You can make your own mix:
- 30% peat moss or coco coir
- 30% perlite or vermiculite
- 30% compost or soil
Among the mixes in the store, Miracle-Gro 32-Quart Potting Soil/Mix seems to be the best choice. Don't use garden soil because it is too heavy, it will absorb too much water and will drown the plants.
The cost of Miracle-Gro 32-Quart Potting Soil is less than $10 at Lowe's, Home Depot or Walmart, and should be enough for 6-8 eight-inch planters.
Some users report gnat infestation with Miracle-Gro 32-Quart Potting Soil (check the Amazon reviews).
FoxFarm FX14053 12-Quart Ocean Forest Organic Potting Soil gets great reviews but it is considerable more expensive than Miracle-Gro Potting Soil.
Here are the Approved Growing Media for EarthBox (Potting Mix and Potting Soil are the same).
Depending on where you reside in the U.S., growing media that is suitable for container gardening may be called Potting Mix or Potting Soil.
EarthBox manufacturer recommends using 2 cubic feet (60 dry quarts) of a peat-based (70%-80%) growing media that contains perlite or vermiculite. It should be light and fluffy when dry, and spongy when wet. It should NOT contain any rock, clay, or sand. You should also avoid using topsoil or compost.
The following brands are suitable for planting in the EarthBox:
EarthBox Potting Mix
EarthBox Organic Potting Mix
Lambert Potting Mix
Lambert 100% Organic Potting Mix
Jeff’s Natural Solutions All Organic Growing mix
Premier Horticulture Pro-Mix BX
Premier Horticulture Pro-Mix for Potting & Seeding
Premier Horticulture Pro-Mix Ultimate Organic Mix
Premier Horticulture Bio-Max Garden Mix 3-in-1
Premier Horticulture LiteWay Potting Soil
Espoma Organic Potting Mix
Fox Farm Happy Frog Potting Soil
Jungle Growth Flower & Vegetable Professional Mix
Jungle Growth Pure Organic Potting Mix
Scott’s Miracle-Gro Potting Mix
Scott’s Miracle-Gro Organic Choice Potting Mix
Fafard All Purpose Potting Mix
Fafard Container Mix
E.B. Stone Organics Edna’s Best Potting Soil
E.B. Stone Organics Flower & Vegetable Planting Mix
Kellogg Champion’s Blend Premium Potting Soil
Kellogg Premium Potting Soil
EKO Compost Premium All-Purpose Potting Mix
EKO Compost Premium Outdoor Planting Mix
ASB Greenworld Original Grower Mix
ASB Greenworld Original Grower Mix with Perlite
ASB Greenworld Professional Seed & Plug Mix
Baccto Professional Planting Mix
Baccto Lite Premium Potting Soil
Gardner & Bloom Blue Ribbon Blend Premium Potting Soil
Ferti-lome Ultimate Potting Mix
Sun Gro Horticulture Metro Mix Potting Medium (350, 360...)
Black Gold Seedling Mix
Black Gold Natural & Organic Potting Soil
Sunshine Container Potting Mix
Sunshine Seed Starter Mix
Nature’s All Organic Potting Soil
SummerWinds Potting Soil
Any private label growing media that meets the above specifications
Raised Garden Bed: What soil to select? http://goo.gl/0sbtK (Note: Garden soil is different from potting soil).
Using Soil and Soil Mixes - Successful Container Gardens - University of Illinois Extension http://goo.gl/IJm73
EarthBox: Approved Growing Media http://goo.gl/i77fq
How to Create a Potting Mix for Self-Watering Containers | eHow.com http://goo.gl/nmN3K
How Many Pots Can You Fill with a Bag of Soil? - Bonnie Plants http://goo.gl/KYE5T
Growing Vegetables according to the season | eHow.com http://goo.gl/izBCe
Best Source of Garden Soil to Grow Your Vegetables. - YouTube http://goo.gl/FxsPm
Vermiculite shopping options:
2.0 cu. ft. Vermiculite (Medium Grade), $25, free shipping at The Home Depot http://bit.ly/PN6knJ
Shop Sta-Green 1.5 cu ft Vermiculite at Lowes.com (available locally) http://low.es/PN6n2U
Horticultural Vermiculite at Brew & Grow, $25, 4 cu/ft http://bit.ly/PN6vPX