Starting Seeds
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Many garden crops and flowers can be started from seed indoors before it's possible to plant them in the
garden. Starting seeds in a warm indoor environment is virtually indispensable for growing crops such as
tomatoes in our climate; once the weather outdoors is warm enough to plant seeds directly into the garden
soil, there wouldn't be enough of the growing season left for them to bear fruit. Many other plants that
could grow from seed to maturity within our growing season will benefit from the head start of germinating
in a controlled indoor environment as well.
garden. Starting seeds in a warm indoor environment is virtually indispensable for growing crops such as
tomatoes in our climate; once the weather outdoors is warm enough to plant seeds directly into the garden
soil, there wouldn't be enough of the growing season left for them to bear fruit. Many other plants that
could grow from seed to maturity within our growing season will benefit from the head start of germinating
in a controlled indoor environment as well.
Vegetables that do well started indoors and transplanted to the garden include tomatoes, peppers,
eggplants, pumpkins and squash, cucumbers, melons, cabbage, broccoli, and cauliflower. Most
herbs and annual and perennial bedding plants also do well this way.
eggplants, pumpkins and squash, cucumbers, melons, cabbage, broccoli, and cauliflower. Most
herbs and annual and perennial bedding plants also do well this way.
Planting medium
Pots or peat pellets
Planting trays
Humidity tent or dome
Seedling heat mat
Seeds
Water
Fertilizer
Grow light
Pots or peat pellets
Planting trays
Humidity tent or dome
Seedling heat mat
Seeds
Water
Fertilizer
Grow light
To start out, you'll need planting trays and either peat pellets or pots
and planting mix. A planting tray is just a shallow container, usually
plastic. It may either be open to hold plastic or biodegradable pots, or
divided into individual planting cells that can be filled with planting mix
without the need for pots. Some trays also come with humidity domes,
which are simply clear covers that prevent moisture loss during
germination and the tender early stages of seedling growth.
and planting mix. A planting tray is just a shallow container, usually
plastic. It may either be open to hold plastic or biodegradable pots, or
divided into individual planting cells that can be filled with planting mix
without the need for pots. Some trays also come with humidity domes,
which are simply clear covers that prevent moisture loss during
germination and the tender early stages of seedling growth.
After watering, plant seeds, a few to each pot or pellet. Seedlings can be thinned later. If you're using a
humidity dome, place it on the tray.
You can greatly speed up germination by using a seedling heat mat. The heat mat is an electrical device
that goes under the tray and warms the soil from below. We've used them ourselves, and have seen
impressive results, with seeds germinating in the low end of the range of "days to germination" listed on the
seed packet, or even less.
humidity dome, place it on the tray.
You can greatly speed up germination by using a seedling heat mat. The heat mat is an electrical device
that goes under the tray and warms the soil from below. We've used them ourselves, and have seen
impressive results, with seeds germinating in the low end of the range of "days to germination" listed on the
seed packet, or even less.
Arrange peat pellets or pots in the tray. If you're using pots or a tray with individual planting cells, fill them
with planting mix. Use potting soil or seed starting mix, which are lightweight and free of harmful microbes,
not garden soil. Add water to expand the peat pellets or moisten the potting soil. Doing this before planting
will avoid washing out the seeds. The pellets or planting mix should be moist but not soggy.
with planting mix. Use potting soil or seed starting mix, which are lightweight and free of harmful microbes,
not garden soil. Add water to expand the peat pellets or moisten the potting soil. Doing this before planting
will avoid washing out the seeds. The pellets or planting mix should be moist but not soggy.
When starting seeds, use either a general-purpose potting soil or a
seed starting mix. These are light and porous enough to allow water
and air to penetrate to the seed, and free of disease organisms.
Pots come in different sizes and shapes, and are made either of plastic
or of a biodegradable material (peat or coconut fiber are common.)
Plastic pots may be reused if they are cleaned and disinfected by
washing with a bleach solution. Plants in biodegradable pots can be
placed in the ground pot and all when the time comes to plant them
outdoors.
Peat pellets are small, hard disks of peat bound up in a biodegradable
mesh cover that holds them together. When they absorb water, they
expand to several times their original thickness, and serve as both
biodegradable pot and planting medium all in one.
seed starting mix. These are light and porous enough to allow water
and air to penetrate to the seed, and free of disease organisms.
Pots come in different sizes and shapes, and are made either of plastic
or of a biodegradable material (peat or coconut fiber are common.)
Plastic pots may be reused if they are cleaned and disinfected by
washing with a bleach solution. Plants in biodegradable pots can be
placed in the ground pot and all when the time comes to plant them
outdoors.
Peat pellets are small, hard disks of peat bound up in a biodegradable
mesh cover that holds them together. When they absorb water, they
expand to several times their original thickness, and serve as both
biodegradable pot and planting medium all in one.
