Seed starting: preliminary results

Last week, I outlined the new system that Brian and I are planning to use to start this year's seedlings: a layer of ordinary garden soil, baked to sterilize it, underneath a layer of commercial seed-starting mix. This is the latest refinement to our existing seed-starting system, with tubes of PVC pipe for the seedlings, packed into juice cartons and kept under a DIY grow light. Now, after ten days and three batches of early seedlings, I can give at least a preliminary report on the success of the system. And so far, the results are encouraging. Take a look at these:

Those are the parsley seedlings, which we started twelve days ago. It may seem like overkill to start them quite so early, but most years, it takes them weeks even to germinate, and they're still pretty tiny by the time they go out into the garden in April. But this year, we've already got seven little sprouts up, all green and healthy.

We had even faster results with the broccolini, which got started just five days ago. This is the first year we've tried growing this crop, so I relied on the advice from Square Foot Gardening as to when to start broccoli seedlings. But now I'm wondering whether I was actually a little too early, because here they are already:

The third crop to get started was the leeks, which always require a very long lead time to produce healthy shoots for transplanting. These can be planted pretty thickly, so we always start a whole bunch of them, but Brian decided to do just a dozen or so with what he had left of his first batch of sterilized dirt, and then start the rest once he'd had a chance to bake some more. The second batch hasn't even been started yet, but already, two of the seeds in that first batch are starting to poke their little green heads out of the soil.

Since there are now actual green shoots rather than just sleeping seeds, we've set them out under the grow light, and we've covered them up with the cut-off tops of clear plastic egg cartons to help hold in warmth and moisture. (Brian further refined this part of the system by cutting the egg carton lids crosswise and overlapping the two halves to provide a snugger fit over top of the juice cartons, so less moisture can escape.)

So at first blush, at least, our new seed-starting mix appears to be a rousing success. Of course, it's too early to say for sure how the seedlings will fare in the long run; it's possible that they've started off beautifully, but the baked dirt won't end up providing enough nutrition for them to grow big and strong. But just having them sprouted at this early stage is definitely a promising start.

Brian has already baked up a second batch of dirt, so the rest of the leeks can go in this weekend. Then we'll have a hiatus of about a month before the really big planting of Brussels sprouts, tomatoes, and marigolds, which will really be the make-or-break test for this seed-starting system. Everyone keep your green thumbs crossed.