PREPARE THE SEEDS
When you soak seeds, you allow water to fully penetrate the hull of the seed, nourishing the germ that will bloom into a plant. Seeds will get food from the nutrients in the soil surrounding them once they are planted, but to flourish they need plenty of water. It can be difficult for seeds to take on adequate water once they are planted, because soil can wick moisture away from the seeds before the water fully penetrates the seed. Soaking seeds nips this problem in the bud, as it were, by offering your seeds as much water as the seeds can use and store.
Why Soaking Seeds Works
The short answer to why soaking seeds makes your seed sprout faster is that it fools your seed into thinking that it has been planted for longer. When you soak seeds, they take on the same amount of water in just a single day of soaking that would take the seeds up to a week to absorb if they were planted. Soaking seeds speeds up seed germination by making sure that your seeds get their thirst fully quenched before they are submerged in the ground. When they are fully soaked, the seeds behave as thought they've already been planted for days, or even weeks, before you have even put them in your garden. This radically shortens the overall timetable for seed germination.
To soak seeds, submerge them in warm water. The water should not be so hot that it is uncomfortable to the touch, as this can shock the seeds, but gentle warmth will help soften the hard outer hull so that water can penetrate the seed more easily. If you are working with seeds that have an extremely tough outer layer, such as Morning Glory seeds, it is a good idea to nick the hull of the seed before soaking. However, most seeds can be successfully soaked for fast germination without nicking or "scarring" the hull beforehand. Simply leave your seeds in at least three inches of water for twenty four hours, then check to see if they are ready to plant. If they look like fully soaked seeds as described in the following paragraph, you're finished. If not, add enough warm water to bring the water level back up to three inches, and leave the seeds there for another day.
What A Soaked Seed Looks Like
The appearance of the seed is the best way to tell when your seed soaking has achieved its goal and the seed is ready to plant in the ground. After you've left your seeds in water for twenty four hours, check on your soaking seeds and see how they look. When a seed has fully absorbed as much water as it needs, it will swell and lighten in color as the hull softens and the inner kernal of the seed absorbs water. When your seeds have swelled to a larger size, feel soft in texture, and appear a few shades lighter in color, it means that the water has fully penetrated the seed. Now, you are ready to plant your seeds, and enjoy fast germination in your garden!
Steps for Soaking Seeds
Sprinkle small seeds across a paper towel or coffee filter and thoroughly soak the seeds and surrounding material with water.
Wet a second piece of paper and place it over the first, covering the seeds.
Leave the seeds soaking for up to 12 hours, checking every hour to see when they begin to swell. Add more water to the seeds if the towel or filter dries out. Once the seeds appear to be approximately double in size, remove them from the towels and plant them according to package directions.
Scratch the surface of seeds that have hard casings with a small file or paring knife. This cuts through the layers of the tough outer coating to allow water to penetrate the seed and end the seeds' dormant phase. This only needs to be done at one location on the seed.
Place scratched seeds into a bowl of water for three to four hours prior to planting.
Treat stubborn seeds with acids such as sulphuric acid or gibberellic acid-3 (GA-3). Purchased through chemical supply companies or occasionally marketed through garden centers, the acid stimulates germination making it possible to grow seeds that would otherwise require prolonged or complex treatments. Seeds are soaked in the acid for 30 to 120 minutes, depending on size. Then the acid is washed away with water and planted. The timing is critical as overexposure will kill the seeds, therefore this method is not as common among amateur gardeners.
Distribute seeds that have been soaked for 24 go 36 hours evenly across a layer of peat moss to get sprouts started.
Transfer the peat moss to a plastic tub and place the tub in a refrigerator for four to six weeks, spraying with water as needed to keep the peat moss moist.
Use a combination of cold and moisture to encourage germination. If you have several months, this can be easily accomplished by placing the seeds into a plastic freezer bag with a damp paper towel and tossing them into the freezer for up to four months. The damp, cool conditions mimic winter, preparing the seeds to germinate when warmer conditions begin.
PLANT THE SEEDS
Moisten your medium in the containers before sowing the seeds. Next, drop seeds onto the surface of the mix, spacing them as evenly as possible. Cover the seeds to a depth about three times the thickness of the seeds.
Top it off
Lightly sprinkle milled sphagnum moss, a natural fungicide, over everything to protect against damping-off, a fungal disease that rots seeds and seedlings. In the case of seeds that need light to germinate, sprinkle the moss first and then drop the seeds onto the moss.
Keep seeds cozy
Cover the flats with plastic wrap or glass to keep the environment humid and place them near a heat vent or on a heat mat made especially for seed starting. Most seeds germinate well at about 70 degrees F.
Keep them damp
Mist with a spray bottle or set the trays into water so the mix wicks up the moisture from below.
WATER THE SEEDS
Vegetable seeds require moisture so they seed coat can split open and the young plant can absorb nutrients. Water your seeds only enough to keep the soil moist. If the soil gets too wet the seeds may rot. Allowing the soil dry out may prevent the seed from germinating or kill small seedlings.
