This was the year we dove head-first into seedling starting. Last year, we got our feet wet with early lettuce and spinach. This year, we took on a dozen more crops for a total of 350 seedlings! Here's what we did… and learned.
We started the seedlings in two main groups: early (sown on March 9th) and late (sown on March 30th).
Our early seedlings were Greens (lettuce & spinach), Alliums (leeks & onions) and Brassicas (broccoli, Brussels sprouts, cabbages & cauliflowers). They were first transplanted into 6-packs, then planted in the garden on April 21 (6 weeks after sowing). We had a long cold early spring followed by a heat wave, so the transplants took some time to take hold and have suffered some heat stress. Yet, we've had an excellent harvest of early greens and most of the alliums and brassicas have hung on and are now growing well.
Our late seedlings were the Nightshades (eggplants, peppers, tomatillos & tomatoes), along with okra, basil and a smaller, second crop of lettuces. They went into the garden on May 27th (8 weeks after sowing). Unlike the early seedlings, they required transplanting twice: first into 6-packs and then into 4-inch pots. The tomatillos and tomatoes may have been slightly overgrown (over a foot tall, some with flowers) when planted in the garden. The eggplants and peppers were strong, stunningly perfect 6-9 inch tall seedlings.
We experimented with sowing in soil blocks this year. The lettuces and spinach were planted directly into pressed soil blocks made with a press borrowed from fellow gardener, Donna Kray. It took some experimentation to get the soil consistency and moisture level right (quite heavy and wet). It also took some practice to perfect the pressing technique, but the seedlings did very well. The soil block presses come in graduated sizes – with the smaller ones fitting into the larger ones — so they could also be used for the late seedlings.
The seedlings that weren’t in soil blocks were transplanted into 6-packs 2 weeks after sowing. The late seedlings were transplanted into 4” pots after an additional 2-3 weeks of growth. We made our own planting mix of coir, sterilized compost, vermiculite and sand. Unlike mixes using peat moss, no lime was needed to neutralize the acidity. We increased the amount of compost and decreased the vermiculite in the mix each time the seedlings were transplanted, always making sure to include a sprinkling of organic fertilizer.
Our seedlings began indoors under lights. Three 4' dual fluorescent fixtures were suspended below the upper shelf of a sturdy 4' x 2' x 6' tall shelf unit. Three 18" x 24" trays holding the seedlings were slid in on the shelf below. Two of the bulbs were Ecolux T8 and the others were older Paralite grow lamps.
The lights were run through a simple timer, set for 15 hours a day. The distance of the seedlings from the lights was adjusted by the number of trays (these trays have a 3/4 inch thick rim) and by switching out varying length S hooks made from heavy gauge wire suspending the light fixtures.
The only way we could grow so many seedlings was with the coordinated efforts of our dedicated seedling committee (Lisa, Michael, Mike, Sue and me). We gathered for planting and transplanting sessions, and took on caring for the seedlings at different stages of their development.
The grow lights in our basement made it easy for me to oversee the sprouting and early stages of growth. When it came time for the seedlings to be hardened off and given real sun, Lisa, Michael and Sue took over their care. We were able to spread the work and all reap the rewards — awesome!