I decided to switch from seed starting in peat pots to soil blocking for this years garden and have loved the transition.
Read more about why I switched and how soil blocking works.
This will be my third year planting a garden in Zone 6b, but my first year starting seeds with the soil blocking method.
Gardening has been quite the learning experience. It’s both an art and a science, with so many possibilities. It’s always so amazing to see such a harvest come from just a few tiny seeds. The work in the garden begins long before the weather warms!
The point of starting seeds indoors is to get a jump on the growing season by transplanting established seedlings as early as possible, most often after the last frost of the year.
Not all seeds are best started indoors. Some are best to just direct sow right into the garden soil when the time is right.
Some examples of seeds I start indoors in late winter are tomatoes, peppers, greens, herbs, some flowers, and cruciferous veggies like broccoli, cauliflower, and kale.
Some seeds that I direct sow in the garden are carrots, beets, peas, beans. corn, squash, and some flowers.
I have my favorite varieties of each plant, but I’ll save that for another post.
Starting seeds requires just a few things
- Light: You don’t need a big greenhouse or garden workspace to start seeds by any means. Although I’d love a greenhouse someday, I just use the counter space in front of a big row of windows in my kitchen to grow seedlings and it works wonderfully. Seeds can even be started in areas without natural light by using light kits, which I’ve done before as well.
- Warmth: Most seeds will require a temperature above 68F to germinate. So a well lit space that’s not warm enough could really inhibit germination rate. Yet another reason I love starting my seeds in my kitchen – the house is temperature controlled so no need to provide an additional heat source. However, some people do use heating pads specifically for germinating seeds.
- Growing Medium – Starting seeds indoors is different than direct sowing into garden soil so it requires a lighter growing medium. Garden soil is heavy and compact, it doesn’t drain well or allow enough air in the small space of a soil block. Seed starting mix is something you can make on your own or purchase pre-made. I’ve done both and its really just a matter of how much time you have. This year I bought bags of organic, pre-made starting mix.
- Water – Watering seedlings is pretty simple on a small scale. If you just have a few trays, adding a bit of water to the bottom of the tray so it never dries out is the best way to go. I check my trays daily and water as needed. When we build a greenhouse I might look into an actual system for watering all the baby seedlings.
- Containers – this is where soil blocking comes in. Each seedling will need its own space. I’ve always used peat pots in the past but decided to try soil blocking this year, and thats’ what this post will cover!
What is soil blocking?
Soil blocking is a simple & sustainable method for starting seeds without using growing containers. The block serves as both the growing medium and the container.
Apparently this method is more popular in Europe. But I think its catching on here in the US because I’ve seen it done more and more in the last couple of years since I started gardening.
Soil blockers are relatively inexpensive. They can be bought in a smaller hand-held size like this one, or larger for starting seeds on a bigger scale.
This little $34 contraption has already paid for itself in its first year by saving me the costs of buying peat pots!
Does it work as well as using containers?
Since this is my first experience – I can’t give my total testimony just yet. But I will update the post throughout the growing season.
From what I’ve read, soil blocks are not only more efficient and easier to start, they establish much quicker once transplanted into the garden as well. Which makes sense since there’s no container to grow through.
In years past, filling little peat pots and transplanting them a few times into larger pots before the final transplant into the garden was very time consuming. I was able to make 4 trays of soil blocks in under 10 minutes. So its definitely a quicker process.
How to make soil blocks
First, you’ll need a soil blocker like in the picture above. Then, some sort of good growing medium (this is the potting soil I’m using this year) and a big container or space to work with. I just used a wheelbarrow which worked fine.
The potting soil needs to be soaked a few hours before starting. I don’t have exact ratios here. Just add enough water so that the soil can be compacted together and hold its shape. I added about 2.5 gallons (ish) to one 15 cubic ft. bag of potting soil. Then waited 2 hours before making my soil blocks.
I learned that you have to push really hard to get good, compacted blocks.
Once each compartment is full to the top, push the handle down to release the blocks into a tray.
Each little block will have an indent in the top for placing seeds
The kids loved helping with this
And once all the trays are lined with blocks, its time to plant seeds!
I recommend following the planting directions on each individual package for this part.
After seeds are planted, cover the trays with a plastic cover or some plastic wrap to keep moisture in, making sure there are some holes for ventilation. I let the kids poke random holes with toothpicks, they think its great.
After seedlings emerge, the plastic wrap or cover can be removed.
The seedlings need to be in a well lit place at this point.
Soil blocks are best watered from the bottom so they maintain their shape. A spray bottle can be used to mist from the top but that takes a long time! I just pour a bit of water into the bottom of the tray slowly, making sure my soil blocks don’t ever dry out.
Once the time is right, these little blocks of soil and their seedlings can be transplanted right into the garden. I’ll come back and update this post throughout the planting and growing season to share a little more on that process.
If you’ve experimented with soil blocking, I’d love to hear any thoughts or tips!