Now is the time to sow & grow your seeds.
Choose potting soil that’s made for growing seedlings. Do not use soil from your garden or re-use potting soil from your houseplants. Start with a fresh, sterile mix that will ensure healthy, disease-free seedlings. Before filling your containers, use a bucket or tub to moisten the planting mix.
Special requirements for certain seeds
It is very important that you make sure that the seeds you plan to grow don’t have any special pre-sowing requirements before. Some seeds won’t germinate unless they are sown while fresh, or will only sprout in the dark or in the light. Other seeds may require soaking in room temperature water for a few hours.. or days. Seeds that require ‘stratification‘ must be placed in a moistened rooting medium and kept in the freezer for a designated length of time.
Some seeds have hard seed hulls and may require scarification.
Scarification involves scratching or nicking of a seed’s shell to facilitate germination.
It is a good idea to do your sowing in stages so that in the event of a disaster you have a second chance.
Depending on the size of the seed you may have to create a seed ‘trench’ or punch a row of small holes with a dibble stick. The rows should be at least an inch apart. Planting depth is critical. A rough rule of thumb is that the planting depth is one or two times the diameter of the seed. Most very fine seeds should not be covered at all, nor should seeds that require light for germination. Pelleted seeds should not be covered. Merely press them into the surface of the soil mix.
You are now ready to sow your seeds
This greenhouse environment will almost eliminate the necessity of watering the bed again before the seeds germinate. Be sure to keep an eye on it though, Never let the soil mix dry out completely! Place your flat in a warm area where it will get good light but not direct sun. Germination can take anywhere from a few days to several months, depending on what you are growing, so patience will have to be on of your virtues. Once the seeds have poked their little heads up, remove the greenhousing and gradually move the flat into brighter light or full sun. Your seedlings will be quite tender and fragile at this time, and a radical lighting or temperature change can be disastrous.
The critical seedling stage
Carefully distribute your seeds onto the medium or into the small holes, using care to be sure that they are not crowded. This will ensure room for growth as well as good light and air circulation to the seedlings as they develop. It will also make it easier to transplant the new plants when the time has come. Now you should create a miniature greenhouse environment for the pots or flats – see what propagators we have in store.
At this stage, the seedlings have underdeveloped root systems, so watering is critical so check on them daily. The potting medium must remain moist, but never wet or soggy, because this will prevent oxygen to the roots and drown your new plants. Bottom watering is always best at this point because spraying can dislodge the plants and water on the leaves may lead to fungus attack. Temperatures should be kept at about 70°-75° (higher for some plants).
Once the first true leaves (the second set of leaves to emerge) develop, you can begin to lightly feed your plants. Up until this time the seedlings have been being nourished from the seed itself. Fertilising should be still done from the bottom at this point,
using a very diluted ¼ strength mix of an all purpose plant food once a week.
When the plants have reached about 3 inches you can begin to water and feed the plants from above. When the plants have developed 4 true leaves, it is time to thin and transplant them into pots. Seedlings growing in a tray should be thinned to one inch or more apart,
where they may remain until they are ready to be planted in their permanent home.
Always water plants thoroughly prior to any thinning, repotting or transplanting.
Use the handle of a spoon as your shovel to remove the seedlings from the pot or flat, and very gently separate them, being careful to do as little damage to the roots as possible.
Always handle a seedling by the leaves and NEVER by the stem.
Even slight pressure can permanently damage the stem, whereas the plant will grow another leaf if it is damaged.
Move the plant to the new pot, gently dropping the roots into a pencil size hole which you have ready. Set the seedling so that it is a tiny bit deeper than the level it was previously growing at. Gently press the medium around the roots. It is normal for a certain amount of wilting to occur after transplanting, due to some root damage and general plant shock but he plants should recover quickly. Keep the plants in good light for several days but not full sun. Gradually increase the light intensity. If the plants begin to get tall and spindly, they are not getting enough light and should be moved to a brighter spot. Water when necessary to prevent wilting. The medium should be kept moist but never wet or soggy.
Light feeding can be done weekly at ½ the fertilizer’s recommended strength.
Hardening Off and Planting the Seedlings
The final step is hardening off or acclimatizing the plants to the outdoor world.
During this process, make certain that the plants are kept well watered.
Move your trays or pots of plants outdoors to a shaded, sheltered area.
When the temperature begins to drop at night, bring them back indoors.
After doing this for 2-3 days put them into an area where they will receive a half day of sun.
Bring them in at night if it is expected to get cold.
Two to three days later let them have full sun (if they are sun lover plants).
After this hardening period your new plants are ready to move into their permanent position in the garden.
Take precautions if slugs and snails are a problem in your area,
because a slug with an attitude can virtually eliminate all of your hard work in a matter of hours.