Gardening with Soilblocks
by Richard Perkins
I bought myself a new garden tool for this summer’s vegetable garden. It’s a Ladbrooke soil blocker and it’s designed to simplify the process of raising plants from seeds. They’re manufactured in England, but you can buy them at a number of online resellers or make one yourself, if you’re up to the task.
The basic idea is to mix seed starting mix and water into a mud-pie-like consistency, pack it into the blocking tool to compress and form the blocks, than eject rows and rows of preformed blocks onto a tray or shallow dish. The tool imprints a perfect, seed-sized divot in the top of every block. you simply drop a seed (or two) into every divot, pinch closed, water regularly (and they do mean regularly) and put the trays in a sunny spot for a week or two. Once the seeds germinate and sprout their first true leaves, they’re ready to harden and transplant into your garden.
One major advantage of this approach is that you don’t have to thin out half or more of your seedlings on your hands and knees because you direct sowed your seeds too thickly. The only plants that go in the ground are the ones you want to keep. The trade-off is that you need some appreciable surface area to set out your soil blocks while you’re waiting for the seedlings to sprout. This might be tough for people without any greenhouse or sunny window space.
Here are some pictures that I took as I worked my way through the process. The first step was making the soil blocks. I used an organic seed starting compound that I mixed with a little vermiculite and peat moss. It took a little fine tuning before I got the mud-pie consistency right, but the neat little rows of soil blocks were fun to make. With the five block tool, you can amass an army of blocks very quickly, so don’t get too carried away!
Next I had to add the seeds. To sow the seeds, I used a trick that I picked up from David Tresemer’s excellent reference, Transplants in Soil Blocks. I dampened the tip of a bamboo skewer (I was out of toothpicks) and used it to pick up one seed at a time from the seed packets. Then I pressed each seed into the wet divot in each soil block (where it would stick without hesitation). You’d think it would be tedious work, but it went surprisingly quickly.
I then covered the seeds with a layer of dry vermiculite and potting soil (to prevent damping off when the shoots pushed up through it). I dispensed the seed cover with a folded piece of cardstock, being careful not to bury the seeds too deeply. With this many blocks, it could have been very easy to forget which plants were where. I created a map using the grid of a spreadsheet. It turned out to be a lifesaver later on, when I was trying to figure out which seeds had germinated and which I had lost.
The first sprouts appeared in about a week, and by the end of two weeks, most of the seedlings had emerged. Unfortunately, I lost a lot of this first batch because I kept them covered (to retain moisture) and out of the sun (to prevent overheating). About half of the shoots shot up thin and leggy from lack of light. Then when I moved the box out onto a shelf in outside our window, I didn’t water them often enough. Misting the blocks at least twice a day once the sprouts emerge is critical. Those little soil blocks may be cute, but they don’t hold much water. They’ll dry out pretty quickly in direct sunlight. I didn’t make the same mistakes on my next batch of seeds.
Today was the culmination of my soil blocking efforts. Today, after hardening the seedlings on the window shelf outside for the past week, I transplanted the hardiest of the lot to our little vegetable plot in the back yard. You can see the results below. I’ve got a couple zucchini plants, a couple rows of peppers, a row of bush beans, four kinds of tomatoes, some cilantro, some sweet basil, a row of rainbow chard (still running strong from the winter crop), and a few sunflowers in the back. The garlic is growing over in the other planter with the rose bushes this year. And I’ll probably plant some green onions and an eggplant or two if I can find the space. It’s too soon to tell how fruitful our little plot will be this year. I’m trying to grow everything in it from seed instead of using plants from the nursery. Hopefully (fingers crossed) this summer’s crop will be a tasty one!
