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Back to Basics: How to Start Seeds Indoors

Gardening is a wonderful pastime and filling your garden with plants you started yourself from seeds simply doubles the pleasure. If you think growing from seed is difficult and takes too much time and equipment, the steps and tips here will dispel those apprehensions. Basically all you need to know about specific seeds is whether or not they require light to germinate and the number of days germination takes. With a light garden or a very sunny window, a few containers-purchased or "found"-and a good germinating mix, you will be on your way.

The reasons for starting seeds indoors are many. For much of the country the growing season is too short to allow many annual plants that need warm soil and hot weather, such as tomatoes, peppers, petunias, and salvias, to mature and bear flowers or fruit if you sow them directly in the ground. Some plants produce very tiny seeds, which are easier to sow and care for indoors; begonia seeds, for example, are so fine they look almost like powder. And then there's the magic: Watching a seedling push up above the soil surface creates a bond between you and nature.

Materials You Need

Getting Started

  1. Wet the germinating mix thoroughly and let it drain. It should be moist but not soggy.
  2. Fill flats or individual pots with the mix to within about an inch of the top.
  3. Make shallow row indentations with a ruler or your finger in the flats. It's easier to separate seedlings when transplanting time comes if you sow in rows. Sow thinly so you do not waste seed. If using pots make shallow holes and set 3 to 4 seeds in each.
  4. Check the seed packet to see if the seeds need light to germinate. If they do, press them lightly into the surface. If they require darkness, cover with 1/4 to 1/2 inch of mix or vermiculite and tamp it down.
  5. Mist the surface with water to settle the seeds.
  6. Cover the flats with a sheet of plastic wrap or set them in plastic bags. Set pots in plastic bags and close with twist ties. This keeps the mix from drying out while the seeds germinate, but check the mix occasionally and moisten if necessary by spritzing with water.
  7. Place the flat in a warm, bright location or in a fluorescent-light garden. Check the seed packet for specific soil temperatures for germination. Generally, seeds germinate with soil temperatures of 70-75° F.
  8. When the seedlings emerge, remove the plastic covering. Seed packets give you an idea of germination time, usually 7 to 10 days, sometimes as long as 2 to 3 weeks.
  9. Keep the mix evenly moist, not soggy. Water from the bottom by setting flats and pots in a sink filled with a couple of inches of water; remove them when you see moisture on the surface of the mix.

Moving On

The first leaves on a seedling are cotyledons, not true leaves. Their shapes usually do not look like the plant's familiar leaves. When seedlings in flats grow at least two sets of true leaves, transplant them into pots.

  1. Moisten the transplanting mix and let it drain. If you use an all-purpose potting soil, add a handful of vermiculite for each quart of mix to lighten the texture.
  2. Fill 2-1/4-inch pots about three-quarters full.
  3. Use your fingers or a pencil to pick each seedling out of the flat, carefully holding each by the leaves not the stem. (Plants readily grow new leaves but not broken stems.)
  4. Set the transplant in the pot, filling in around the roots with more mix and firming the mix down.
  5. Place pots on a sunny-preferably south-facing-windowsill or in a light garden.

Growing Well

Let There Be Light

Many seeds germinate best-more quickly and more abundantly-if you do not cover them with a mix when you sow.










Oriental Poppy







A Few Do's

A Few Don'ts

Outdoor Preferences

Some plants resent being transplanted, but if your growing season is short, you can start them indoors in individual peat or paper pots, which biodegrade; set plant in its pot in the garden.

Annual Phlox









We wish to acknowledge Eleanor Lewis as the author and the National Garden Bureau