FEELING READY FOR a garden experiment? Overwintering your favorite (tender) plants is completely doable, provided you can furnish the proper conditions. Think light and airy, or cool and dark. Either way, you’ll need to maintain frost-free conditions.
Mine is a low-touch (lazy?) approach. Many plants, like Fancy Leaf pelargoniums, scented geraniums, and numerous cactus and succulents, will survive outdoors if kept under cover so that their roots can go almost completely dry. A covered patio or porch, an unheated greenhouse, or even deep overhanging eaves will keep plants sheltered from rain while still providing access to light and good air circulation. Because plants are still growing, albeit very slowly, give them an occasional sip of water — say, once a month.
If a hard freeze or a dreaded Arctic blast is forecast, I hustle my semi-protected plants into our unheated garage until the worst of the weather has passed. On a good year, my plants never even drop their leaves. They might not win any botanical beauty contests, but they survive to flourish in the next growing season.
Gardeners looking to overwinter less hardy plants (or those that represent greater financial or emotional investment) will need to identify indoor areas that will provide safe harbor. Cool, dark conditions, like those found in an unheated basement, a garage or a shed, will lull your lovelies into dormancy and hold them there in relative suspended animation.
Liane Smith, a plant buyer at Swansons Nursery, offers the following tips for gardeners looking to overwinter fuchsia baskets. “Cut plants back by at least one-third, and, ideally, bring them indoors before the first frost,” Smith says. “Keeping [the plants] somewhere cool and dry, but not freezing, is ideal.” Don’t be alarmed when your fuchsia drops all its leaves.
A similar overwintering approach will work for angel’s trumpet; banana; and other tender perennials, like elephant ears. However, allow these plants to go dormant and drop their foliage without cutting them back.
Without leaves, dormant plants require minimal upkeep. Nursery pros recommend moistening roots with a light watering on major holidays, or about once a month, throughout the dormant season. In spring, once the danger of frost has passed, Smith advises gardeners to “bring plants outdoors, refresh potting soil, and gradually begin watering and feeding once growth has resumed.”
Of course, there’s the age-old custom of simply bringing tender plants indoors and filling every sunny windowsill — and by sun, I mean light, because, you know, winter. But, in addition to low light levels and limited space, it can be challenging to maintain healthy growth with indoor heating. Most outdoor plants appreciate cool overnight temperatures, so turn down the thermostat (and put on a sweater). Avoid placing plants near drying heater vents, and boost humidity by grouping containers on a shallow tray of pebbles and water.
Cuttings of plants such as coleus, sweet potato vine and plectranthus make living bouquets and possibly new plants for next year. Simply snip several stems; pinch out any flowering tips; remove lower leaves; and plunk them in a jar of water, where roots will form readily. Over the next several months, watch for pests, and refresh the water regularly.
Toward the end of winter, most of your cuttings in water will have grown lanky and wan. Because roots that are formed in water don’t readily adapt to growing in soil, remove the top 3 to 4 inches of the freshest growth, and “stick” your new cutting in a container of moist potting mix to hopefully produce the next generation of garden plants. We’ll discuss taking cuttings and making more plants at a future date. We gardeners are always looking forward.