It may seem that mid-January is a slow month for gardeners, but whoever has fruit trees, rose bushes, flowering shrubs, and grasses to prune knows that the next few weeks are busy ones outdoors. With weeds popping up at every turn, there is always something to do as long as the weather cooperates.
Indoor gardening has its own concerns in winter, too. Houseplants that need little attention and look lovely during most of the year now need special monitoring. Left untended, they may suddenly take a turn for the worse.
During very cold weather, especially at night after the furnace is turned down, indoor air can damage some tropical plants that we routinely grow quite safely in our homes.
Leaves on some — such as philodendron, pothos and dracaena — will turn black very quickly when surrounding air becomes too cold. Plants survive loss of foliage, but their appearance suffers. Begonias, African violets, and other soft-stemmed plants may show limp foliage that refuses to plump up again and instead slowly droops further before falling off.
Damage usually occurs on plants placed very close to a window or entry door, along an outside wall or in an unheated room.
It may seem prudent to place houseplants in front of a window in winter so they benefit from sunlight and heat, but this actually subjects plants to several threats.
Damage can come from too much cold at night and excessive sun during the day. This time of year, bright sunlight streams into our homes at a lower angle than in other seasons, yet is strong enough to burn foliage.
If you've moved a plant from its usual place to sit in or away from a window, this seemingly minor change in environment may cause leaf drop independent of variations in sunlight and temperature. Many plants simply resent change and let you know by drooping, shriveling or dropping leaves.
Drafts from opening doors or air movement from a heating vent can also wreak havoc with a temperamental plant, especially one in bloom fresh from the florist.
Evergreen weeping figs (Ficus benjamina) are among the most sensitive plants. They're known to drop leaves as soon as you buy them or when they're moved from one room to another. Some leaf drop is normal, often at this time of year. When you notice it happening, water less frequently — although the soil should never dry completely — and wait to fertilize until new growth begins.