If you’re planning on starting your own garden seeds this year, there are a few things you should know.
Plastic containers, like the six-packs you buy from your local nursery, will retain moisture better than coir (coconut husk) or fiber pots, because the latter wick moisture away from plant roots. If you’ve bought a soil block kit, that requires quite a bit of practice and experimentation with planting soil to get units to hold together.
There are flat black plastic “heat mats” — all apparently made by the same manufacturer — on the market. Everyone sells the same thing. Vendors may hate me for this, but I strongly dislike those “heat” mats. After several hours of charging, I still could not feel heat, so I returned it for a refund. Tomato and chile seeds germinate best at 80 degrees, I’ve found, and those mats don’t approach that heat.
Please don’t use heating pads or electric blankets for heat; they’re not designed for use day after day. Some people use heat mats designed for shoats (baby pigs) or for dog beds, and those should be OK and water resistant. Others use the top of the refrigerator or water heater, or a rack set above a furnace vent.
Plant in sterile potting soil, the bag of which has been closed to bar flying insects from laying eggs in it. I use six-pack cells filled with potting mix in web-bottomed flats, and prefer to bottom water, setting flats in a concrete mixing tub of tepid water. Once all sections are soaked, then I plant seeds in the wetted mix.
It’s very difficult to plant an eighth inch deep, so I lay seeds on top and cover them with potting soil or sand sifted through my fist. Then I spritz with tepid water until the topping looks wet.
Seeds for hot chiles are often slow to germinate, but can be coaxed along by an overnight soak in one teaspoon saltpeter (potassium nitrate) dissolved in a quart of water. Once dissolved, you can distribute seeds to pudding cups and pour in the saltpeter water for soaking. Later, use this solution to water seedlings, if you like.
Another way to hold moisture for germination is to cover seeded pots with clear glass or plastic wrap. Watch closely, and if mold appears, remove the cover.
An unexpected hazard to newly-germinated seeds is “damping off,” when seedlings collapse at soil level and die. To prevent this, be sure your seedlings have adequate ventilation, and water them only with tepid chamomile tea. For the latter, use about a quart and a half of hot water, two chamomile tea bags, let steep, then cool.
Watering tiny seedlings with cold water is quite a shock to their tiny structures, and they may die.
You can plant seeds such as onions or other alliums rather thickly in small pots, and weeks later pry seedlings apart, trim tops and bottoms with scissors for transplanting out. We plant leeks in trenches or holes made with dibbles (chopsticks work), to grow the white part of the leek to maximum size.
You can tease apart roots of seedlings to an extent, but when faced with a thicket of emerging seedlings, you’re better off to use manicure scissors to cut grooves through the thicket. Cut off the primary leaves of seedlings, and the plant dies. Some seeds, such as that for Portulaca, are as fine as soot, so the seed company reports they’ve sold you a thousand seeds and you see only a pinchful, very difficult to spread out seeds.
Primary leaves for tomatoes and chiles (and many other plants) are opposite strap-like leaves on a small stalk. Wait for the true leaves to show before you transplant into a larger container.
To develop strong seedlings, especially of tomatoes and peppers, either train a fan on them or lightly scrape across their tops with an arched piece of paper. The more the seedlings move or rock back and forth, the stronger their main stalks will be.
Your seedlings are plant babies, so acclimate them gradually, over a period of days, to direct sun and breezes.
Margaret Lauterbach: melauter@earthlink.net or write to Gardening, The Idaho Statesman, P.O. Box 40, Boise, ID 83707
