I’ve been starting some seeds lately, using whatever containers i could find to fill with some potting mix. One of the draw-backs of using whatever you find is that you can go through quite a bit of soil mix filling those containers, and end up wasting a lot of it with needless depth.
I wanted to start using soil blocks again so that i could maximize my seed germinating mix (a 2″x 2″ block of soil is a very efficient way to get plants started) and also i wanted to have more viable transplants (individual blocks of plants transplant better than plants torn from a communal pot).
Normally for soil blocks I would just repurpose plastic trays (bread or soft-drink ones). I’ve found that the bread trays can be very unwieldy when fully loaded with soil blocks. And not having anymore soft-drink trays left, I decided to build a couple of trays from off the shelf lumber material and see what came of it. Of course, these trays could be made with used lumber, but i didn’t find any free lumber on craigslist and i wanted to get seeds planted as soon as possible.
Supplies:
1 box 1″1/4″ wood screws
wood glue
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| 2″ soil blocker |
This Ladbrooke Soil Blocker measures 2″ wide and 7.5″ long (the forms are more like 2″x 1.75″, but not quite 2×2). I cut the fence boards at 23″ long, connecting them together with two pieces of redwood rough board (11″ long, miter cut to 45 degree angles). These 11″ pieces correspond to the width of the two fence boards put together. I glued and clamped the pieces in place and then screwed them in. I then proceeded to mitre cut two more pieces of redwood rough board at 23″. These two pieces were then glued and screwed into place along the edges of the fence board, creating the framed finish.
Redwood rough board is listed as 2″x 2″, but is actually only about an inch and a half. This gives us a surface area of 20″x 8″ within the frame to put our soil blocks (subtracting the width of the trim pieces from all sides).
From the material listed above and the dimensions indicated i was able to make 3 trays that hold approximately 40 soil blocks each. The third tray was a bit patch work as you can see, but there was hardly any material wasted, a couple of very small pieces from the mitre cuts. (I did cut off the dog ears from each of the fence boards at the beginning).
I added some plastic that was lying around to it at the end to give it some extra protection. Secured with a duct tape batting that is stapled through. We’ll see how they hold up. Soil blocks are notorious for getting dry fairly quickly. The tight spacing and plastic may help with that.
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| close up of soil blocks |
Looking ahead, i can see added thin wire hoops to these trays and pulling some repurposed, recycled bags over the top and creating a mini greenhouse; adding wood to the sides so that the trays can be stacked without damaging seedlings. I used a bagged potting mix as an experiment to see how well they hold up. There’s soil block recipes out there that can be used, which i may revisit. Ideally it would be great to come up with a recipe that doesn’t require buying bags of stuff, especially peat moss (can be too acidic for plants)
Shoshin Ecological Farming and Gardening 