Starting vegetables, flowers and herbs from seed is a rite of spring that is satisfying and undemanding. This time of year, vegetable and bedding plant producers from the Belfast Farmers' Market are busily planting and caring for the seedlings which will produce this season's harvest. Growing from seed is a skill well worth learning for any gardener, since it allows a much wider choice of varieties than is available from any garden supplier.
Seeds should be started in a sterile soil mix which is low in nutrients and light in texture, such as Pro-Mix ( a medium composed of peat moss, perlite, and vermiculite). Potting soils are generally too heavy and don't allow for air circulation to the plant's roots. Wet the soil and mix it thoroughly before putting it in containers. We produce so many seedlings that we find it convenient to use commercial plug flats, but for small-scale growing any container with drainage holes will do. Recycled six-pack plant containers, small pots, plastic margarine buckets with holes poked in the bottom, or other household containers can be recruited to serve as plant containers. However, if containers that have held other plants are re-used, they should be thoroughly cleaned and sanitized with a weak bleach solution first.
Small seeds can be started in community flats, but be careful not to plant too many seeds per container, or the seedlings will crowd each other. As a general rule, seeds should be planted to a depth equal to three times its thickness. Some flower and herb seeds have special needs, such as darkness or cold treatment to germinate. Seed to Bloom, by Eileen Powell, is an excellent reference for this kind of information. Most flower and vegetable seeds require warmth (65-85 degrees) and light to germinate. Keep them uniformly moist, but not wet. Bottom watering is a good method for this; so is frequent spray misting. As soon as the first sprouts appear, place the containers under strong light, such as a sunny windowsill or florescent grow lights. Young sprouts can be watered with a spray mister. As the plants develop, water them whenever the soil surface becomes dry. Do not overwater, since it encourages fungal diseases like damping-off.
Some vegetables, such as tomatoes, peppers and eggplant, can be sprouted before planting. This is a good idea, since it avoids the problems of overplanting and planting too deep.
To presprout, label a napkin with the variety name and moisten it carefully. Place a few seeds in the napkin, roll it up and put it in a plastic bag such as a freezer bag. Put the bag in a warm place out of direct light (we use the top of the refrigerator) and leave them there for a few days to 2 weeks. It's important to check the seeds every day, since they won't all germinate at once. A small white shoot will appear, followed by the tiny seed leaves. Transplant the sprout to a container of starting medium, allowing the leaves to project above the soil.
It's a good idea to transplant seedlings to a larger pot early in their development, when the first true' leaves appear. These may be very different looking than the seed leaves. As a general rule, seedlings should be transplanted if their leaves can touch their neighbor's leaves. Also, a richer soil mix can be used when the seedlings are potted up. Carefully prick out the seedlings, breaking off as few roots as possible. Tomato seedlings should be transplanted fairly deeply (up to the seed leaves) to promote root growth. Select the strongest looking, best developed seedlings for transplanting. Keep newly transplanted seedlings out of direct sunlight for a few hours to let them recover and avoid transplant shock'.
After seedlings develop their second set of true leaves, feed them weekly with a dilute spray of fish emulsion or seaweed emulsion. We use about 1 tablespoon per 2 quarts of water.
Seedlings that are not given enough light may become leggy', or tall and thin. This isn't good plant form, since such plants may break or fall over when transplanted outside. One method for avoiding this is to place a small fan near the seedlings, set so that their leaves move slightly in the breeze. This will encourage them to form thicker stems and branches. If seedlings are grown on a windowsill, rotate the pots every day or so to discourage uneven growth.
A few weeks before you plan to plant out your seedlings, begin the process of hardening off.' This process toughens up the plants so that they can survive the stronger light, wind and temperature range of the outside world. Stop feeding them and water less frequently. During the final week before transplanting, leave the plants outside in a sheltered place for an increasing number of hours per day. After they have spent a night outside, they're ready to transplant to the garden. A cold frame makes the process of hardening off much easier. Just set the plants out in it, and raise the glass lid for a longer time each day.
When using a cold frame, it is important not to allow the plants to overheat. This can happen quickly on a bright day, even if it isn't hot out. Automatic vent openers, costing about forty dollars, can save even more costly cooked seedlings. The opposite problem is too much cold at night. Covering your cold frames with blankets will keep even sensitive tomato plants safe down into the twenties.
On planting day, move the seedlings out to the garden and mix up a batch of transplant solution. We use about « gallon of compost tea to 5 gallons of water. Dig the holes at the recommended depth and spacing for each variety. Pour the transplant solution into the hole. Remove the plant from its container, being careful not to disturb the root ball, and plant in the hole. Gently firm the soil around the roots. Keep the plants well watered until they become established. Vegetables such as peppers, tomatoes and eggplants benefit from a bit of protection from the wind after transplanting; row cover such as Remay suspended on hoops is ideal.
The Belfast Farmers' Market will be closed for the month of April. We will open again at our site in Reny's Plaza on Friday, May 7. After that we will be open Tuesdays, 2:30-5:30, Fridays and Saturdays 9:00-1:00. Seedlings and bedding plants will be available at the market through the growing season.