In the spring the stores, farmer's markets and nurseries begin displaying seedlings for sale. These can be very appealing and can get your garden planted quickly. It can also get expensive to buy too many of these. Instead many people start their own plants from seeds. Besides saving money, starting your own seeds gives you a much better choice of varieties than are available as transplants. You can also save seeds from the plants you grow to keep your favorite varieties from year to year with no new seed expenses. Finally, it is very satisfying to see beautiful plants grow from tiny seeds you started yourself.
Some plants are easy to grow by planting seeds in the ground at the right time of year. This is called direct seeding. Other plants do best if they are started in a small pot and then transplanted into the garden. A few plants can be started either way. In this chart, some common vegetables are listed according to how to best start them. Comments are based on my experience growing in Portland, Oregon, Zone 8.
Direct seeding
Follow seed package or catalog directions for depth and spacing for each type of plant and the correct times and temperatures for best germination. Or ask someone you know who grows the plant. Some tips: ¨ Water area to be planted so the soil is moist. ¨ Make planting holes with your finger or a small tool and drop in 1-3 seeds. The more seeds you use the more thinning you will have to do but you will also increase the odds of growing a strong plant if you have more than one seedling to choose from. ¨ Cover seedlings and pat the dirt gently but firmly ¨ Water well, in summer you might want to add a light mulch to keep the soil from drying out. ¨ Water seedlings whenever the soil dries out. Take care to not damage delicate seedlings or roots. ¨ Depending on the plant, your seeds should sprout in 3-21 days. ¨ When seedlings are a few inches high, thin to one seedling. ¨ To avoid disturbing the roots, carefully snip off the unwanted seedlings at soil level. ¨ Keep weeds picked and protect from slugs until plants are several inches high.
Starting seeds for transplants
For some plants it's best to start the seeds inside and grow them into seedlings that you can later plant out. This can be as simple as putting a few seeds in pots on a windowsill or as complex as having an elaborate greenhouse system. Luckily it's easy to start small and then later decide how much more involved you want to get. Good places to get more information on seed starting include vegetable gardening books from the library, seed catalogs, internet searches, people at nurseries or garden centers or your neighbors and friends who garden. Follow packet instructions or check your favorite resource for the best time to start seeds indoors. Here are some basics:
Temperature:
Most seeds will germinate, or begin to grow, at temperatures of 65 - 75 degrees. This is a common household temperature but you should find a place where the temperature doesn't change a lot throughout the day and night. Some people recommend the top of the refrigerator for this purpose because the temperature doesn't vary too much.
Supplies:
Pots or containers: You can buy small pots to start seeds in or save and recycle small plastic containers such as those that salsa, dairy products, tofu, etc come in. Just drill or poke drainage holes in these recycled containers. Wash them thoroughly in hot water or in the dishwasher before use. Some people use a tiny amount of bleach (one part bleach to ten parts water) or another disinfectant to sterilize the containers. There are also pots made of peat which you can buy and plant pot and all when your seedling is big enough to go outdoors. These are best used for plants that don't like being transplanted or those with delicate roots. The easiest thing to fill your containers with is sterile seed starting mix that you can get at nurseries or garden centers. Look for sales or for larger bags that you share with someone or use for several seasons. The larger bags are a much better value than the small bags. Using these mixes prevent some problems that can discourage seed starters such as soil drying out too quickly, hard crust which keeps the seed from growing properly or fungus problems such as damping off (where the seedling dies at the soil level). Regular potting soil or fine compost might be okay for seed starting but garden soil is usually too heavy and is not suitable for starting seeds indoors. After your seedlings are growing you might want to add some fertilizer, the easiest is to use a diluted liquid fertilizer (follow package instructions for seedlings or dilute with twice as much water as they recommend). Seaweed extract is great for this kind of feeding. Another method is to carefully move the seedlings from the sterile seed starting mix once they have set of true leaves to a potting soil with fertilizers already added.
Water:
Seeds need a moist, but not wet, environment to grow in. Moisten your starting mix before planting seeds, then water from below by placing the pots in a tray or old pan and adding water to the tray, the pots will absorb the water through the bottom holes. Don't leave them sitting too long, just long enough to moisten the pot and its contents. If you water from above take care not to damage delicate seedlings and roots. Covering the pots until the seeds germinate will greatly reduce the need to water while seeds are sprouting. You can cover the pots with plastic wrap or bags or buy trays with clear plastic covers for this purpose. Check the pots every day for moisture and to see if they have sprouted. Remove the cover as soon as the seeds sprout. Once the seedlings are growing, misting them with water from a spray bottle once or twice a day helps keep them growing well. Good air circulation will also keep the plants healthy and growing strong. A small fan can be used to ensure this.
Light:
Once the seeds are growing, they need light to make food and get big and healthy. In this area it is hard to get enough light on a windowsill unless you wait until late spring when it gets sunnier for longer period s of time. If you use this method, make sure the temperature near the window doesn't drop too much over night or it might shock the seedlings. Seedlings grow best with 14-16 hours of light a day. If you have a fluorescent shop light fixture, you can use it to grow your seedlings. While there are expensive grow light bulbs, you can get good results by using one warm and one cool fluorescent light bulb in the fixture. Try to keep the seedlings within three inches of the fixture by moving it up and down as needed. Some people hang the fixtures from pulleys or chains with hooks to make this easier. The fixture will give off some heat so account for this when considering temperature. There are many other lighting systems you can buy or build, check some of the resources mentioned earlier for ideas that will fit your budget and skill level.
Thinning:
Once the seeds sprout, you will need to thin them out. The first sets of leaves that grow are the seed leaves, wait for the next set called the first true leaves before thinning. If you have started your seeds in an individual pot, snip off the smaller and weaker seedlings at soil level, leaving only the strongest and healthiest seedling. Remember tallest is not always best, a thick strong stem on a shorter seedling probably will become a better plant than a spindly tall one. If you have started your seeds in a container and need to transplant them into individual pots, carefully prick out, or remove them by gently uprooting them with a small tool or utensil. Take care not to damage the roots or stem. If you must handle them do not grab them by the stem, this can hurt the seedling. Choose the best seedlings and carefully replant them in an individual pot. Watering them before pricking out can make untangling roots easier and watering right after transplanting makes sure the roots get good contact with the new soil.
Hardening off:
Hardening off is an important step in growing your own seedlings. This is a process that gets the plants used to the outdoor weather and light. About a week or two before you want to plant the seedlings outside, begin bringing them outside. Choose a sheltered location, such as a shady or covered area. Too much rain, sun or wind at this point will shock your seedlings and delay their growth. Start with an hour a day and double the time each day until the plants are out all day. Each day give them more exposure to the actual conditions they will be growing under in the garden. If the weather turns very cold or hot or windy during this process, protect the seedlings with a covering or bring them back indoors until conditions are better.
Transplanting seedlings:
Once the seedlings are hardened off, it's time to transplant them. Have the planting area prepared and watered well before beginning. Carefully remove the seedling with its soil and plant it in a hole, firm the soil down and water well. Check your seedlings daily to make sure they are not being attacked by pests (slugs love new seedlings) or eaten by birds or other animals. Water them whenever the soil dries out until they are growing well.
Remember that seeds only purpose is to germinate and grow into plants, they just need the right temperature, moisture and light to do it and a little protection until they are strong enough to face the world alone. If you make a mistake or have problems, ask someone or use one of the resources mentioned earlier to figure out what went wrong. Then try it again because starting your own seeds is fun, interesting and saves you money. And you will enjoy your garden and it's produce all that much more knowing that you have nurtured tiny seeds into beautiful plants.