Saturday, 24 April 2010

Dealing with Seedlings

by Sadge, at Firesign Farm
My seeds started last month are all up and growing. Seeds have different germination times, so I've never been a fan of the big nursery-sized seed starting trays or flats. My vegetable garden feeds the two of us, plus extras to give away to friends and neighbors. I scrounge, save and re-use the six-packs flowering annuals are usually sold in. Six of anything is usually enough for the early-start vegetables, and since the warm season stuff (tomatoes, peppers, chiles, eggplant, basil, and okra) will be inside through May (photo below taken yesterday morning - at least half the time, our April showers are snow), I need to make sure I have enough room under the lights for them to do well.

Many of my seeds are more than the optimum one-year old, too. Some hot peppers may only get planted every four to five years - the seeds harvested from the last few peppers in a ristra strung up to dry that long ago. Others are from packets now three, four, even more years old. Since we only need a few plants each year, I'd rather put a few more of the old seeds into each cell to ensure that I get enough germination, than buy new each year.

I don't know, but I think there must be some kind of sprouting hormone produced by germinating seeds that encourages other seeds to sprout. Even though everything gets the same treatment, quite often it seems that every seed in one cell sprouts, while the one right next to it has none. After labeling each six-pack, wetting everything down with chamomile tea, and putting a few seeds into each cell, the lot of them are then covered with a big piece of plastic to keep everything moist. When most of a six-pack have sprouted, it's moved from under the plastic to beneath the lights - a couple of old four-foot fluorescent shop lights.

When growing seedlings under lights, some sort of adjustable hanging system, or a decreasing series of blocks underneath the plants, is necessary. The lights need to be right down on top of the just-emerging seedlings - an inch away is best. As the plants grow, the lights need to be raised up, or plants lowered, just enough to give them room. Since the fluorescent tubes are cool to the touch, it's ok to let the plants grow right up against them before moving the light farther away. In the past, I've used a couple of ladderback chairs, with a plank across the seats for the plants, and moved my lights up the ladder as necessary. This year, with a nice work table across my guest room bed, I just moved the plants around on that, and hung the lights atop a couple of cinder blocks. I can add more blocks as needed. Plants grown under lights need more light time than those grown in sunlight, but it's also necessary that they have some complete dark time too. I have the lights on a timer - on at 7 a.m. and off at 10 p.m. The hardier seedlings (chard, cabbages, kales, other brassicas, and calendula) spend nicer days on a table outside, coming in each night to the kitchen counter.

Now that everything is up and growing, it's time to thin them out. The best time to to this is after the embryonic cotyledon leaves are fully extended, with the first true leaves just starting to show. In six-packs where every cell has growing plants, I snip the weakest and littlest plants off near the base, leaving only one strong plant per cell. Snipping is better than pulling the weaker ones out, as it doesn't disturb the roots of the one that's left. Where I have an empty cell, I use a regular table fork to dig between two strong seedlings in one cell, transplanting one of them to the empty cell. When transplanting such young and tender seedlings, don't handle them by the stem at all. Support the dug-out plant by the roots, and hold onto the cotyledon leaf to steady it into place as you gently tamp the dirt down over the roots.

Seeds contain everything needed to get plants up and growing, so no fertilizing is needed to start seeds. But since mine will be spending at least another month inside, after the first true leaves emerge I start adding a tiny bit of liquid fish emulsion to their water. I don't water from the top, not wanting to give any molds or fungus an excuse to attack my little seedlings. Maybe once a week, water is poured into the holding pans, only as much as they'll take up in a day, and a natural wicking action pulls it up into the cells. This makes the plants' roots grow deeper instead of staying near the surface. Next post (unless one of my co-writers beats me to it): potting up and hardening off.