Prepare the Soil
Particularly in cold-winter areas, the biggest mistake a
gardener can make is starting the garden too early, when the
soil is still wet. Before preparing the soil in spring, squeeze
a handful of soil into a ball and drop it. If it breaks apart,
it is sufficiently dry. If not, wait a week and try again. Use a
rake to pulverize clods and create a fairly smooth surface. Soil
need not be flour-fine; marble-sized particles are okay.
Seeds germinate best in loose, well-drained soil that has enough
decayed organic matter help it hold moisture evenly. Because
organic matter breaks down continuously, regular additions of
compost or other good organic material are necessary. Turn
several inches into the top 8 inches of your garden soil.
at the Right Time:
Some Like it Hot (and others do not)
The majority of seeds germinate most quickly and successfully
when the when both day and night time temperatures have 50 to
55°F (10 to 13°C °.
In all US climate zones except the very warm areas, long season
heat loving tomatoes, peppers and eggplants must be started
early indoors so they have enough room to grow, mature and fruit
when you plant them outside.
Members of the cabbage family like broccoli, cauliflower, and
long growing vegetables like leeks and perennial herbs like
oregano and thyme may also be started indoors to get a head
start of the season. Consult the seed packets to see if this is
Be sure to use a good quality seed starting mix in your the seed
trays. After sowing, according to package directions, keep the
seed starting trays warm for best results. You can purchase a
heat mat designed specifically for this purpose, or place
seedling trays on top of a refrigerator, hot water heater,
radiator, or other warm surface. Make sure they are moved into
right light as soon as germination occurs.
TIPS FOR SUCCESSFUL INDOOR GERMINATION
1. Use a purchased seed starting mix rather than garden soil
for indoor seed starting.
2. Provide bottom heat if ambient temperature is less than
3. Place a cover over sown seeds to maintain even moisture.
Remove it as soon as germination occurs.
4. Test leftover seed before using it. Place 10 seeds
between layers of moist paper towels. If fewer than 7
germinate after a week, buy new seed.
Spring – Sow these seeds
directly into the garden bed:
Vegetables and Herbs: Arugula, Beets, Broccoli Raab,
Carrots, Chard, Chervil, Cilantro, Dill, Fennel (bulbing),
Kohlrabi, Kale, Lettuce, Mache, Scallions, Pak Choi,
Parsley, Parsnips, Peas, Radishes, Spinach, Salad
Greens, Spinach, Tatsoi, Turnips.
Flowers: Alyssum, Bells of Ireland, Calendula,
Cornflowers, Larkspur, Nigella, Poppies, Stock, Sweet
Start Indoors for a Head
Vegetables and Herbs: Basil, Broccoli, Cabbage,
Celeriac, Eggplant, Leeks, Peppers, Perennial Herbs,
Flowers: Columbine, Delphinium, Feverfew, Foxglove,
Globe Amaranth, Heliotrope, Hollyhock, Nicotiana,
Pansies, Perennial Flowers, Portulaca, Snapdragons,
Early Summer – Sow directly
into garden bed when nights stay
above 50°F (10°C):
Vegetables beans, beets, carrots, chard, corn,
cucumbers, melons, pak choi, okra, oregano, pumpkins,
salad greens, scallions, summer squash, including
zucchini, winter, savory squash, including zucchini,
melons and watermelon.
HERBS basil, oregano, marjoram, chamomile, sage, thyme
Flowers: Cardinal Climber, Cleome, Cosmos, Four O’Clocks,
Marigolds, Morning Glories, Nasturtiums, Nicotiana,
Nigella, Salvia, Sunflowers, Tithonia, Zinnias.
Sow in Mid-Summer-Early Fall
for 2nd (or in mild climates, overwintering) Crops:
Vegetables and Herbs: Arugula, Beets, Broccoli, Broccoli
Raab, Brussels Sprouts, Cabbage, Carrots, Chard,
Chervil, Cilantro, Fennel (bulbing), Kale, Kohlrabi,
Leeks, Lettuce, Mache, Pak Choi, Peas, Radishes, Salad
Greens, Scallions,Spinach, Tatsoi, Turnips.
