Q: I want to start some of my plants from seed inside this year. Any advice?
A: If this is truly your first effort at starting seeds, you may be surprised to learn that seed catalogs have been making their way into gardeners’ mailboxes for a couple of months already! All of the major catalogs have web sites too, however, and they can provide good information on varieties of vegetables and flowers. Local garden centers should be starting to get their 2009 seeds now, and they too are an excellent source of information on varieties to try.
For your first effort, work with vegetables and annuals since many of them are easier to start than perennial flowers. Find fun seeds to try. For the veggie garden, tomatoes, peppers, and early season broccoli are all plants that will need to be started inside. Consider interesting varieties that you can’t purchase at the supermarket. If you like annuals for your beds and containers, many are easy to start from seed.
Read the seed packet to see how early to start the seeds. Six-to-eight weeks before the average last hard frost (which is around May 15 for Colorado Springs) is the rule for most tomatoes and annuals. This means you’ll need to have your seed starting supplies ready to go no later than mid-March. You’ll need seed starting mix, containers to germinate the seeds in (two-and-a-half inch pots are usually a good choice), a way to provide warmth to the planted seeds to help them germinate, and a way to provide enough light for them once they have sprouted.
When it’s time to start the seeds, fill two-and-a-half inch pots with premoistened potting soil or seed starting mix. Write the names of the plants on markers – one for each pot. Plant two seeds at the recommended depth in each pot and cover with soil. If you premoistened the soil well, you don’t have to add any more water. Cover the pot with plastic wrap and put a rubber band around the top to hold it down if needed. Put the pots somewhere warm (on top of the water heater the refrigerator are good places). Now the exciting part – visit the seeds daily to watch for signs of life. If both seeds in each pot sprout, remove one or repot it in another pot and put the seedlings under fluorescent lights for 14-16 hours a day. (You can try a sunny windowsill, but often that won’t give the seedlings enough hours of daylight.) At least once a day, test the seedlings’ soil and give them some water if they’re dry. Brush the tops of the plants lightly to help their stems grow tougher (some people use a gentle fan to accomplish this). Once they’ve developed their second set of leaves, fertilize them once a week at half the recommended rate on the fertilizer package.
As they grow into strapping young plants, they may get too big for their pots and need to be “potted up” into slightly larger pots. This takes time, and it’s a good reason to avoid starting them too early. The earlier you start them, the more you’ll have to repot them. Raise the lights as they grow, keeping the lights about two to four inches above the top leaves.
About a week before they are to be planted outside, the seedlings must be hardened off. Place the plants outside in a shady area for a few hours, increasing the number of hours and the sun exposure each day. At the end of a week, they should be ready to be planted. On the planting day, water the plants early in the morning. Late in the afternoon or early in the evening, dig the planting holes and pop the plant out of its pot (hold it by its leaves, not its stem) and place it in the hole. Backfill the hole with some of the soil you dug out and water the plant.
Contributed by Carey Harrington, Colorado Master Gardener. For answers to your horticultural questions, contact the Master Gardener Help Desk at 636.8921 or CSUmg2@elpasoco.com
(A version of this article was published by The Gazette on 1/20/09.)