My friends Lynn and Ralph have a showcase garden, carefully tended as a labor of love. Countless varieties of magnificent bulbs, perennials, and annuals from specialty nurseries fill the beds of their charming hillside residence from early spring to fall. But this garden-happy couple takes great pleasure in propagating many of their plants from seed as well. Ralph thinks nothing of spending hours planting hundreds of tender zinnia or Mexican sunflower starts and scattering multihued columbine seeds from flowers harvested in previous years. If sweet pea seeds are in the ground by mid-March, sherbet-colored bundles of the heirloom flowers fill their home in early summer, and a later brilliantly hued zinnia crop is spectacular.  That’s to say nothing of the vegetables and herbs—oh, my! Dinner at their home always includes something special, like salads composed of delicate baby lettuces and tiny pink French radishes, slender haricot verts, or rainbow-hued Swiss chard, not to mention baby cucumbers and pungent basil on just-picked tomatoes that taste like the summers of my childhood. Once, years ago, there was squash grown from seeds harvested on a trip to Italy, where they encountered a farmer with unusual varieties and dried the seeds in the Tuscan sun on the back window ledge of their rental car. Since then, international agriculture rules have changed, so there’s no more bringing seeds back in their suitcases. But there are suppliers who handle seeds from other continents as an alternative.  As dramatic as the rewards are for gardening with seeds, the process is somewhat simple, Ralph told me when we were talking about his bumper crop of Mexican sunflowers the other day. He got me to thinking that I was missing a great gardening opportunity.  So how do you begin? If you don’t have a greenhouse—and most people, including Ralph, don’t—a simple cold frame—a transparent-roofed enclosure built low to the ground—can be used to protect young seedlings from early-spring cold weather.

Think of it as a mini-greenhouse that creates a microclimate, providing several degrees of air and soil temperature insulation to extend your growing season by a month or more.  Although kits and commercial systems are available, you can easily build your own with an old glass window. Build a wood frame a foot or two high and place the window on top, sloped toward the winter sun to catch more rays of light and help with runoff of water. Put the window on hinges so it’s easily accessible, and make the front of the frame removable to provide air circulation before it’s warm enough to remove the top. If you don’t have a window, use rigid or clear plastic sheeting instead. An electric heating cable can be buried in the soil. To easily rotate your crops of seeds in and out of the cold frame, consider, as Ralph has done, recycling wooden wine boxes filled with potting soil and tidy rows of seedlings.  Once the seedlings begin to grow, they should be exposed to bright light for at least eight hours a day. Check moisture daily but don’t overwater, and every five days or so, feed with liquid nutrients to develop a strong root system to help once the plants are large enough to be transplanted into the garden. Sometimes, there will be an intermediary step, from the cold frame into four-inch plastic or peat pots. When sowing hard seeds like beans or sweet peas, soak overnight to soften them and assist with earlier germination.  When your garden is in full swing, enjoy the seasonal bounty and begin to plan for the following year’s planting. Most vegetable and flower seeds will be productive for three to five years. Harvest your seeds on a dry day, and if at all possible, keep them in the original seed packet so that you retain the planting and care instructions. Otherwise use a sterile glass jar stored in a cool, dry place or in your freezer. Chances are you’ll end up with more seeds than you’ll actually be able to use. Great gardens come from sharing, and this is the perfect opportunity to be generous. Maybe next year, Ralph will send some of those Mexican sunflowers over to me.