Jade McgeeEvery autumn, the same question circulates in plant-parent conversations: should I keep feeding my houseplants through winter, or stop entirely? The answer depends on what the plant is actually doing, and the honest answer is that most of the time, less is right.
Why winter changes things
Most houseplants slow down significantly in winter in response to reduced light and cooler temperatures. On the Highveld, this affects indoor plants from roughly June through August, when days are short and natural light through windows is weaker even on clear days. When plants aren’t actively growing, they don’t need the same level of nutrients they require during spring and summer.
Applying fertiliser to a plant that isn’t growing is the equivalent of serving a full meal to someone who’s asleep. The nutrients have nowhere to go, accumulate as mineral salts in the soil and can eventually burn the roots, causing the very damage you’re hoping to prevent.
The case for stopping altogether
For most standard houseplants kept in natural light indoors, stopping fertiliser from early autumn through to the first signs of new spring growth is the right approach. Plants like pothos, snake plants, peace lilies and philodendrons that visibly slow their growth in winter will do better with a clean break from feeding. The rule is simple: if you’re not seeing new leaves, stop adding nutrients.
The exception: actively growing plants
The rule changes if your plants are growing under artificial grow lights, or if you keep your home warm enough that certain tropical varieties continue producing new leaves through winter. If you can see fresh, unfurling foliage, the plant has the capacity to use a small amount of fertiliser.
For plants that continue growing in winter, reduce your usual liquid fertiliser to half the recommended strength and apply less frequently than you would in summer. A monthly feed at half strength during winter, compared to a fortnightly feed at full strength during spring and summer, is a sensible adjustment that supports growth without overwhelming a plant in slower mode.
Signs you’ve overfed in winter
The consequences of over-fertilising in winter are recognisable. New growth that appears thin, pale and leggy rather than full and healthy, leaves that show tip burn or browning at the edges, and a white crust forming on the soil surface are all signs that mineral salts have accumulated. If you notice this, flush the soil by watering several times thoroughly in succession and withholding fertiliser for at least a month.
When to restart
The signal to resume regular feeding is visual, not calendar-based. Fresh, pale green new leaves unfurling from the growing tips indicate the plant is re-entering its active phase. In most SA Highveld homes, this happens in August or September as day length increases and ambient temperatures begin to rise. For plants near south-facing windows with limited light, this signal may come later than for those near north-facing ones.
What you should do instead
For the period between now and that signal, the most useful things you can do for your indoor plants aren’t about feeding at all. Wipe the leaves clean with a damp cloth to remove dust and improve the plant’s ability to photosynthesise in low winter light. Check under leaves for pests, which become harder to spot and treat when growth is slow. Make sure each plant is in the best available light position for the season, and resist the urge to water too frequently on the assumption that more attention equals better care.
ALSO SEE:
Featured Image: Pexels