It's a good idea to turn on the grow light even before the seedlings start poking up from the soil. Unless you
have a very sunny window location for starting seeds, you'll definitely want to give your seedlings some extra
artificial light. An ordinary fluorescent light is better than none at all, but a grow light that mimics the full
spectrum of natural sunlight is best.
Once the seedlings have germinated, remove the humidity dome. Leaving it on too long will invite fungal
diseases which can quickly kill off your new seedlings. The heat mat can be turned off now, too.
have a very sunny window location for starting seeds, you'll definitely want to give your seedlings some extra
artificial light. An ordinary fluorescent light is better than none at all, but a grow light that mimics the full
spectrum of natural sunlight is best.
Once the seedlings have germinated, remove the humidity dome. Leaving it on too long will invite fungal
diseases which can quickly kill off your new seedlings. The heat mat can be turned off now, too.
Now the major needs of the seedlings are light, water, and nutrients, in that order. Seedlings should get 12 -
14 hours of light each day. Supplement natural sunlight with artificial light to make sure that your growing
plants get enough hours at the right intensity.
Keep the planting mix moist but not soggy, and don't let it dry out all the way.
Fertilize with a plant food labeled for seedlings, or a regular fertilizer at half-strength. You can use either a
synthetic or organic fertilizer. You can give them another application later if they show signs of nutrient
deficiencies.
14 hours of light each day. Supplement natural sunlight with artificial light to make sure that your growing
plants get enough hours at the right intensity.
Keep the planting mix moist but not soggy, and don't let it dry out all the way.
Fertilize with a plant food labeled for seedlings, or a regular fertilizer at half-strength. You can use either a
synthetic or organic fertilizer. You can give them another application later if they show signs of nutrient
deficiencies.
As your seedlings grow, they may become too big for their pots or cells. Their roots expand to fill all the
available growing medium, and the small amount of moisture it holds isn't enough for its growing foliage. At
this point, they need to be moved to a home with more room to grow. Some plants, such as cabbage,
cauliflower, broccoli, and lettuce, may not need to be transplanted until they're ready for the garden. Others,
however, such as tomatoes, peppers, and squash, may need another transitional home before they're strong
enough, and the weather is warm enough, for them to thrive in the garden. Upgrade to four-inch pots, using
all the potting mix or peat from the original container, plus enough to finish filling the new one. Water
thoroughly, and give them an application of fertilizer to get their roots growing again.
available growing medium, and the small amount of moisture it holds isn't enough for its growing foliage. At
this point, they need to be moved to a home with more room to grow. Some plants, such as cabbage,
cauliflower, broccoli, and lettuce, may not need to be transplanted until they're ready for the garden. Others,
however, such as tomatoes, peppers, and squash, may need another transitional home before they're strong
enough, and the weather is warm enough, for them to thrive in the garden. Upgrade to four-inch pots, using
all the potting mix or peat from the original container, plus enough to finish filling the new one. Water
thoroughly, and give them an application of fertilizer to get their roots growing again.
Soon the weather and the soil in your garden will become warm enough to plant your starts in the garden.
Before they're ready to be permanently planted outside the warm, safe confines of your house or
greenhouse, though, they'll need to be acclimated to the harsher climate outside. This process is called
hardening off.
Even before you start thinking about putting your starts in the garden, you can begin the hardening off
process by running a fan near them for short times during the day. This simulates the breezes outside, and
makes the plants develop sturdy but supple stalks that can sway in the wind without snapping. This is
especially important for taller plants like tomatoes, peppers, and eggplants.
On warm days, put the starts outside for a few hours during the day to acclimate them to the outdoor climate.
Keep a fairly close eye on them at first; starts that have been raised indoors under artificial light or subdued
sunlight can easily be sunburned. It's a good idea not to put them in full direct sunlight for a few days,
instead letting them acclimate in indirect sun or partial shade at first. Bring them back inside before the sun
goes down, and if the weather takes a turn for the worse during the day. After about a week, they should be
sufficiently hardened to plant outdoors.
Before they're ready to be permanently planted outside the warm, safe confines of your house or
greenhouse, though, they'll need to be acclimated to the harsher climate outside. This process is called
hardening off.
Even before you start thinking about putting your starts in the garden, you can begin the hardening off
process by running a fan near them for short times during the day. This simulates the breezes outside, and
makes the plants develop sturdy but supple stalks that can sway in the wind without snapping. This is
especially important for taller plants like tomatoes, peppers, and eggplants.
On warm days, put the starts outside for a few hours during the day to acclimate them to the outdoor climate.
Keep a fairly close eye on them at first; starts that have been raised indoors under artificial light or subdued
sunlight can easily be sunburned. It's a good idea not to put them in full direct sunlight for a few days,
instead letting them acclimate in indirect sun or partial shade at first. Bring them back inside before the sun
goes down, and if the weather takes a turn for the worse during the day. After about a week, they should be
sufficiently hardened to plant outdoors.
| Materials |
Hardening Off
Transplanting