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Starting From Seed
The Natural Gardening Company Method
This primer is based on the steps we follow when starting plants from seed in the Natural Gardening Company greenhouse. Each year, for many years, we have grown more than 200 varieties of vegetables, herbs and flowers. The method described here is the result of these years of trial and error, based on steps we have found give us good results.
Use good seeds
Good results begin with good seeds. Get to know suppliers whose seeds are dependable, and take good care of the seeds after you receive them. We keep our seeds in ziploc bags and date the bags so we know the age of the seeds. We also put desiccant in the bags whenever possible to keep the contents as dry as possible. Store your seeds in shady locations, away from heat and freezing temperatures. Direct light, extremes of temperature, and moisture quickly ruin seed quality. If we begin to get poor germination results with a particular seed lot we discard the seeds rather than waste time, soil, and greenhouse space on spotty germination.
Use professional quality propagation trays
Use a soil mix designed for starting seeds
It took us a long time to develop a soil mix that worked to our satisfaction. Poor mixes yield poor results. A good seed starting mix holds moisture, drains well, and is fine-textured. The latter is important because large particles in a seed starting mix will suppress seed germination. On the other hand, a seed mix that is made exclusively of fine materials will clog and drain poorly which causes seeds to rot. If you are making your own soil we recommend putting together a mix that is 1/2 peat moss to anchor roots and 1/2 vermiculite for aeration and drainage. To these two basic ingredients we add oyster shell lime (or any locally available source of calcium for pH adjustment) and blood meal, bone meal and kelp meal. You need to proportion these amendments in the mix at acceptable levels, i.e., read the labels and add accordingly. Too much is not necessarily better. Too much blood meal, for example, can burn young seedlings.
Select a location with as much light as possible
You will know immediately after your seeds germinate if there is sufficient light in the location you have selected. Seedlings that are white, long, leggy, and weak-looking are not getting enough light and need to be moved promptly. The best locations are sheltered areas outside on sunny decks and patios or inside greenhouses and cold frames. If you must start your seeds indoors and you rely on artificial light, place the lights very close to your propagation trays. If you are using fluorescent light fixtures place them within several inches of the top of the soil surface. This may seem too close, but it is not.
Most seeds germinate better when the soil is warm. In some cases it may be possible to heat the air in the area where you are starting seeds, but often it is more sensible to use a seed tray heater to heat the soil. Seed tray heaters will improve your results significantly, especially with tomatoes, peppers, and eggplants.
Don't cover small seeds with soil
For most perennials, vegetables, flowers, and herbs we place the seeds on the soil surface and press lightly with our thumb to insure good contact between the seed and the soil. That is all. You may be tempted to dust the seeds with a light layer of soil, but in our experience this inhibits seed germination. The only seeds we push beneath the soil surface are large: sunflowers, nasturtiums, peas, beans, squash, and pumpkins, for example.
Keep the soil moist
For best results monitor the progress of your seeds daily. Water when the surface of the soil is almost, but not completely dry. Drying out is the most common cause of seed failure. If the soil surface begins to develop green algae, you are keeping your seeds too moist. They may also not be getting enough light. If the surface of the soil forms a crust and begins to peel back, even with repeated watering, you may be growing in a location that is too hot. This can happen in fully exposed outdoor and greenhouse locations in the hot summer months. Move your trays to a location where the light is buffered to lower the air temperature, and where there is good air circulation.
If you are using a humidity dome on your propagation tray we recommend removing it after the seeds have come up. If it stays on longer the plants will become soft and succulent, or succumb to damping off. Exposure to circulating air makes a stronger transplant.
Transplant on time
If transplants stay in their trays too long it may permanently affect their growth. This is particularly true of annuals: vegetables, flowers and herbs. We try to move plugs of tomatoes, peppers, and eggplants when they have two sets of true leaves. If conditions are good you may have two weeks or more to hold them in plug form, but we have found the best results are achieved when we transplant early, rather than late.