December 5th: Let There Be Light
During the next month or so, those of us in Northern Hemisphere will be experiencing our darkest days of the year; not emotionally, one hopes, but in terms of daylight hours. Many of us respond negatively to lack of sunlight and cold temperatures and the same can be said of treasured house plants. Windowsills, porches and conservatories we regard as bright and sunny during spring, summer and autumn, might well be shaded and dark for the next few weeks, especially if the prevailing weather is dull. Winter sun is weak and low in the sky, so if you live in a built-up area, a valley or have trees and hedges close to the house, its pale rays might not reach you again until spring. Inside our cosy homes, we should not underestimate the amount of useful light that is filtered out by just a single thickness of glass, nor how rapidly the quality of light diminishes as one moves away from a window.
The house plants most at risk of sulking during the winter are those that demand full, direct sunlight such as pelargoniums, hibiscus, kalanchoe, mandevilla, coleus, most herbs and many succulents. In November I move these to my sunniest south and east facing windowsills and position them as close as I can to the glass without allowing them to touch it: condensation on the foliage can cause outbreaks of grey mould. If you can’t give these sun-loving plants the light they crave then no amount of mollycoddling will help them. They will sulk, grow leggy, lose leaves, turn pale and either die or go dormant. Not a good look.
If sunny windowsills are lacking in your home then there are plenty of plants that will cope with low light, which can be defined as light sufficient to read a newspaper during the daytime. Low light will exist within 2ft of north-facing window or 6ft of a south-facing window. Here you will find that aspidistras, philodendrons, monstera (cheese plant), spathiphyllum (peace lily) and sanseveria (mother-in-law’s tongue) cope pretty well. In bright shade, i.e. good light but away from the sun’s direct rays, the choice of plants expands greatly to include phalaenopsis orchids, palms, calatheas, peperomias, streptocarpus, bromeliads, alocasias, ferns and so on. These are mostly non-flowering, but have risen in popularity on the recent tidal wave of interest in house plants. I cannot image living in a home without plants, and unless you live in a dungeon or a cave there’s no reason why anyone should have to.
The key thing to remember is that house plants need a brighter aspect during winter than they do at other times of year, so they may appreciate a temporary move. Avoid a dry atmosphere by placing plants on a tray of damp pebbles or grit, but don’t, on any account, let them stand in water. Protect plants from fluctuations in temperature (for example don’t draw the curtains so that they are trapped between an insulating curtain and cold glass at night) and be aware of draughts, which most houseplants detest as much as humans do.
Given a little care and attention houseplants should not only survive the darkest days, but be primed and ready to put on a growth spurt once the spring arrives. TFG.