Soil Blocked Plant Starts

Reducing Waste Through Input Reduction

Input reduction is one of our four key values here on the farm, and one of the ways that we strive to follow that is by decreasing our reliance on plastics and other waste products. Instead, we utilize a method of plant propagation known as soil blocking, which essentially uses slightly compressed blocks of soil to grow seedlings in place of traditional plastic pots. The reasons for doing this are many, most notably that soil blocking creates a healthier plant (via “air pruning” of the roots) that is less prone to transplant shock, and it also helps to eliminate the sometimes single-use nature of plastic plant pots. It’s a win for the garden and the environment!

Soil Blocking innovation

A Bigger, Better Soil Blocker

In 2025, we received a grant from the Tilth Alliance to finance the construction of a commercial capacity soil block press, capable of creating half gallon and larger soil blocks on an industrial scale.

Currently, the largest soil blocker available on the market only goes up to 4-inches in diameter, meaning that any commercial nursery wanting to sell plants year-round is forced to use large, wasteful, and expensive plastic pots.

At Blue Ridge Farm, a huge part of our regenerative farming model involves decreasing our reliance on outside inputs like those very plastic plant pots. This meant figuring out how to design a press that could create larger soil blocks for growing out tree seedlings and other perennials. As the general design elements of a soil block press have proven effective and efficient in smaller models, there was no reason why it wouldn’t work on a larger-sized scale.

The first prototype we built (shown in the picture) was a stainless-steel bottom-loading press in the same manner as the smaller ones currently on the market. While this press works, it is difficult to load given its larger and heavier size.

However, building and using this initial prototype did teach us many valuable lessons, as well as what we should have done differently. After much contemplation (and listening to his spouse gripe), Ryan Garrett came up with a design for a top-loading soil block press on a pivot arm, which would be able to quickly and easily press out large soil blocks in a multitude of shapes and sizes.

When complete, this soil press will be utilized to expand our farm’s already popular offerings of soil blocked plants, now to include more mature trees, shrubs, and perennials - all while simultaneously eliminating the need for larger plastic pots. The bigger soil blocks will also help protect delicate taproots during transplanting, drastically decreasing any risk of transplant shock death.

This large capacity soil block press will help uphold our farm’s continued commitment to input and waste reduction, while also making it one of – if not the only – farm in the nation to offer this unique product.

Understanding Air Pruning Vs. Rootbound

Soil Blocking Promotes Healthier Plants

Have you ever wondered why that big potted plant that you bought at the store never thrived in your garden? Were you curious as to why, when you finally dug up that dead plant, its roots were still in the original shape of the plastic pot?

The answer to these questions is that the poor plant was suffering from a condition known as “rootbound,” brought about by too much time spent having its roots constricted in a plant pot. Rootbound plants are a common occurrence, and one of the many reasons that we constantly remind customers that the size of a transplant doesn’t matter – it’s how healthy the roots are!

One of the many reasons that we turned to soil blocking as our method of plant propagation was because it is such a fantastic way of ensuring healthy plants. Soil blocking utilizes a process known as “air pruning,” which promotes a healthier root system than putting plants in a pot. In a soil block, air pruning occurs when the plant roots hit the outside air of the soil block edges and are effectively “burned” off, causing the plant to consistently produce new branching roots (thereby creating a very healthy root system).

In a traditional plastic pot, the plant roots are constricted and have nowhere to go, heading down to the bottom of the pot and swirling around indefinitely. This creates an unhealthy condition known as being “rootbound,” which can not only stunt a plant but also potentially kill it. After being put in the ground, a rootbound plant can continue to be stunted, unable to overcome its constricted root system, or take much longer to establish than a healthier air pruned plant. This is one of the many reasons we prefer to utilize soil blocking. The plants we offer for sale as well as the ones we grow on the farm are happier, healthier, and far more productive as a result!