Even though we didn't have a hot summer, the coleus has looked hot, hot, hot. The brilliant, variegated leaves of these plants, which are grown here as annuals, tend to steal the spotlight in early fall, when other plants have lost their luster. But as tropicals, they can't take the cold. Instead of letting your coleus go with the first frost, try overwintering them by taking cuttings.
"If you've got a sunny window, anyone can do it," said Steve Kelley of Kelley & Kelley, the Long Lake nursery known for its coleus.
Kelley doesn't recommend overwintering entire potted coleus. He said he's had limited success with that, even in a greenhouse. Instead, he recommends taking cuttings from your favorite plants.
But don't wait too long. Coleus, whether in a pot or in the ground, is "very tender. It'll go at the first frost, just like basil," he said.
TO OVERWINTER COLEUS
Follow the directions below, by Pam Baggett, author of "Tropicalismo!" (Timber Press, $14.95), a soon-to-be-released book on using tropicals in your garden.
1. Several weeks before a hard frost, take 4-inch-long cuttings from the tips of your favorite coleus. Strip the leaves from the bottom 2 inches of each cutting. Stick the bare portion of each stem into a small pot of sterilized potting soil. Make sure you have at least one leaf node buried in the soil.
Keep the potting mix damp but not soggy and place the cuttings in bright light but out of direct sun. Within four weeks, you should have well-rooted plants.
(Coleus cuttings can root in a glass of water, but the roots will be fragile and easily injured when you pot up your plants.)
2. Once your cuttings are well-rooted, move them into larger pots, which hold two to three cups of soil. Move them to the sunniest window of your house or place them under artificial lights. Make sure the plants remain at temperatures above 60 degrees for the entire winter.
3. Once your plants are settled, add a half-strength dose of time-release fertilizer to the soil surface of each pot. To produce stronger, bushier plants, pinch the growing points out of each tip.
4. Keep the plants fairly dry to avoid rotting their roots. Water only when the soil surface is completely dry.
5. The low light levels of mid to late winter are tough on coleus. They long for the tropics, where the sun shines 12 hours a day. If your plants lean toward the sun on weak, spindly stems, consider investing in inexpensive grow lights.
Coleus sometimes lose their brilliant colors in winter, but they will recover them in summer when they're exposed to full sun.
6. When winter is over, acclimate your plants to the outdoors in stages. Take your coleus outside and place them in light shade when temperatures are above 60 degrees. Bring them back in at night. Gradually ease the plants into more sun and start giving them more water.
7. Once nighttime temperatures are certain to stay above 50 degrees, you can plant your coleus outside. Don't rush to plant sooner. You'll only risk damage to their tender leaves. As the weather warms, they'll grow like crazy -- and you can boast that you grew them yourself!