Starting Seeds at Home
Starting seeds indoors will give you earlier vegetables and
flowers, and your cultivar choices will be endless. The process of germination
may seem complex, but the act of seed planting is reassuringly simple. Just
take it step-by-step, and you’ll soon be presiding over a healthy crop of
seedlings.
Select your work area—a surface at a comfortable height and
close to a water supply where you’ll have room to spread things out. Assemble
your equipment: seed-starting containers, starting medium or soil mix, watering
can, labels, marking pen, and seed packets.
Choosing Containers
You can start seeds in almost any kind of container that
will hold 1 to 2 inches of starting medium and won’t become easily waterlogged.
Once seedlings form more roots and develop their true leaves, though, they grow
best in containers that provide more space for root growth and have holes for
drainage.
You can start seedlings in open flats, in individual
sections of a market pack, or in pots. Individual containers are preferable,
because the less you disturb tender roots, the better. Some containers, such as
peat pots, paper pots, and soil blocks, go right into the garden with the plant
during transplanting. Other pots must be slipped off the root ball before
planting.
Square or rectangular containers make better use of space
and provide more root area than round ones do. However, individual containers
dry out faster than open flats. Many gardeners start seeds in open flats and
transplant seedlings to individual containers after the first true leaves
unfold. Choose flats and containers to match the number and types of plants you
wish to grow and the space you have available.
Newspaper pots are perhaps the simplest DIY seed-starting containers. To make pots from newspaper, begin by cutting bands of
newspaper about twice as wide as the desired height of a pot (about 4 inches
wide for a 2-inch-high pot). Wrap a band around the lower half of a jar a few
times, and secure it with masking tape. Then form the bottom of the pot by creasing
and folding the paper in around the bottom of the jar. You can also put a piece
of tape across the pot bottom to hold it more securely in place. Slip the
newspaper pot off the jar. Set your pots in high-sided trays with their sides
touching. When you fill them with potting mix, they will support one another.
There are also commercial molds for making newspaper pots.Seed-Starting and Potting Mixes
Seeds contain enough nutrients to nourish themselves through
sprouting, so a seed-starting mix does not have to contain nutrients. It should
be free of weed seeds and toxic substances, hold moisture well, and provide
plenty of air spaces. Don’t use plain garden soil to start seedlings; it hardens
into a dense mass that delicate young roots can’t penetrate.
Some gardeners prefer to plant seeds directly in potting mix
and eliminate transplanting. Planting in large individual pots is ideal for
plants such as squash and melons that won’t grow well if their roots are
disturbed.
Moisten the planting mix before you fill your containers,
especially if it contains peat moss or milled sphagnum moss. Use warm water,
and allow the mix time to absorb it. When you squeeze a handful of mix it
should hold together and feel moist, but it shouldn't drip.
If you’re sowing directly in flats, first line the bottom
with a sheet of newspaper to keep soil from washing out. Scoop pre-moistened
planting medium into the containers or flats, and spread it out. Tap the filled
container on your work surface to settle the medium, and smooth the surface
with your hand. Don’t pack it down tightly.
Sowing Seeds
Space large seeds at least 1 inch apart, planting 2 or 3
seeds in each pot (snip off the weaker seedlings later). Plant medium-sized
seeds ½ to 1 inch apart, and tiny ones about ½ inch apart. If you’re sowing
only a few seeds, use your fingertips or tweezers to place them precisely. To
sprinkle seeds evenly, try one of these methods:
- Take a pinch of seeds between your thumb and forefinger and slowly rotate thumb against finger—try to release the seeds gradually while moving your hand over the container.
- Scatter seeds from a spoon.
- Sow seeds directly from the corner of the packet by tapping the packet gently to make the seeds drop out one by one.
- Mix fine seeds with dry sand, and scatter the mixture from a saltshaker.
To sow seeds in tiny furrows or rows, just make shallow ¼-
to ½-inch-deep depressions in the soil with a plant label or an old pencil.
Space the seeds along the bottom of the furrow.
Cover the seeds to a depth of three times their thickness by
carefully sprinkling them with light, dry potting soil or seed-starting medium.
Don’t cover seeds that need light to germinate (check the seed packet for
special germination requirements). Instead, gently pat the surface of the mix
so the seeds and mix have good contact.
Write a label for each kind of seed you plant and put it in
the flat or pot as soon as the seeds are planted, before any mix-ups occur.
Set the flats or pots in shallow containers of water and let
them soak until the surface of the planting medium looks moist. Or you can
gently mist the mix. If you water from the top, use a watering can with a rose
nozzle to get a gentle stream that won’t wash the seeds out of place.
Cover the container, using clear plastic or a floating row
cover for seeds that need light, or black plastic, damp newspaper, or burlap for
those that prefer the dark.
Finally, put the containers of planted seeds in a warm place
where you can check them daily. Unless the seeds need light to germinate, you
can save space the first few days by stacking flats. Just be sure the bottom of
a flat doesn't actually rest on the planting mix of the flat below. Check the
flats daily; unstack as soon as the seeds start to sprout. Keep the soil moist
but not waterlogged. As soon as you notice sprouts nudging above the soil
surface, expose the flat to light.
Sowing Timetable
To plan the best time to start seedlings indoors in spring,
you need to know the approximate date of the average last spring frost in your
area. Count back from that date the number of weeks indicated below to
determine the appropriate starting date for various crops. An asterisk (*)
indicates a cold-hardy plant that can be set out 4 to 6 weeks before the last
frost.
- 12 to 14 weeks: onions*, leeks*, chives*, pansies*, impatiens, and coleus
- 8 to 12 weeks: peppers, lettuce*, cabbage-family crops*, petunias, snapdragons*, alyssum*, and other hardy annual flowers
- 6 to 8 weeks: eggplants, tomatoes
- 5 to 6 weeks: zinnias, cockscombs (Celosia spp.), marigolds, other tender annuals
- 2 to 4 weeks: cucumbers, melons, okra, pumpkins, squash