Flowers: Alyssum, Calendula, Cornflowers, Foxglove,
Larkspur, Nigella, Pansies, Snapdragons, Stock,
(mild winters only) Sweet Peas.
Seed packets offer detailed instructions about depth of
planting and seed spacing and give you good tips on how to be
successful. The following are general guidelines:
• Depth of Planting: Large seeds such as beans and squash should
be planted 1 to 2 inches deep, while small seeds need only a
light covering of soil.
• Spacing: Pay close attention to spacing instructions,
especially when sowing directly in the garden. Small seeds like
lettuce and carrots should be no closer than 1 inch apart.
• Very small Seeds: Mix tiny, dust-like seeds with sand at about
a 4 to 1 ratio to avoid planting them too closely.
Germination is all about water. In order for plant cells to
start multiplying the dried seed must absorb several times its
volume of water, causing the embryo to enlarge and the seed coat
to burst open. If moisture is inconsistent, the developing
embryo will be stressed. Too much water can cause seeds to rot,
particularly when soil is cold. Check your germinating seeds
frequently, especially if they are exposed to wind or sun, and
try these tips for keeping the soil consistently moist:
• Temporary cover: Place row cover over the seed tray or garden
planting bed. Some gardeners use burlap. Check beneath the
covering daily and mist the soil if it begins to dry. Remove the
covering as soon as you see tiny stems pushing up from the soil.
• Retain moisture: Cover the row with a material that absorbs
and holds moisture, such as vermiculite, potting mix, or sieved
Provide Enough Light
All seedlings require ample light immediately following
germination. When starting seeds indoors there are several
• Sunny window: A south-facing window will suffice if you start
seeds in April, when the days are relatively long. Move the
seedlings outdoors on warm days, and in again at night, to
prepare them for outdoor living.
• Lights: Very early spring seed starting growing requires the
aid of fluorescent shop lights or grow lights. Suspend them on
chains, raising them as the seedlings grow. Keep them on for at
least 12-16 hours a day.
Word About "Thinning" & Why It's so Important
Sowing seed too closely is a common new seed gardener' s mistake
… we’ve all done it! Pulling out the tender seedlings you have
successfully germinated is not easy, but you’ll get more produce
from carefully spaced robust plants than from a crowd that is
forced to compete for water, nutrients, and sun.
Seed packet backs always provide you with both instructions on
how far apart to sow seeds and then how far apart to thin them
so that the remaining plant our space properly for optimum
growth and production. Be sure to consult them!
the event that your seedlings germinate in an intimate bunch,
here are a couple of pointers:
• Root Vegetables: Beets and radishes are particularly finicky
about having enough personal space. Thin radishes to stand about
1 inch apart. Beet seedlings should be at least 2 inches apart
initially. Baby beets can be harvested and eaten (the greens
too!) so that the remaining seedlings stand about 4 inches
• Carrots and turnips are also candidates for thinning. Wait
until the seedlings are about 2 inches tall and then ruthlessly
eliminate those that are excessively close to neighbors, giving
the roots the room they need to develop. For the least amount of
disturbance, thin with scissors.
• Leaf Vegetables: Lettuce, spinach, arugula, chard, and other
greens may also need thinning. In this case you have a choice.
You can use the thinnings in salads, or transplant them to
another part of your garden. To transplant, lift an entire
clump, gently teasing the roots apart. Replant a single
seedling, and move the others.
• Fruiting Vegetables: It is for good reason that zucchini seed
packages instruct you to thin seedlings to 2-3 plants per hill:
Crowding reduces air circulation, making your plants more
susceptible to disease.
Garden Seed Association (HGSA) |
P.O. Box 93, Maxwell, CA 95955 |
Phone (530) 438-2126 |