Growing your own transplants is not hard nor does it have to be complicated. But there are a few points that you need to remember to be successful.
Choosing the right seed
One of the many advantages of ordering your seed from a seed catalog is the opportunity to choose different and unique varieties. From the many mail-order (online for you internet geeks) seed companies, you can choose many different varieties heirloom, organic, unusual, rare, or just plain hard to find selections. One of my favorite finds has been the Naga Bhut Jolokia pepper, but that is another story. When I browse and make my annual seed selections, I often choose what sounds fun and has a potential in my kitchen. Make sure that you pay attention to the days to harvest, plant size and other environmental needs, but I typically am willing to try just about anything. Don't be afraid to experiment.
Now that you have your treasures, it is time to think about starting your transplants. Here is where you can show off your gardening skills, even if you don't have any. The key factor here is cleanliness. Here are some of my dos and don'ts:
Use only clean fresh germinating mix. When choosing your germination substrate you always get what you pay for. Buy the good stuff. Make sure that it is mostly sphagnum peat moss with vermiculite or perlite.
Do not use garden soil or leftover potting soil from another project. These are likely contaminated with damping off diseases. Yes I know you can cook it in the oven, but save your oven for cookies. I also only buy small bags. It is easier to keep your germinating mix clean by keeping it closed.
Use clean containers. I like to use the clam shell containers that fresh berries are packaged. They are clean, have drainage, and are instant miniature greenhouses. Ideal for the intense recyclers in the house. To wet the germinating mix, I prefer to add water from the bottom up. I use a mortar mixing tub, but you can use anything that you like, just keep it clean. Uniform moisture is crucial for successful germination. You can keep your germination mix moist with a mist bottle (rinse out the window cleaner please) until your seeds have sprouted and have started to form leaves.
Avoid old and dirty flats. You can re-use flats from earlier seasons, but make sure that they are scrubbed and sanitized. You can mix some regular household bleach with water (1:10) for a nice disinfectant. Make sure that your containers have good drainage.
Choose a warm space for your seed near a sunny window. Most seed needs to be sown and started four to eight weeks before your transplant date. Choose a sunny spot. Bright light is crucial to many cultivars. Read the instructions on the seed pack.
Starting too soon can result in tall and weak seedlings. If you are energetic and willing to make a small investment, artificial light may be in order for you. A simple shop light with fluorescent bulbs is more than sufficient for many applications. However, if you plan to grow your own transplants for many seasons, don't be afraid to invest in a quality grow lamp. You can find these at most independent garden centers or specialty grow shops.
Transplant your seedlings on schedule. Overgrown seedlings are a pain to transplant and separate. Your seedlings will grow faster and be stronger with proper transplanting. Make sure your seedling mix is moistened before you transplant.
When the last danger of frost is present, starting to harden off your transplants by gradually exposing them to out doors. Make sure that you don't allow them to wilt, but they will harden off more quickly if you allow them to dry a bit with reduced watering. I am always anxious for spring and often put my plants out too early. Some times I get an early harvest, but sometimes I lose. If you grow your own transplants, you can move a portion out and save some in reserve.
For more information on growing your own plants from seed, please see our Fact Sheet at:
Steven E. Newman, Ph.D., A.A.F.
Greenhouse Crops Extension Specialist and
Professor of Floriculture
Floriculture and Greenhouse Crops Extension