Growing Green: Successful Seed Starting
Now that winter is upon us, I love to sit snuggled in a cozy chair with my seed catalogs and pick out the plants I will include in my garden in the spring. If you start your own seeds, you will have a much greater selection of vegetables, flowers and herbs varieties than you will find available locally. The choosey gardener can select unusual cultivars, and seeds that are hybrid, heirloom, open pollinated, organic... the options are just about endless (and can be overwhelming!) We start just about all of our plants from seed each year (about 15,000 plants) and have had many great successes and several utter failures. The trick to successful seed starting is to begin with the right equipment and raw materials. Here are a few items to have on hand when starting your own seeds:
Seeds: Try to purchase fresh, high quality seeds each year. Germination rates can be affected by improperly stored seed. Try to purchase seeds from a company that lists its germination rates. If you have saved seeds you would like to plant, check your germination by placing a few seeds wrapped in a moist paper towel and placed in a Ziploc bag. Usually in 5-14 days (depending on the seed variety) your seeds should begin to sprout. If not, toss them and start with fresh.
Containers: Many things can work as seed starting containers: egg shells, egg cartons, yogurt cups, used cell paks...the important factors in selecting containers is that they have drainage, and they are sterile. Clean used containers with a bleach solution and let them air dry. Clean, sterile containers won't spread disease.
Soil: Fine, sterile soil is important to prevent damping off and other deadly diseases which can stop your seedlings before they ever get started. Commercial, peat based seed starting mixes are readily available; however, these do not contain lasting nutrients for healthy plant growth. After about a month, you will have to apply fertilizer to your seedlings.
Light: Some seeds require light for germination, others require darkness. Check your seed packet's recommendations. We start all of our seeds under 4' shop lights containing two 40 watt bulbs. (Old bulbs can decay over time, producing lower, uneven light. We try to replace bulbs that are more than a few years old to assure our plants are receiving proper light.) The trick to healthy plant growth is to keep these lights close to your seeds/seedlings (no more than 2-4" above growing plants.) Shop lights are generally suspended by chains, so moving them up is just a matter of shortening the chain.
Temperature: This is the area in which we have the most trouble. Many plants require very specific, consistent temperature in order to germinate and grow. If they don't receive the correct temperature at the proper time, they won't germinate at all, or if they do, their growth will be slow. (Lisianthus, garden phlox, and eryngium have been our greatest challenges!) We hope to have solved this problem with the purchase of a heat mat. Flats are set on the mat, and the temperature control will keep the flats at an even, appropriate temperature for germination and growth.
Fertilization: Start feeding your seedlings when the first true leaves appear,. We use compost tea, but any balanced all-purpose fertilizer will provide the necessary nutrients. Apply half the recommended concentration every 10-14 days until you transplant into the garden.
Timing: So, you've accumulated all this stuff. How do you know when to start your seeds? Our average spring frost free date is May 15, so that's about the earliest you can put transplants in the ground. Check out the instructions on your seed packet, usually it will tell you how many weeks ahead to start your seeds indoors, and when to transplant them. Johnny's Select Seed has a great seed starting calculator and other interactive tools that are helpful for the home gardener. http://www.johnnyseeds.com/t-InteractiveTools.aspx. For more information about seed starting, visit http://www.extension.umn.edu/distribution/horticulture/M1245.html. Good luck with all your seeding adventures!
Until next time, joyous New Year and happy gardening!
Robin Trott is a Horticulture Educator with University of Minnesota Extension.