How to Use a Soil Blocker and DIY Soil Mix


Why I Decided to Use a Soil Blocker

For years I have been putting off blocking my own soil for starting seeds. Amazing how hard it can be to actually change, even when you already believe in the potential of another way. That goes for a lot of things. Well, after being inspired by one of Elliot Coleman’s books maybe a dozen years ago, this became the season I actually did something about it.

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 Multi-functional Blocking Mix

I made a small batch of soil blocker mix about a month or so ago because I wanted it to age a little before I put it to use, and the first application was in a kokedama project Debbie was working on. It worked really well for that, so I thought it may actually work for its intended purpose. The soil blocker (a Ladbrooke Mini 4 from Green Planet Naturals) was delivered today, and I couldn’t help myself.

How to Use a Soil Blocker and DIY Soil Mix

Mix Some Save Some

I dumped a few inches of the soil blocker mix in a plastic tote and added enough water to give it the consistency of oatmeal. My “oatmeal” was a little runny, and I had to add a little more mix. Eventually I got it close. The saturated mix stood for a couple of hours before I started. Since the mix was pretty well dried out I thought it best to give the peat a little extra time to re-hydrate.

Pack it Tightly

As the directions recommended, I dipped the blocker in some water, then pushed it into the mix while giving a slight twist. The blocker allows water to squeeze out as you compress the fibrous mix, so I pushed down a couple of places to make sure it was full and well compressed.

Level The Bottom

When I thought it was probably full, I pulled it out of the mix and peeked at the bottom of the blocker to make sure it was packed. I knocked a little excess off to make sure the blocks would sit level.

Slowly Back Away

Before I ejected the soil blocks, I gave them a little squeeze against the tray. Then I eased the soil blocker off while squeezing the release. I was amazed when the first set came out extremely well! (Yes, I use a baking sheet to start plants.) It dawned on me as I got going that I was squeezing water out of the soil blocker and into the mix, and it got runny again. No problem, I just added a bit more mix. A lesson learned the easy way: don’t wet all of your blocking mix at the beginning because you’ll need to add dry mix as you work through the batch.

Go Seed Something

I have a little work to do to ensure uniformity, but I feel pretty good about the purchase already. I turned out 56 blocks (fourteen cycles) in about five minutes my first time out. The soil blocker cost around $30. It’s sturdily made and a very simple machine that should last forever.


The Soil Blocker Mix Recipe


A “part” was an old Monrovia 1 gallon can. I added the ingredients in the order listed, mixing thoroughly after each addition to get a thoroughly incorporated medium. My first batch was three courses of this recipe.

  • 3 parts peat moss
  • a handful of powdered dolomitic lime
  • 2 parts coarse vermiculite
  • 3 cups of E.B. Stone Sure Start
  • 1 part garden dirt (stone free)
  • 2 parts well done compost





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7 thoughts on “How to Use a Soil Blocker and DIY Soil Mix

  1. The recipe uses “parts” and then switches to ” cups” for the phosphate product. IF we didn’t use a gallon can for the part, would you still use “cups” to measure the phosphate ?

    I am new to your site and have never heard of ” Garden Phenology”. However, I was just thinking to myself this morning, ” Why is it to early to plant seeds if the weeds are coming up ?”. I guess it is kind of the same thing. I am about 8 weeks out from our last frost date so ” the books” say that I could plant some of the cool weather kale, etc. Funny how the garden doesn’t always seem to have read the same books that I have. : )

    1. Christie,
      Welcome and thanks for checking out our blog! I intentionally listed “cups” and “handful” on those items because it is such a small fraction of a part being used. To make the recipe more flexible I would say 1/4 part Sure Start and 1/8 part lime should work well.

      Your assessment of the phenology section is the reason I wanted to add it to the blog. Flexing planting time by several weeks in either direction can be a very successful strategy, but it helps if you let Mother Nature show you what her plan is and adapt accordingly. If the pattern seems to be early or late with everything you’re observing (weeds sprouting, birds migrating, etc.) you should probably follow their lead. Eventually you will recognize specific triggers for individual gardening tasks in your area. I included the moon phase because there are lots of gardeners who plant “below ground” crops (onions, potatoes…) in the waning phases, and “above ground” crops in the waxing phases. It’s something to consider if you haven’t explored these things.

      Thank you for your questions and comments!

      Mark (via Debbie’s account)

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