Now that your seed orders are beginning to arrive, you are probably wondering first, why did I order so many seeds, and secondly, how to get the seeds started in order to have respectable sized transplants come spring. I start quite a number of plants from seeds including peppers, tomatoes and leeks plus a selection of flowering annuals. It is really the most economical way to obtain a large number of plants plus many interesting species and cultivars that cannot be purchased locally.
Equipment needed to achieve successful seed germination and plant development includes a light source, seed starting medium, fresh seeds and growing containers. Although seeds can often be grown on a bright windowsill, a fluorescent lighting fixture equipped with full spectrum or grow lights will give you the best results. If at all possible set up lights so they can be raised as the seedlings grow. You do not need expensive light stands. A shop light fixture suspended over a table or lights installed in a repurposed bookshelf can do.
Although one can make their own starting medium, commercial seed starting mixes are more convenient for most folks and quite suited to the task. They hold water well and are fairly sterile which helps prevent damping off, a fatal seedling disease. Some commercial mixes also contain fertilizer. Be sure to check if yours does and modify your feeding schedule accordingly.
Almost any kind of container will do as long as it is free draining and not too deep. Some prefer to start seedlings in individual cell packs, pots or cups and this is recommended for those difficult to transplant crops like melons, squash, poppies, lupines and such. My personal preference is to start tiny seeds as well as those that are easily moved in flats and then transplant the seedlings after the first true leaves appear.
Usually it says on the package how many weeks before setting out to start the seed. Tender plants such as tomatoes and zinnias are traditionally set out around Memorial Day weekend. The average last frost date for Connecticut is around the middle of May but it does vary yearly as well as by location so check the weather forecast before planting tender annuals outdoors. To find out the average last as well as frost date in your town, check out http://www.plantmaps.com/interactive-connecticut-last-frost-date-map.php
Cole crops and hardy annuals can be set out earlier, generally in late April or early May depending on the weather conditions. Count back the number of weeks before setting out and if you are growing many different types of seeds, you may want to mark their starting dates on calendar to ensure all are started on time.
Moisten the seed starting mix with warm water until thoroughly moist but not saturated. Fill the containers almost to the top packing gently. Filling the containers only halfway impedes air flow and may lead to damping off. Some seeds, such as petunias, need light to germinate while others, like phlox, require total darkness. Check the seed packet for this information.
Larger seeds including tomatoes, marigolds and zinnias can be covered lightly with the seed starting mix. Small seeds should just be sprinkled on the top of a container filled with mix and lightly patted in. After seeding, I will mist lightly to gently settle the seeds and planting mix. Cover the containers with clear plastic domes or bags to keep the moisture in. Make a few holes in the bags. Place the containers in a warm spot (65 – 70 degrees F) under your light source but not in direct sun. Containers with seeds that require total darkness can be covered with black plastic. Do not forget to put labels in each container with the plant’s name and the date the seed was planted.
Check your containers frequently for germination and moisture. The medium should be kept damp at all times. Some seeds germinate in a few days and others, especially some perennials, may take several weeks or longer. Also some plants prefer to be moved to cooler temperatures after germinating.
If using plant lights, position them about 2 inches above the plants when germinating and raise as the seedlings grow to a maximum of 6 to 8 inches about your plants. Transplant seedlings if necessary when the first true leaves appear. Use a pencil or chopstick to lift and dislodge the roots. Grasp seedlings gently by a leaf and move the young plant into individual pots or cells when using packs. Water after transplanting.
Start to fertilize the plants as soon as the first true leaves appear. Use a water soluble fertilizer that also includes micronutrients but make it at half strength. Fertilize once a week and be sure to water in between fertilizer applications.
As the weather starts to warm, harden off transplants before setting them into the garden. Do this by gradually exposing them to more hours of sunlight each day. Yes, this does involve a bit of planning and moving them in and out but the plants will be ready to withstand the rigors of garden life much more quickly and, healthy plants make for a bountiful harvest.
For questions about seed starting or any other gardening questions, contact the UConn Home & Garden Education Center, toll-free, at (877) 486-6271, visit www.ladybug.uconn.edu or call your local Cooperative Extension office.
Dawn Pettinelli works at the UConn Home & Garden Education Center