Growing plants from seed brings out everyone’s nurturing side and is about as close to magic as we can get. More pragmatically, starting seeds indoors lengthens the growing season, provides a pest-free growing atmosphere, saves money, guarantees that plants are grown chemical-free, and allows you to choose from a huge selection of seeds. If you work quickly, you can still grow plants for this year.

Figure 1: Fill and level containers and lightly compact.	Figure 2: Sow fine seed by pressing lightly onto surface; larger seeds may be buried approximately three times their thickness.
Figure 3: Cover surface with fine grit, then water from below and place in warm spot.	Figure 4: After germination, remove plastic covering and provide 14 to 16 hours of light per day.
Figure 5: The light setup, placed two inches above seedlings.
	Figure 6: Gently prick out larger seedlings once true leaves form and before roots become knotted, and pot separately. Take care not to damage fragile stems and roots.

Although some seeds demand very specific conditions to germinate, most are straightforward. To start plants indoors you will need sterile seed compost, clean and dry planting containers, labels, warmth, and light.

Peat discs are a cheap and convenient way to get seeds started, but peat is a strip-mined, non-renewable resource. Environmentally-friendly coconut coir (a byproduct of coconut husk processing) disks are also available, but starting seeds in pots or flats works just as well. Coir fiber may be mixed with equal parts of perlite and vermiculite to make a soilless planting compost.

If you only want to grow a few plants, sow seeds in individual pots to prevent any shock from transplanting. If your goal is to grow many, a flat may be your best bet. Either way, after filling pots or trays to the brim, level and slightly compact the compost by pressing with a flat object or by dropping the tray or pot gently onto the work surface (Figure 1).

Sow fine seeds on top of the compost as thinly and evenly as possible, and lightly press them in. Bigger seeds, like sunflowers, should be buried about three times their thickness or whatever the seed packet suggests (Figure 2). Cover sown seeds with a sprinkling of fine grit, which mimics natural conditions by providing sharp drainage while maintaining moisture under the surface (Figure 3).

Initially, rather than watering from overhead, stand pots or trays in shallow water. When the grit on top is damp, drain them and place in a warm place for germination. Dome covers and plastic bags are great for retaining moisture, but beware: the extra heat and moisture inside encourages “damping off” disease, an often fatal disease of seedlings (see sidebars). When using plastic covers, watch for excess moisture and remove the cover frequently to allow excess moisture to escape. After the seedlings have sprouted, discontinue using the cover (Figure 4).

At the first sign of sprouting, move the uncovered containers to a bright spot, such as beneath a couple of ordinary fluorescent shop lights (Figure 5). Windowsills generally aren’t adequate in the North because seedlings need a steady source of high-intensity light, 14 to 16 hours a day. If plants have to stretch or lean too much toward the light, they can become weak and spindly, so suspend the lights just two inches above the plants and gradually raise them as the seedlings mature. For consistency, hook the lights up to an electric timer. Seedlings don’t need as much warmth as germinating seeds, so keep them well ventilated and away from heaters.

Once the first true pair of leaves forms, prick out seedlings and pot up separately. First, knock the seed tray to loosen the compost and separate it from the pot or tray. If roots are extensive, they may need to be pulled apart by gently pulling on the expendable cotyledon leaves (Figure 6). Never pull seedlings by their fragile stems. Well-spaced seedlings can be gently lifted from the compost with a chopstick or something similar. Place them into individual pots, cells, or modules where they can grow without competition. When the time comes for a bigger pot, that transfer will be easy.

Only after separated seedlings are well-established should they be gradually introduced to the outdoors, a process known as “hardening off.” To do this, bring them outside and place them in a sheltered, partially sunny spot for a few hours each day, gradually increasing the length of their exposure and the amount of full sun over a week or two.

Eileen Stark is owner of Second Nature Garden Design, which offers sustainable design in the Portland area. She can be reached at 503-467-8545 or sngd@comcast.net.