Every summer, I get a little thrill when my Bonfire begonia bursts hundreds of little lantern-like blossoms.
But I know its blaze of glory is not long for this world. The same goes for the geraniums, fuchsias and coleus, which often look their best late in the season — until they get a blast of winter’s first frosty breath.
The cold doesn’t have to spell the end for these blooming beauties. Instead of dumping them in the composter, you can save your plants — as well as your hard work and good money — by overwintering them indoors.
Here are some plant-by-plant tips on how to do it:
Geraniums (and the tender pelargoniums that we call geraniums) make suitable candidates for overwintering. They’ll do well in a sunny window in a cool room, such as a heated sun porch, where the temperatures hover between 55 and 65 degrees.
While geraniums need lots of sun, don’t place them right up against the glass, where it’s often much colder. Make sure to keep them away from cold, drafty spots as well as heat vents and radiators. When inside, geraniums don’t like to be too cold or too hot.
Once you find that just-right spot for your plants, be sure to only water when the soil is quite dry. The sturdy, fleshy stems of geraniums can tolerate dryness well. Overwatering, on the other hand, can lead to root rot.
To give these plants a boost, consider using fluorescent lights to supplement the sun during the shortest days of the year. Setting the timer for four hours (generally from 6 to 10 p.m.) should make your geraniums happy during their stay indoors.
Fuchsias do fine indoors — if you lower your expectations on their looks. These plants are very sensitive to changes in light levels, including intensity and day length. So don’t count on them to bloom past October.
After bringing them in, gradually cut back on watering them until they enter a semi-dormant state, in which you only water occasionally. They do best with indoor temps of 45 to 55 degrees.
Of all the begonias, I find the angel wing and dragon wing type the easiest to overwinter. Because they have a fibrous root system, you can grow the entire plant indoors rather than storing the tubers, as with other begonias.
Plus, with enough bright light, they’ll maintain some of their dignity, although they won’t look their summer best. Keep them slightly moist throughout the winter and feed them with a fertilizer mixed at a quarter of the regular strength every now and then.
These showy foliage plants tend to look teasingly spectacular at the end of the growing season. But don’t be fooled into trying to overwinter whole plants. Instead, I recommend that you take cuttings.
While the plant is still vigorous, use a clean scissors to cut off a few growing tips. It may be tempting to stick them in jars of water so you can watch the roots appear, but the cuttings will be healthier if you root them in soil from the beginning. You may also want to use a rooting fertilizer to speed the growing process along.
In March, begin to pinch back any weak stems on your overwintered plants to spur on new growth as the days lengthen. You can start to water and fertilize more regularly as the air begins to warm outside.
When all danger of frost is past and nighttime temperatures have stabilized, bring these plants outside for a little while every day to harden them off. That should give them a head start on yet another growing season.
Rhonda Hayes is a Minneapolis-based garden writer. She blogs at www.thegardenbuzz.com.