premium seed starting mix is ideal for perennials and flowering shrubs
- Contains an organic fertilizer that gradually feeds for up to 3 months
- Contains MYCOACTIVE to stimulate vigorous growth and greater resistance
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 factors should I consider when choosing an organic seed starting mix?
Look for a balanced pH, moisture retention, and aeration to support germination. Ingredients like mycorrhizae, coconut coir, or peat-free blends can improve root development. Certifications such as OMRI listing ensure the product meets organic standards, and a clear guarantee can protect your investment.
How does the Back to the Roots compressed block compare to the Back to the Roots 3‑in‑1 6‑quart mix?
The compressed block expands to 12 quarts, making it space‑saving and ideal for small‑scale growers, while the 3‑in‑1 mix offers a ready‑to‑use 6‑quart bag with added dolomitic limestone for pH balancing. Both are peat‑free and contain mycorrhizae, but the 3‑in‑1 includes yucca extract and coconut coir for extra root strength. The block may be more convenient for storage, whereas the bag provides a ready‑mix with additional nutrients.
Which product gives the best value for larger garden projects?
Burpee’s Organic Coconut Coir Concentrated Mix expands to 16 quarts from a compact brick, offering a large volume at a reasonable price while being fully renewable and peat‑free. The Back to the Roots compressed block also yields 12 quarts, but the Burpee mix provides two extra quarts and a higher moisture‑retention capacity. For bulk planting, the larger expanded volume and lower cost per quart make Burpee a strong value choice.
Why might I prefer a peat‑free or coconut‑coir based mix over traditional peat?
Peat‑free mixes, such as those using coconut coir, reduce environmental impact because coir is a renewable by‑product of the coconut industry. Coconut coir also offers superior water retention and aeration, which helps prevent damping‑off diseases. Many growers choose peat‑free options to align with sustainable gardening practices and OMRI certification.
What benefits do mycorrhizae and other biological additives provide in these mixes?
Mycorrhizae form a symbiotic relationship with plant roots, enhancing nutrient and water uptake and improving stress tolerance. Products like Espoma Organic Seed Starter and Promix Premier include both endo‑ and ecto‑mycorrhizae for comprehensive support. Additional additives such as yucca extract and dolomitic limestone further promote root vigor and pH stability.
Do the listed mixes differ in how they manage soil pH?
Yes. The Back to the Roots 3‑in‑1 mix uses dolomitic limestone to neutralize acidity, while Espoma’s blend includes lime for pH balance. The coconut‑coir mixes are naturally near neutral but often incorporate pH‑adjusting agents; Burpee’s product relies on its coir’s inherent stability. Choosing a mix with explicit pH‑balancing ingredients can simplify seedling care.
Which mix is best suited for starting seeds versus transplanting seedlings?
For pure seed germination, lightweight, well‑aerated mixes like Espoma Organic Seed Starter or Promix Premier are ideal because they retain moisture without becoming compacted. For transplanting, a mix with added organic fertilizer, such as Premier Horticulture’s Organic Pro Seed Starting Mix, provides a longer nutrient release to support growing plants. Coconut‑coir based mixes work well for both stages thanks to their excellent moisture management.
How do sustainability and certification aspects compare among these products?
All listed mixes are OMRI‑listed, confirming they meet organic production standards. Burpee and Back to the Roots emphasize peat‑free formulations, reducing carbon footprints, while Espoma focuses on natural ingredients without synthetic chemicals. The Grow One Give One campaigns from Back to the Roots add a social‑impact dimension, making those options appealing for eco‑conscious shoppers.