Growing Your Own: As Easy as A-B-Seed?
By: Sierra Laverty, Assistant Horticulture Director | 02/11/2019
It’s hard to ignore seeds this time of year. Many gardeners’ mailboxes are stuffed with seed catalogs, heightening our anticipation of winter’s end. Dried seed heads droop in our gardens as a remnant of the past growing season. Even winter bird feeders bring our (and our wild friends) attention to seeds.
With seeds all around us, the idea of growing our own is both thrilling and daunting. These small sprigs of life might bring us delight, until they grow tall, spindly, and ultimately collapse before our sunniest south-facing window. Why do seeds fail? What went wrong?
“Despite our best efforts, seeds started in your home often fail for two big reasons,” said Nell Lindquist, Idaho Botanical Garden’s greenhouse and nursery coordinator.
“The first is lack of adequate heat for germination. You might follow the advice of placing your seed tray on top of the fridge for warmth and maybe that will work, and you’ll get some little seedlings peeking out of the soil. Your second hurdle then is providing enough light for your seedlings to grow and thrive,” Lindquist said.
Adequate indoor light relies on four factors: the spectrum, number of lights, height above the plants and duration.
Spectrum: Plants need light that humans can’t even see (some UV and microwaves) to produce food and survive. Cool, white fluorescent bulbs provide part of that spectrum. “Grow lights” (a type of fluorescent bulb) can be more expensive, but are designed to provide the exact spectrum-range that plants need (400 to 700 nanometers).
Number: Using two “shop light” style bulbs will encourage your plants to grow more foliage and thicker, healthier stems.
Height: Indoor light needs to be adjustable. Start your seeds in a warm environment with minimal light. Once they sprout, adjust indoor lights to 2 inches above the tallest seedling. Continue to raise the lights to be 2 to 4 inches above your plants.
Duration: Let your seedlings sleep! A plug-in outlet timer will help you limit the light to 12 to 16 hours per day.
With our predominantly sunny days, Idaho is also a great state to set up a backyard greenhouse. Sound expensive? A simple, 12-foot-by-14-foot greenhouse can be constructed for around $100 using PVC pipe, a little lumber and painter’s plastic. (Check out this blog for some tips on creating your own greenhouse.)
If indoor grow lights or a greenhouse are beyond your time or budget, good news! Many plants can be seeded directly into the soil. For vegetables, try spinach, root crops (carrots, beets, radishes, etc.) and peas as early as mid-March, if the soil has thawed. Many native plants can be direct seeded now, in late winter (like Cleome or Clarkia).
The needs of plants are as diverse as they are. There are over 300,000 angiosperms (flowering plants) alone! It will take time to get to know the needs of any given plant, and how to successfully propagate them.
If the seeds come in a commercial packet, follow the instructions provided by the company. University publications and textbooks can also be rich resources, or learn hands-on with us at the Garden!