Before you plant the seeds in the seed starting mix, moisten the mix with water to reach the right amount of moisture: damp, but not too soggy. That way you can plant the seeds exactly as the instructions say without disturbing them later with watering. Seeds need to be in contact with moisture in order to germinate, but too much water will kill your efforts.
To maintain the right level of moisture, cover the pots after planting with a sheet of clear plastic. The covering should not be sealed tight. You have many choices for containers – saved Styrofoam and yogurt cups work equally well as a seedling flat from the store, so long as you poke holes in the bottoms of the cups to give adequate drainage. You can even save fast-food salad containers with the clear plastic covering, but drill plenty of holes in the top and bottom, otherwise the seedlings will cook and drown.
Watering is only necessary when the soil is visibly dry and the seedlings are about to wilt. Some gardeners like to keep peat seedling pots in a tray for watering from the bottom up. They put the water in the tray, wait for the peat pots to soak up enough water so the top soil is moistened, then they drain the extra.
LIGHTING FOR THE SEEDLINGS
The hardest element to provide indoors is light. It is possible to start seeds in a room or on a windowsill that receives a full day (at least 8 hours) of bright light. At the first signs of sprouting, uncover and move the containers to a bright spot - a sunny window, a greenhouse, or beneath a couple of ordinary fluorescent shop lights (4-footers with two 40-watt bulbs).
Most gardeners will need to supplement their seedling lighting with special plant or grow lights that simulate the full spectrum of the sun. Even then, the lights will need to be left on for 12-15 hours per day, for your seedlings to grow as strong and healthy as they would in sunlight.
Your choice of plant lights depends on how many seedlings you're starting & the area you need to light. Choices range from single lamp bulbs on up to 1000 watt high intensity lights. You can set up a simple shop light system or purchase a ready-made, movable set-up.
Whatever system you choose, you should put your plant lights on a timer. Indoor lighting is less intense than sunlight & needs to be left on for 12-15 hours per day. A timer works better than your memory. Follow these guidelines to choose which plant light system is right for you.
The lights are worthwhile, especially if you live in the North. They provide a steady source of high-intensity light. Suspend the lights just 2 inches above the plants and gradually raise them as the seedlings mature. If plants have to stretch or lean toward the light, they can become weak and spindly. To turn the lights on and off at the same time each day, hook them up to an electric timer.
FOOD FOR THE SEEDLINGS
You can buy bags of seed-starter mix or you can make your own by blending equal parts of perlite, vermiculite, and peat. Add 1/4 teaspoon of lime to each gallon of mix to neutralize the acidity of the peat. You'll eventually want to repot most of your seedlings into larger containers before setting them into the garden. But lettuce, melons, and cucumbers are finicky about being transplanted and should go directly from the original containers into the garden.
If you're using a soilless mix without compost, begin to fertilize your seedlings as soon as they get their first true leaves. (These leaves emerge after the little, round cotyledon leaves.) Water with a half-strength solution of liquid fish/seaweed fertilizer every week or two. Use either a spray bottle or add the fertilizer to the water you set the trays in if you're using the wick-up method.
SPACE FOR THE SEEDLINGS
Frequently, plant quality suffers from crowding too many plants into a small area. Crowded seedlings become weak and spindly and are more susceptible to disease. Wider spacing or larger containers permit stronger growth. As a rule of thumb, to produce high quality plants, space them so that the leaves of one plant do not touch those of another.
If the seedlings outgrow their containers or crowd one another, repot them into larger containers filled with a mix that includes compost. Extract the seedlings with a narrow fork or flat stick, and handle by their leaves and roots to avoid damaging the fragile stems. Tuck the seedlings gently into the new pots, and water them to settle the roots.
TRANSPLANT THE SEEDLINGS
About 1 week before the plants are to go outside, start acclimating them to the harsh conditions of the big world. Gardeners call this hardening off. On a warm spring day move the containers to a shaded, protected place, such as a porch, for a few hours. Each day - unless the weather is horrible - gradually increase the plants exposure to sun and breeze. At the end of the week leave them out overnight; then transplant them into the garden.
If you can, transplant the seedlings to the garden on an overcast day to ease the shock of transition from pot to ground. If a light mist is falling, so much the better. Water both the outside ground and the plants before you move them into the garden.
Remove each plant from its pot by turning it upside down and tapping lightly on the bottom; it will slide out easily. Gently run your fingers through the roots to loosen them a little.
Use a trowel to dig a hole about twice the size of the rootball and set the plant into the hole so the rootball will be covered by about 1/4 inch of soil. Press the soil firmly around the roots to ensure good soil-to-root contact.
Space the plants according to the directions.
Water well immediately after transplanting and again every day until the plants are well established and growing - usually within a week. If some plants show signs of wilting, shield them with a lath screen or a piece of lattice until they perk up, which shouldn't take more than a few days.