How to Sustainably Seed Start with the Soil Block Method

In the quest for more sustainable gardening practices, many gardeners are turning to innovative methods that reduce waste and promote healthier plant growth. One effective technique is the soil block method, which eliminates the need for plastic in seed starting, making it an ideal choice for eco-conscious gardeners.

What is a soil blocker?

A soil blocker is a specialized gardening tool designed to create compact cubes of soil, known as soil blocks, which serve as seed starting containers. Instead of relying on traditional plastic seed trays, a soil blocker compresses a specially formulated soil mix into blocks that maintain their shape and integrity. Each block features a small indentation on top, perfect for planting seeds.

Why use a soil blocker?

Here are some compelling reasons to adopt the soil block method in your gardening practices:

• Eco friendly: The soil block method significantly reduces plastic waste by eliminating the need for disposable seed pots. This shift not only benefits the environment but also promotes a more sustainable approach to gardening.

• Healthier plants: Soil blocks encourage a natural process known as “air pruning.” As seedlings grow, their roots reach the edges of the block and are pruned by exposure to air. This results in stronger, healthier root systems and minimizes transplant shock when it’s time to move the plants into the garden.

• Space saving: The compact nature of soil blocks allows gardeners to maximize their growing space. You can fit numerous soil blocks into a small area, making it an efficient method for starting seeds.

How does it work?

Using a soil blocker is a straightforward process:

1. Prepare your soil mix: Start with a damp, nutrient-rich soil mix designed for seed starting. (Our recipe is below)
2. Fill the soil blocker: Load the soil blocker with the prepared mix, ensuring it is well-compacted.
3. Create the blocks: Press the filled soil blocker into a tray or directly onto a surface, then release the blocks.
4. Plant the seeds: Place seeds in the small indentations on top of each soil block.
5. Transplanting: As the seedlings grow, their roots will remain contained within the block until they are ready to be transplanted into the garden.

Our soil block mix

For optimal results, we recommend using the following soil mix. There are many recipes online. Many of the recipes include greensand, however we do not have that on hand. Use what you have available.

• 2 small buckets of coco coir
• 2 small buckets of sifted compost
• 1 small bucket of worm castings
• 1 small bucket of perlite
• 1 tablespoon of glacial rock dust for added minerals (optional)

This mix provides the essential nutrients and drainage needed for healthy seedling growth.

Soil blocker sizes

There are three main sizes of soil blockers to accommodate different planting needs:

• Micro 20: Produces 2 cm cubes, ideal for tiny seeds or herbs.
• Mini 4: Creates 5 cm cubes with insert pins (dowel, cube, and seed pins sold separately), suitable for a variety of seedlings.
• Maxi 1: Forms 10 cm soil blocks with a 5 cm indentation, perfect for larger plants.

These tools are available from @westcoastseeds, here is our link.

By embracing the soil block method, you not only contribute to a more sustainable gardening practice but also promote healthier plants that thrive in their natural environment. With the elimination of plastic and the enhancement of root development, soil blocks offer a practical and eco-friendly solution for seed starting. 

Consider making the switch today!

You can watch our video too!