This is a really fuzzy photo of a flat of seedlings sitting on the windowsill here at the office. Last Saturday, I sowed tomatoes (purple calabash from J.L. Hudson, Franchi yellow Pomodoro, and Baker Creek "Tigerellas"), peppers (purple cayenne, Baker Creek), and Holy Basil (J.L. Hudson). These guys had to spend a night in my not-so-warm bathroom before I brought them into work, so hopefully they germinate; provided they do, I'll post pictures of their progress and talk about how to take care of seedlings before you stick them in the ground.
Starting seedlings is really easy. You can get everything you need with one quick trip to a big box home and garden store. Or you can commit yourself to a slightly more complicated (but cheaper and probably more rewarding) process that includes making your own planting mix, planting in egg cartons and yogurt cups, and buying heirloom seeds through a mail order catalog. (For our roundup of seed catalogs, click here.) This post is aimed at beginning gardeners, so we're going to describe the simplest possible method of growing seedlings.
Most big box stores carry seedling greenhouse kits. Amusingly enough, Home Depot gives a seedling tutorial using egg cartons as the planting container! That's definitely cheaper, though you can get all kinds of bacterial and fungal problems with a dirty container, so be aware of that. (Yogurt cups and styrofoam or plastic egg cartons can be sterilized in a 10 percent bleach solution.) Starting with a greenhouse kit gives you the benefit of knowing your container is sterile. Also, you don't have to spill planting mix all over your table or floor - each cell has a little disc in it that expands in water, and you just pop the seed right in. Some are self-watering, with a mat under the cells that wicks moisture up to the plants' roots, which is a fantastic thing. If you care about your soil mix being sustainable, note that coir (made from shredded coconut shells) is much better than peat (which is harvested from bogs, and is not an easily renewable resource).
When buying seeds, check the back of the package for spacing requirements, and make sure you have enough room to grow the plant, not to mention adequate sun exposure—most vegetables require 6-8 hours of direct sun each day. Also ask yourself whether you'll actually want to eat what you're planning to grow. If you're not buying new seed, check the expiration date; after a year or two, your germination rate will go way, way down.
You can grow seedlings on a sunny windowsill, but they may get leggy (and exposure to a cold windowsill at night can damage your seedlings, not to mention make them more susceptible to fungi and bacteria). The best way to make sure you end up with healthy, stocky little plants is to use artificial lighting. The fancy gro-light setups can cost hundreds of dollars, but you can make do with a shop light outfitted with a full-spectrum florescent light of at least 75 watts. You can buy the fixture and the bulbs for about $15 at the same big boxes that carry greenhouse kits. You'll need a good solid bookcase to attach it to, but this means you can put your seedlings in a basement (provided it's not too cold, moldy or damp), and not have them taking up room in your actual living space. Shop lights come with chains, and you want to get the light as close to the seed as possible, and then ratchet up the chain as the seedling grows. Right now, I don't have the space to do shop lights, and many other people out there don't either, so our pilot seedlings will be raised in an office window.
Once you have everything ready—your greenhouse, your seeds, and your lighting setup—be sure to wash your hands well, especially if you smoke, because tobacco mosaic virus can travel from a smoker's hands to soil or seeds. (Gross but true.) The back of your seed packet should give you a germination rate for your seeds, and you'll want to use that as a guide to how many seeds to drop in each planting cell. Note that at some point, you'll have to harden your heart and weed out all but the healthiest seedlings.
And then you just plant your seeds, stick them under the light, and wait for them to sprout. Your seed packet will tell you how many days your seeds should take to germinate, so you'll know when it's time to start worrying you did something wrong because they're not growing. Also very important: once those little guys start to sprout, be sure to take the clear plastic lid off your greenhouse...otherwise, you'll have a fiesta of mold and mildew in your planting cells.
Of course, it's great not to depend on a prepackaged planting setup that is made mostly of plastic. I see it as a way to get new gardeners started. Once you get the hang of starting plants from seed (and you decide you like gardening enough to keep doing it), you'll probably want to find cheaper, easier methods that give you more control, like making your own soil mix, or saving your own seeds.
Next week—provided these seeds begin to sprout!—we'll talk about a plant's first true leaves, how much to water, and troubleshooting problems with new seedlings.