Super-Powered Soils

New potting mixes ensure healthier, more resilient plants

Potting bench with soil, pots and seedlings

Like a healthy aboveground ecosystem, healthy soil contains a vibrant community of living organisms, many of which are microscopic but play an outsized role in supporting the plant life above. These microbes include an astonishing array of fungi, bacteria and protozoa — scientists estimate that there are more of them in a teaspoon of healthy soil than there are people on the earth!

Mycorrhizae (my-co-RISE-ee), also called root fungi, form one important group of beneficial microbes. These specialized fungi attach to a plant's roots, and then form a web of filaments called hyphae that reach far into the soil. These filaments act as extensions of the plant's roots, exponentially increasing the surface area of the roots and boosting the plant's ability to take up water and nutrients. They also release powerful enzymes that help extract nutrients that would otherwise be unavailable to plants.

Mycorrhizae improve a plant's resilience to stress, including drought and temperature extremes, and they help minimize transplant shock. In return, the plant provides the mycorrhizae with the sugars they need for energy, resulting in a mutually beneficial relationship between plant and fungi.

We've harnessed the power of mycorrhizae in our new and improved potting mixes. For gardeners, this translates to healthier plants with up 35% higher yields compared to soil mixes without mycorrhizae.

  • SuperRoot Booster contains a naturally occurring mycorrhizae called Glomus intraradices, a superstar among mycorrhizae for the benefits it confers to host plants. You'll find SuperRoot Booster in our Seed Starting Mix, Potting Mix, Self-Watering Potting Mix, Organic Self-Watering Potting Mix and Transplant Mix.
  • Bio-Blended Compost is a carefully balanced mix of expertly composted natural materials that teems with beneficial soil life — including abundant mycorrhizae — that ensures healthy, vigorous, resilient plants. You'll find Bio-Blended Compost in our Organic Seed Starting Mix and Organic Potting Mix.

Garden-Tested and Guaranteed

Our exclusive soil blends are ready to grow your healthiest, most robust plants. How do we know? We tested them, in our trial gardens and at 14 test sites across the country. Results show that our new soils promote healthier foliage, more blooms and a bigger, better harvest.

Pepper seedlings

Pepper seedlings grown in competitor's potting mix, left, vs. our Organic Seed Starting Mix with Bio-Blended Compost, right.

Basil seedlings

Basil seedlings growing in competitor's potting mix, left, vs. our new Potting Mix with SuperRoot Booster, right.

Cucumber seedlings

Cucumber seedlings growing in competitor's potting mix, left, vs. our new Potting Mix with SuperRoot Booster, right.

Tomatoes growing at a test site

Tomato plants growing in a variety of potting mixes at one of our test sites.

Evaluating growth rates of tomatoes

Evaluating plant growth in different potting mixes.

Test of potting soils

Plant on left was grown in our Organic Potting Mix with Bio-Blended Compost; plant on right was grown in a competitor's potting soil.

Last updated: 07/17/2023