How to Create Soil Blocks for Healthy Plant Starts

Properly created soil blocks will result in vigorous and healthy plant starts that grow into thriving transplants for your garden.

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what is soil blocking?

Soil blocks, as the name suggests, are compact cubes of soil used for starting seeds. Unlike seed-starting methods that rely on plastic trays or pots, soil blocks eliminate the need for containers. Instead, the seedlings grow directly in the soil medium, providing several advantages that contribute to healthier plants and a more sustainable gardening approach.

What are the benefits of soil blocking?

Using soil blocks for starting seeds offers several benefits for both the gardener and the environment:

1. Reduction of Plastic Waste: Soil blocks eliminate the need for plastic seed starting trays or pots commonly used in other seed-starting methods. By reducing the number of disposable containers, gardeners can significantly reduce the amount of plastic waste generated during the gardening process, contributing to a more sustainable lifestyle.
2. Improved Root Development: Soil blocks promote air pruning of roots, preventing them from becoming root-bound as they might in seed starting trays or pots. This encourages the development of a robust root system, which is essential for the long-term health and vitality of plants. Healthy roots lead to healthier, more vigorous seedlings. Thus seedlings are better equipped to thrive when transplanted into the garden.
3. Enhanced Moisture Retention: The compact nature of soil blocks helps retain moisture more effectively compared to traditional containers. This means less frequent watering is required, conserving water resources and reducing the risk of overwatering, which can lead to root rot and other issues down the line. Consistent moisture levels promote optimal seed germination and seedling growth.
4. Cost-Effectiveness: While there may be an initial investment in soil block-making tools, the long-term cost savings can be significant. By eliminating the need for disposable seed starting trays or pots, gardeners can save money on supplies over time, making soil blocks a cost-effective solution for seed starting.
5. Versatility: Soil blocks can accommodate a wide variety of plant species, from vegetables and herbs to flowers. Their versatility makes them suitable for virtually any type of garden, whether it’s a small urban plot, a raised bed, or a larger-scale farm. Gardeners have the flexibility to start seeds for various crops using soil blocks, simplifying their gardening process.
6. Reduced Transplant Shock: When it comes time to transplant seedlings into the garden or larger containers, soil blocks offer an advantage. The absence of containers means there’s no need to disturb the roots when transplanting, reducing the risk of transplant shock. Seedlings can be transferred directly into the soil without any disruption to their root systems, leading to smoother transitions and healthier plants.

What do you need to create soil blocks?

• Soil block maker (available in various sizes) or Swift Blocker
• High-quality seed starting mix
• Water
• 1020 trays (I prefer ones with holes so water doesn’t sit in the tray) or other flat tray surface

step-by-step how to create soil blocks

1. Prepare the Soil Mix
   • In a large container, mix the seed starting mix with water until it reaches a moist, but not soggy, consistency. The soil should hold together when squeezed, but not be dripping with water.
2. Fill the Soil Block Maker
   • Take your soil block maker and fill it with the moist soil mix. Press the soil down firmly into each compartment, ensuring there are no air pockets.
   • Scrap excess soil off of the bottom of the blocks (you want the bottom to be flat)
3. Create Soil Blocks
   • Place the soil block onto a flat surface, such as a tray or a flat.
   • Gently squeeze the handle on the soil blocker in a 1020 tray to release the soil blocks.
   • Repeat this process until you have created the desired number of soil blocks for your seeds.
4. Sow Seeds
   • Place 1-2 seeds into each indentation according to the planting instructions for the specific seeds you are using.
   • Lightly cover the seeds with a thin layer of soil mix or vermiculite.
5. Water and Care
   • Water the soil blocks gently using a fine mist sprayer until they are evenly moist.
   • Place the tray with the soil blocks in a warm, well-lit location.
   • Monitor the soil blocks regularly and ensure they remain evenly moist, but not waterlogged, throughout the germination and seedling stage.
   • Begin by moistening the potting mix until it reaches a consistency similar to that of damp sponge. It should hold together when squeezed but not be overly wet.

Overall, using soil blocks for starting seeds is a sustainable, cost-effective, and efficient method that promotes healthier plant growth while minimizing environmental impact. Whether you’re a seasoned gardener or just starting out, incorporating soil blocks into your seed-starting routine can lead to more successful and rewarding gardening experiences.

More Gardening Content:

• How to Take a Seed Inventory
• How to Organize Your Seeds
• How to Start Seeds Indoors Without Grow Lights
• How to Start Sees Indoors Using Grow Lights
• The Best Seed Starting Supplies

SOme of our favorite places to order seeds:

• Baker Creek Heirloom Seeds
• High Mowing Organic Seeds
• Johnny’s Selected Seeds
• Osborne Quality Seeds

Some of oUr Favorite Gardening Books:

• The First-Time Gardener: Growing Vegetables: All the know-how and encouragement you need to grow – and fall in love with! – your brand new food garden by Jessica Sowards
• The New Organic Grower, 3rd Edition: A Master’s Manual of Tools and Techniques for the Home and Market Gardener by Eliot Coleman
• The Tiny But Mighty Farm: Cultivating High Yields, Community, and Self-Sufficiency from a Home Farm – Start growing food today – Meet the best … yourself, your family, and your neighbors by Jill Ragan