Question: I’m intrigued by the many varieties of basil—cinnamon, lemon, lettuce-leaf, purple, Thai, etc.—but our local garden center sells transplants of only common basil. When I asked them about other kinds, they said I’d have to grow the plants myself from seeds. I’ve never done that before. Can you give me some tips?
Answer: Raising seedlings takes a little planning and patience, but it isn’t difficult and the results are very gratifying. Most of the seed and herb companies that advertise in The Herb Companion sell basil seeds. Study the catalogs and place your order early. Just one packet of each variety you choose will contain far more seeds than you need for a single growing season, so save the extras for future use by refrigerating seed packets in a plastic or glass container with a tight-fitting lid.
Although basil may be sown directly in the garden, sowing outdoors requires close attention and good luck. Sowing indoors is safer because you can protect the plants and provide ideal conditions. Here’s a simple method that works well for growing small quantities of several varieties.
• Timing. Ask local gardeners when it’s safe to plant basil, tomatoes, or other heat-loving crops outdoors. Count backwards about eight weeks from that date to determine when to sow basil seeds indoors.
• Indoor setup. A windowsill isn’t an ideal place to grow seedlings because it tends to be too hot on sunny days, too cold at night, and too dark on cloudy days. Instead, grow your seedlings under artificial light. An inexpensive shop-light fixture with two ordinary 40-watt, 48-inch fluorescent bulbs will illuminate six to eight dozen seedlings in small pots.
Choose a room where air temperatures range in the 70s by day and high 60s at night. Hang the light fixture from the ceiling or support it on blocks so that the bulbs are about 12 inches above the surface where you will set the pots of seedlings. Plug the lights into a timer so they will turn on automatically at about 7 a. m. and off at 11 p. m.
• Pots. Use new or recycled 2-inch nursery pots, or convert empty yogurt cups or styrofoam drinking cups into seedling pots by poking holes in the bottoms and trimming down the tops. You’ll grow one plant per pot, so collect or make as many pots as you need. Setting the pots in a waterproof tray or baking dish makes it easier to carry them around and contains spills and drips.
• Soil. Garden soil is not suitable for starting seeds indoors. Buy a bag of special “seed-starting” soil mix at any garden center or discount store. To use it, add a little warm water and stir gently until it seems moist. Wait an hour or so for the water to soak in, and add more if the soil seems dry. Then fill the containers to within about half an inch of their rims.
• Labels. Buy or make some little plastic or wooden labels, use a pencil or waterproof marker, and label each pot as you sow the seeds.
• Sowing the seeds. Place three or four seeds on top of the soil, spaced a bit apart from each other. Press them gently against the surface and cover them with just a pinch of additional soil. Set the tray of pots under the lights so the top of the pots is three or four inches below the tubes. Check the pots every morning to see if the soil is moist or dry and sprinkle gently with tepid water if needed.
• Tending the seedlings. In a warm room, the first sprouts will appear in about one week and the seedlings will grow quickly over the next month or so. As soon as you can make up your mind, choose the strongest-looking seedling in each pot and clip off the others with scissors. As the seedlings grow, lower the tray to keep the top leaves about three or four inches away from the fluorescent tubes. Once a week, fertilize the seedlings with a water-soluble houseplant fertilizer prepared at one-quarter the strength recommended on the label.
• Hardening-off. Prepare the seedlings for the garden by exposing them gradually to outdoor conditions. Set the pots under a tree or on the north or east side of the house for a few days, then move them to a sunny, open location for a few more days. Be sure not to let the seedlings dry out, and bring them indoors if temperatures threaten to drop below 60°F. After a week or so, if you’re sure the weather is going to stay warm, transplant the basils into the ground.
• Other seeds to try. While you’re at it, you could grow some tomatoes and peppers along with your basil. The seedlings require similar timing, care, and growing conditions.
Rita Buchanan grows many herbs in her garden in Winsted, Connecticut.