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Plantiful tips for “overwintering”

by Timber Press on October 13, 2016

in Design, Gardening


A tillandsia and a few rabbit’s foot ferns thrive in the light and humidity of an east-facing windowsill above the kitchen sink.

The range of effort required to keep tender plants alive over the winter varies from really easy to not difficult at all. What you’ll be capable of depends on how much you can lift without injury, how much control you have over the indoor climate, and how much space is available. Enjoy these tips and tricks for “overwintering” from Kristin Green‘s Plantiful: Start Small, Grow Big with 150 Plants That Spread, Self-Sow, and Overwinter.

During the winter, you can store and enjoy plants in three kinds of spaces. Some plants prefer to keep growing, and even blooming, indoors on warm windowsills. More will be happy to slow down to a standstill in a space that is bright and chilly but above freezing, such as a greenhouse, cold frame, or enclosed porch. And others will willingly go dormant in cool, dark storage.

Locating light

Even in houses with covetable natural light, daylight is elusive during the winter. The sun, low on the horizon, weakens in intensity, and glass lets in less light than you might think. Add to that, most of us who desire privacy have also covered our windows either with foundation shrubs or curtains.

  • South-facing windows provide the brightest overall exposure through the winter (in the Northern hemisphere) so reserve those windowsills for sun-loving succulents, geraniums, and citrus.
  • West-facing windows offer a warm afternoon glow. This is a fine second choice for tropical plants like hibiscus and glory bush.
  • East-facing windows, with their morning sun, give a gentle boost to cuttings and seedlings.
  • North-facing windows deliver diffuse light that will be fine for most ferns and understory plants like aspidistra and farfugium. But when the sun is distant and weak even shade-loving plants like these would do well in an east-facing window, or away from the windows in a bright room with southern or western exposure.


Time it right: coming in for winter

The timing of the move inside can mean the difference between life and death. In fall, scan the weather forecasts for frost warnings and play it safe. Start bringing your tropical plants inside as soon as night temperatures are forecast to dip into the mid-50s F. If temperatures plunge quickly in your area, plan ahead and give the plants destined for the living room a chance to acclimate by bringing them inside two weeks or so before you close windows and turn on the heat.

Winter watering

Judging the amount of water to give plants is probably the trickiest variable for most indoor gardeners. When getting to know your plants, think about where they grow wild. Plants from a rainforest floor will need to be kept evenly moist, which means the soil
should never be allowed to dry out. But that doesn’t mean they should sit constantly in a full dish of water; only plants from a bog habitat will tolerate that. Plants from climates with limited rainfall do better if their soil dries to the touch between watering. Their leaves may even be allowed to wilt, but then we have to drench them. And we have to pay attention to any seasonal watering requirements too. Many plants’ dormant season is a dry one. Plants send out distress signals when they need water but they will become stressed and unhealthy if wilting is the only cue you use. Instead, make a habit of checking their soil a few times a week.

You’ll see indicators by looking at the potting soil (it lightens in color as it dries) and sticking your finger in it (the soil will either feel cool and moist, or dry and dusty, to the touch). But the best way to test for soil dryness beyond the surface is to test its weight. If the pot and plant feel heavy, the soil is moist; if it feels light, it’s dry. Water plants in the morning so they can take advantage of the day’s light to pull water up into their leaves through photosynthesis. Always water thoroughly enough that it runs out the drainage hole at the bottom of the pot. (This will encourage the roots to grow down rather than staying near the surface.)

Allow your plants to sit in puddled saucers for a few hours to give the soil and roots a chance to absorb what’s needed, then empty the excess. The warmer the temperature, outside or in, and the brighter the light, the more often plants will need to be watered. And vice versa: the cooler the temperature, the lower the light, the slower the growth, the less water is required. Many plants have phototropic hormones in their stems that cause them to lean toward the sun, so rotate them a quarter turn every time you water to keep them balanced and standing straight.

green_k-sKristin Green first unearthed a passion for gardening while on the West Coast earning degrees in art and painting from the University of Washington. Now back on native soil, she is a full-time, year-round gardener serving as interpretive horticulturist, garden blogger, and photographer at Blithewold Mansion, Gardens & Arboretum, a 33-acre non-profit public garden in Bristol, Rhode Island.


Click image for a look inside this book.

“A delightful new book. . . . filled with gardening tips and inspiring color photos of plants and gardens.” —Orange County Register

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