By Jennifer Langille
When it comes to growing plants from seed, there are many methods and techniques to explore. One that has transformed my indoor seed starting process is soil blocking.
It’s been a journey of trial, error, and success that has forever changed how I start seeds. Here’s a look at what soil blocking is, why I love it, and why it might be worth considering for your own garden.
What Is Soil Blocking?
Soil blocking is a method of starting seeds indoors without the use of traditional plastic pots. Instead, you create blocks of soil that hold the seeds and offer a strong foundation for healthy seedlings. The blocks are formed using a tool called a soil blocker, which compresses soil into small, individual blocks. The beauty of this method lies in its simplicity and effectiveness, with no need for single-use plastic containers.
Why Soil Blocking Works
I’ll admit, it took a few tries (okay, a lot of tries!) before I got the hang of it. But once I did, I saw why it’s become a go-to technique for gardeners, especially those looking for an eco-friendly, space-saving way to start seeds. All your resources go a long way. Here’s how:
- Saves Space: Soil blocks can be arranged tightly together, maximizing space without sacrificing seedling health. As of this writing, I have over 500 seedlings growing on just a standard household shelving unit in my basement.
- Uses Less Soil: Compared to traditional pots, soil blocks require much less soil, making them a more sustainable and economical option for gardeners. Save money on soil so you can buy more seeds!!
- Creates Stronger Seedlings: Soil blocks allow for better root development, as they “air prune” the roots because of the small air space between each block. When transplanted, soil-blocked seedlings’ roots establish themselves three days sooner than container grown seedlings. Healthy roots lead to stronger, more vigorous plants later on.
Why It’s Not for the Faint of Heart
While soil blocking offers numerous benefits, it’s not without its challenges. Creating the right consistency of soil, making sure the blocks hold together properly, and getting the right moisture levels are all things you’ll need to practice. There were definitely moments when I felt like giving up, but that’s part of the beauty of gardening.
Now that I have gotten the hang of it, though, I wouldn’t start seeds any other way. It’s an incredibly satisfying process that has made my seed starting more productive and sustainable.
Getting Started with Soil Blocking
If you’re interested in trying soil blocking, here’s a quick guide to get you started:
- Choose the Right Soil: A good, well-draining seed-starting mix is key. You can buy pre-made mixes or make your own, and it should always be sifted. There are lots of “recipes” online. The soil should be quite wet, like the consistency of brownie batter. .
2. Get the Right Tools: The soil blocker is a tool that presses soil into blocks. There are different sizes available depending on your needs. The North Shore Garden Club raised funds to purchase soil blockers and they are available to borrow from the Tatamagouche Library. Before I made the investment, I borrowed these soil blockers to practice and be sure it was for me. Once you buy it, you have it forever.
3. Press the Blocks: Press the blocker firmly into the soil and rock it side to side and back and forth to fill the blocks. You’ll want to make sure the blocks are compact enough to hold together but not so dense that they’re waterlogged. Squeeze the springed plunger to release the blocks onto your tray. This takes practice – don’t get discouraged!
- Plant Your Seeds: Once your blocks are ready, plant your seeds as you would in a traditional container. For tiny seeds, many find it easy to use the moistened tip of a toothpick to pick up and transfer the seeds into the blocks. Make sure to water gently from the corner of the tray and keep the blocks moist.
5. Watch Them Grow: As the seedlings grow, you’ll notice strong, healthy roots and sturdy plants. Fertilize, harden off and transplant as you would any other seedling.
Final Thoughts
Soil blocking has changed the way I start my seeds, and I’m grateful I stuck with it through the learning curve. It’s a great, space-saving way to grow healthy seedlings that will thrive in your garden. If you’re ready to give it a try, remember—practice makes perfect. Don’t be discouraged if things don’t go perfectly at first. Like any gardening method, it takes time and patience.
Happy gardening, and may your seedlings thrive in their new soil-block homes!
April 2025