We’re heading into autumn now in Melbourne. Days are getting shorter, temperatures are dropping (eventually - Melbourne’s autumn can be unpredictable), and your plants need different care than they did in summer.

Here’s what to change and what to watch for as we transition from March through May.

Watering Adjustments

This is the biggest change you’ll need to make.

Reduce watering frequency: Plants use less water in cooler temperatures with shorter days. What needed weekly watering in summer might only need water every 10-14 days now.

Check soil before watering: Even more important than in summer. Stick your finger 5cm into soil - if it’s still moist, wait. Overwatering kills more plants in autumn and winter than any other time.

Empty saucers promptly: Sitting in water causes root rot, especially in cooler temperatures when soil dries slower.

Morning watering is better: Gives excess moisture time to evaporate during the day rather than sitting wet overnight.

Light Considerations

Sun angle drops: North-facing windows get more sun as the sun moves lower in the sky. What was bright indirect light in summer might get direct sun in autumn/winter.

Day length shortens: By late May, we’re down to about 10 hours of daylight. Plants near windows still get adequate light, but plants farther into rooms might struggle.

Consider relocating plants: Move light-hungry plants closer to windows. Move plants that got too much summer sun slightly back or to less intense windows.

Watch for leggy growth: Sign that plants aren’t getting enough light. Move them closer to windows or supplement with grow lights.

Temperature Management

Melbourne autumn is unpredictable. We might have 28°C days in March or 12°C days in April. Plants cope better with gradual changes than sudden swings.

Keep plants away from heaters: Most houseplants handle cooler temperatures fine (down to about 15°C), but dry heat from heaters damages them.

Watch for cold windows: If you’re getting cold nights, windows can create cold spots. Move sensitive plants slightly away from windows on cold nights.

Indoor temps of 15-22°C are fine: Most common houseplants handle this range comfortably.

Bring tender outdoor plants inside: If you’ve had plants on balconies or patios through summer, start thinking about bringing them in before first frost (usually May in Melbourne).

Fertilising Changes

Reduce or stop fertilising: Most plants slow or stop growing in autumn. They need less nutrients.

Last feed in early April: I give plants one final feed in early autumn, then stop until spring.

Don’t fertilise struggling plants: Fertiliser doesn’t fix problems caused by light, water, or temperature issues. It can make things worse.

Growth Expectations

Slower growth is normal: Don’t panic if plants stop putting out new leaves. They’re entering dormancy or semi-dormancy.

Some plants go fully dormant: Certain plants (like caladiums) might die back completely. This is normal, not plant death.

Flowering changes: Many houseplants flower in response to day length. Some might bloom now (peace lilies sometimes do), others won’t flower until spring returns.

Pest Watch

Autumn often brings pest increases as outdoor insects look for warm indoor spaces.

Common autumn pests:

• Fungus gnats (from overwatering in cooling weather)
• Spider mites (from dry indoor heating)
• Scale insects (moving indoors with plants from outside)

Prevention:

• Check plants thoroughly when bringing them inside
• Don’t overwater
• Maintain some humidity (heating dries indoor air)
• Inspect plants weekly for early pest detection

Humidity Management

Melbourne’s autumn air is generally moderate humidity, but indoor heating drops it significantly.

Signs of low humidity:

• Brown leaf tips and edges
• Crispy leaves despite adequate watering
• Spider mite infestations

Solutions:

• Group plants together (creates microclimate)
• Pebble trays under pots
• Keep plants away from direct heating vents
• Humidifiers if you’re serious (and have many plants)
• Misting is mostly ineffective, don’t bother

Repotting Decisions

Avoid repotting in autumn: Plants are slowing growth. They don’t establish roots well in cooling weather.

Wait until spring: Unless a plant is severely rootbound or has root rot, repotting can wait until September/October.

Exception: If you must repot, keep the plant in similar-sized pot and disturb roots minimally.

Pruning and Maintenance

Clean up summer growth: Remove dead or damaged leaves. Prune overgrown plants to manageable size.

Don’t do heavy pruning: Major pruning stimulates new growth, which won’t develop properly in low light and cooler temps.

Dust leaves: Shorter days mean plants need maximum light. Dust on leaves blocks it. Wipe them down with damp cloth.

Plant-Specific Autumn Care

Ferns: Often struggle in autumn with drier indoor air. Increase humidity, reduce watering, keep away from heaters.

Succulents and cacti: Enter dormancy. Water much less frequently (monthly or less). They tolerate cooler temps well.

Tropical plants (monstera, philodendron, pothos): Reduce water, maintain warmth (above 15°C), watch for slower growth.

Flowering plants: Many stop flowering. This is normal. Continue basic care, they’ll bloom again in spring.

Outdoor Plant Decisions

Frost-tender plants: Bring inside before first frost. This includes most succulents (except some sedums), tropical plants, and anything you’re not willing to lose.

Hardy plants: Can stay outside through Melbourne winter. This includes many Australian natives, established perennials, and cold-hardy succulents.

Timing: Watch weather forecasts in late April and May. Bring tender plants in before overnight temps drop to 5°C or below.

Common Autumn Problems

Yellowing leaves: Often from overwatering in cooler weather. Reduce watering frequency.

Leaf drop: Some plants (ficus, especially) drop leaves in response to changing light and temperature. Usually not fatal, but annoying.

No growth: Normal. Don’t try to force growth with fertiliser or extra water.

Crispy leaves: Usually low humidity from indoor heating. Increase humidity, move plants away from heat vents.

Shopping for Plants

Autumn is actually a decent time to buy plants in Melbourne:

Pros:

• Nurseries often have sales
• Plants are hardening off for winter (more resilient)
• Cooler weather makes transport easier

Cons:

• Limited selection compared to spring
• New plants won’t grow much until spring
• Higher risk if you buy stressed plants

If you buy plants now, quarantine them from your collection for a few weeks to check for pests.

Planning Ahead

Use autumn to plan for spring:

Note what worked: Which plants thrived, which struggled, which locations worked well.

Research new plants: Figure out what you want to add in spring when selection improves.

Prepare supplies: Buy pots, soil, fertiliser when they’re on sale.

Clean and organise: Sort through supplies, toss expired products, clean pots for reuse.

The Bottom Line

Autumn plant care is about doing less, not more. Water less, fertilise less, expect less growth.

The main risks are overwatering and cold damage. Avoid both by checking soil moisture carefully and keeping plants away from extreme temperature spots.

Most common houseplants handle Melbourne’s autumn fine. They’ll slow down, maybe look less impressive than summer peak, but they’ll be fine.

Spring will come (even if Melbourne’s winter feels endless), and plants will perk up again.

Next post I’m planning to cover propagation techniques in detail - how to multiply your plants for free. Autumn is actually decent timing for some types of propagation.

For Melbourne-specific seasonal gardening information, Gardening Australia has good regional guides, though they focus more on outdoor gardening than houseplants.