Indoor plants in Melbourne hit their hardest stretch of the year through May to August. The lower light, the colder windows, the warmer-than-natural ambient temperature from the heating, the lower humidity from the heating — all of these stress most indoor plants in ways summer never does. Here is what to do through autumn to set your plants up to make it through.

Reduce watering. Materially.

The single biggest cause of indoor plant death through winter is overwatering. The plant’s growth has slowed because the light is lower. The transpiration through the leaves is lower. The water demand from the roots is much lower than in summer. The same watering schedule that worked through January will rot your plant in July.

The realistic rule: water when the top inch or two of soil is dry to the touch, and then water thoroughly. The plant that was on a weekly water in summer is often on a fortnightly water through the worst of winter. Some plants — the snake plants, the ZZ plants, the cacti and succulents — will be on a monthly water or less.

The pot weight is a useful proxy. The pot that feels heavy from the moisture in the soil does not need water yet. The pot that feels noticeably lighter is ready.

Move plants to maximise light.

The light intensity inside most homes drops significantly through autumn and winter. The plant that was thriving 1.5 metres from a north-facing window in summer is in much darker conditions in May. The pattern I use:

Move plants closer to the window if they have space. The tropical foliage plants — monsteras, philodendrons, ficus — appreciate the extra light. The succulents and cacti definitely appreciate it.

Open the curtains during the day. The fabric curtains that are charming in the evening cut a lot of the daytime light. Get them out of the way during daylight hours.

Clean the window glass. The dust and grime on the inside of the window pane cuts more light than people realise. Wipe the windows down once a season.

Clean the plant leaves. The dust on the leaves cuts photosynthesis. A damp cloth wiped across the broad-leaf plants once a month helps materially.

Pay attention to draughts.

The plants near the windows in winter are exposed to cold draughts when the temperature drops outside. The plant that is happy 60cm from the window in summer can be stressed by the cold air spilling off the glass in July.

Tropical plants and tropical-foliage houseplants are particularly sensitive to draughts. Move them back from the window slightly through winter if you see leaf-yellowing or leaf-drop concentrated on the leaves nearest the window.

The plants near heating vents also struggle. The hot, dry air from a heating vent dehydrates the foliage faster than the plant can replace the moisture. Move plants away from heating outlets.

Address the humidity.

Centrally heated indoor air is dry. The humidity inside a Melbourne home through winter can drop to 20–30% relative humidity, which is genuinely low for many tropical-foliage plants. The plants most affected are the calatheas, the marantas, the alocasias, the maidenhair ferns — anything from a tropical rainforest origin.

The practical responses I have tried over the years:

Group plants together. The plants release moisture into the air around them through transpiration. A cluster of plants creates a microclimate with higher humidity than the room average.

Use a humidifier in the room with the most sensitive plants. A small ultrasonic humidifier running a few hours a day makes a meaningful difference. The bedroom-style humidifiers are fine for this.

Place plants on pebble trays. A shallow tray of water-covered pebbles under the pot adds local humidity as the water evaporates. The pot should sit on the pebbles, not in the water.

Mist the plants if you enjoy doing it. The misting alone has limited effect — the moisture evaporates quickly — but it does help if done regularly.

Hold off on fertiliser.

The plant in slow growth mode does not need much fertiliser. The fertiliser applied to a plant that cannot use it accumulates in the soil and damages the roots. Pause fertiliser application from late autumn through to early spring for most foliage houseplants.

The exception is plants that flower or actively grow through winter — the orchids, the hellebore-style bulbs, the cyclamen. These get light feeding in line with their active growth.

Watch for pests.

The dry winter conditions favour some indoor plant pests. Spider mites in particular thrive in dry, warm conditions. The thrips that came indoors in late autumn can build up significant populations through winter if uncontrolled.

The pattern for managing pests through winter:

Inspect plants weekly. Look at the undersides of leaves, the new growth, the stems. Catch infestations early before they spread.

The first response to most indoor pests is a thorough leaf wipe with a damp cloth, sometimes with a tiny amount of insecticidal soap. The early-stage infestation can often be controlled with two or three weekly leaf-wipe sessions.

For more established infestations, an insecticidal soap spray or a neem oil application is the next step. The systemic insecticide treatments are an option for the more stubborn cases.

Isolate any plant that has a pest problem from the rest of the collection until the problem is resolved.

The plants that thrive in winter conditions.

A few categories of indoor plants actually like Melbourne winter conditions:

Pothos and philodendron. The vining tropicals tolerate low light well and the lower water demand fits the season.

Snake plants and ZZ plants. The water-storing succulent characters mean they handle the reduced watering schedule effortlessly.

Most cacti and succulents. These are dormant or near-dormant through winter. They want bright light and minimal water — exactly what the indoor winter environment provides.

Hoyas. The semi-succulent foliage means they handle lower water and the slow growth pattern means winter does not bother them.

The plants to watch most carefully through winter are the calatheas, the maidenhair ferns, the alocasias, the fiddle leaf figs (the over-watering in winter killer), and the begonias.

The Melbourne winter is survivable for most well-tended indoor plants. The keys are reducing the water, maximising the light, managing the draughts, and adding some humidity. The plants that struggle most are usually the plants whose owners did not adjust their summer routine for winter. The plants that thrive are usually the plants whose owners noticed the season changing and adapted.