Light
Winter light and where your plants should sit
Between the autumn and spring equinoxes, the angle and length of daylight across Canada change far more than most indoor growers expect. A windowsill that delivered bright, indirect light in summer can fall into deep shade by December. This guide explains why, and how to respond without buying anything.
Why winter light is weaker, not just shorter
Two things happen at once. Daylight hours shrink, and the sun tracks low across the southern sky. In southern Canadian cities, daylight near the December solstice runs to roughly eight to nine hours, and the low sun angle means light enters windows at a shallow slant for a short part of the day. Cloud cover through late autumn and winter reduces it further.
The practical result is that the usable bright zone inside a room shrinks toward the glass. A plant that sat comfortably a couple of metres back in July may be in functional shade by midwinter.
Read the window, not the calendar
Window orientation decides how much light each room receives:
| Exposure | Winter character | Suits |
|---|---|---|
| South | Strongest and longest direct light of the year | Most foliage; cacti and succulents |
| East | Gentle morning light, cooler afternoons | Pothos, peace lily, ferns |
| West | Stronger afternoon light, more temperature swing | Snake plant, ZZ plant, jade |
| North | Indirect and dim all season | Tolerant low-light foliage only |
A simple winter relocation plan
You do not need light meters. Use this sequence as the days shorten in October and November:
- Move light-hungry plants (most flowering and variegated foliage) closer to south- or west-facing glass.
- Pull foliage back a hand's width from the pane so leaves do not touch cold glass overnight.
- Rotate each pot a quarter turn weekly so growth stays even rather than leaning.
- Keep low-light tolerant plants where they are; moving them rarely helps and can stress them.
The shadow test. On a bright midday, hold your hand a step back from where the plant sits. A crisp, well-defined shadow means usable direct light; a soft, faint shadow means the spot is low light. It is a quick way to compare locations without equipment.
Reading the plant for too little light
Plants signal insufficient winter light before they decline seriously:
- New leaves emerge smaller and spaced farther apart on the stem.
- Stems stretch and lean noticeably toward the window.
- Variegated leaves fade toward plain green as the plant tries to capture more light.
If you see these, move the plant closer to the brightest window before considering supplemental lighting. Many issues resolve with placement alone.
A note on supplemental light
If a room simply has no bright window, a basic full-spectrum grow light on a timer can carry plants through the darkest months. Treat it as a last step rather than a first one, and position it close enough to cast a clear shadow on the foliage below.
What to expect by spring
As daylight lengthens through February and March, the usable bright zone expands back into the room. This is the moment to reverse the winter moves gradually — shifting plants away from intense glass over a week or two so new growth is not shocked by the stronger returning sun.