This is the time of the year when gardeners are pouring over seed catalogs dreaming of what seeds to plant when spring finally arrives. Those little seeds are truly God’s wonders. They contain all that is necessary to produce a new plant. Did you know that orchid seeds are so tiny it takes 800,000 of them to make an ounce? But coconut seeds can weigh as much as 50 pounds! And, amazingly, the size of the seed has nothing to do with the size of the plant it produces, as the acorn growing into the oak shows us.
You don’t have to wait until May to get your hands in the dirt and start planting your seeds. You can have fun this winter starting your own vegetables and flowers from seed and watching them grow. Of course, you could buy your bedding plants from a nursery in the spring. But it’s more fun and cheaper to grow your own.
Many vegetables, flowers, and herbs need to be started from seed early in order to mature. And remember, even though you are starting peppers and tomatoes inside, you still need to pick early-ripening varieties for our short growing season. Broccoli, cauliflower, cucumbers, pumpkins, and winter squash are other vegetables started early inside. Herbs, such as basil, oregano, catnip, thyme, and rosemary, are easy to grow from seed. When you want masses of a perennial flower, it can be a money saver to start your own seedlings. Columbine, lupine, hollyhocks, gaillardia, shasta daisy, and purple coneflower are a few popular perennials that grow easily from seed.
Plant your seeds in plastic flats or pots made for that purpose or you can cut down paper or plastic milk cartons, aluminum cans, or other containers you have at home. At the nursery we seed into flats and then transplant into plastic or peat pots. Convenient peat pots can be planted, pot and all, directly into the ground when it’s time. Whatever you use should have drainage and be clean. Used pots with traces of soil in them can harbor diseases. So wash out whatever containers you use with a weak solution of one part bleach to nine parts water.
Of course, you will need soil in which to plant your seeds. Real topsoil is not recommended unless it is sterilized, because it can cause seedlings to ‘dampen off’. Damping off is a soil-borne fungus disease in which the seedlings wither and die at ground level. A fine seed-starting mix with a blend of sphagnum peat moss, vermiculite, and other sterilized components works best.
The date you start your seeds depends on germination time, growth rate of the plant, and when you dare to plant outside. Depending on the variety, it could take anywhere from 6 weeks to 3 months to start perennial seeds inside. April 15 is a good starting date for frost tender basil, pumpkins, winter squash and cucumbers. Seed broccoli, cauliflower, and brussel sprouts 6 to 8 weeks before you want to plant them outside.
Large seeds, such as pumpkins and cucumbers, can be planted directly into peat pots or other containers you are using. We plant small seeds like tomatoes densely in rows in seeding flats and transplant them when they are about 2 inches tall. But if you are doing this on a small scale, planting one or two tomato seeds directly into your peat pots will work. The depth most seeds are planted should equal the length of the seed. Do not plant them too deep. Seeds need the proper moisture and temperature to germinate. Moisten the soil medium before you plant; and then keep it evenly moist but not soaking. If possible, use a clear dome or some other device to keep the humidity up. Although some seeds need higher or lower temperatures, 70 degrees soil temperature is best for germination.
Nancy Berg, our bedding plant grower, worries that a common mistake people make is keeping their flats of seeds on a windowsill. The flat gets warm in the daytime, but at night, especially near a cool window, will be too cold for germination to occur. We use germination mats which heat the bottom of the flats to an even temperature.
Some seeds need stratification and scarifying in order to germinate. Stratification means to supply a period of moist cold to trick the seeds into thinking they’re experiencing winter. Columbine and purple coneflower are two popular perennials seeds that you will need to stratify for at least 3 weeks. Scarifying means to nick the hard outer seed coat with a knife or sandpaper so moisture can reach the inside of the seed for germination. Lupine seeds need to be scarified. Soaking the seed before planting also helps to loosen the hard seed coats.
Most seeds germinate in 5 to 14 days. Once your seedlings are up, remove them from the heat mat and remove the grow domes. Most seedlings grow best at around 70 degrees. They may get too hot in direct sun and stretch toward the light. Grow lights work well, but a bright room out of direct sunlight will work fine, too. It is important to keep the soil evenly moist but not too wet. A good misting in the morning is probably enough.
When your seedlings have developed their first set of true leaves, they are ready for transplanting into individual pots. Plant a clump of herb seedlings in each pot for best results. For tomatoes and peppers, plant just one per pot. Fertilize your seedlings about once a week with a water soluble fertilizer. Miracle Gro (15-30-15) fertilizer used at the houseplant rate works well.
Grow your own bedding plants so you and your family can marvel at the wonder of seeds. Then, in May, you will be ready to plant your seedlings outside. And enjoy your garden!