Achieve Jungle-Like Humidity for Your Plants (Without a Hint of Mould!)

Our unique climate throws some serious curveballs at indoor plant enthusiasts. During our scorching summers, air conditioning sucks moisture out faster than a bushfire, while winter heating systems can drop indoor humidity to sahara-like levels. Your tropical mates—calatheas, ferns, and philodendrons—are used to steamy rainforest conditions sitting around 60-80% humidity, but most Aussie homes hover around a measly 30-40%.

This isn't just about plant aesthetics. When humidity drops too low, plants become stressed, making them vulnerable to pests like spider mites and scale insects—creating a cycle where frustrated gardeners reach for chemical sprays that can compromise family health.

The Family-Safe Humidity Solution

Perlite Tray Magic

This dead-simple technique can boost humidity by up to 15% around your plants using completely natural materials. Here's why it works brilliantly in Australian conditions:

What you'll need:

  • A wide, shallow tray

  • Perlite (medium grade) - those lightweight volcanic glass pebbles that won't harbour bacteria

  • Clean water

The setup:

  1. Fill your tray with perlite—it's naturally antimicrobial and won't go mouldy like regular stones

  2. Add water until it sits just below the perlite surface

  3. Place your plant pot on top (the pot bottom shouldn't touch water)

  4. Watch the magic happen as water evaporates slowly, creating a perfect microclimate

The beauty of perlite is that it's sterile, lightweight, and designed for plant use—no nasty chemicals or treatments that could affect your family's air quality.

Create Your Own Indoor Jungle Cluster

Plants are natural air purifiers and humidity generators through transpiration. Grouping your tropical plants together amplifies this effect, creating a self-sustaining humid microenvironment that benefits everyone:

For your plants: Higher humidity means healthier growth and natural pest resistance For your family: More oxygen production and natural air filtration For your wallet: Reduced need for expensive, energy-hungry humidifiers

The Mould Prevention Game Plan

Here's where many plant parents get nervous about increasing humidity—and rightfully so. Mould can be a serious health concern, especially for family members with respiratory sensitivities. The key is creating moving humidity, not stagnant moisture.

Smart Airflow Solutions

Gentle circulation is your best mate here. A quality clip-on fan positioned to create gentle air movement around your plant cluster prevents stagnant air while maintaining that precious humidity. This isn't about creating a windstorm—just enough movement to keep things fresh.

Strategic spacing matters too. Keep plants at least 10-15cm away from walls and furniture. This simple trick allows air to circulate naturally and prevents moisture from building up in corners where mould loves to set up camp.

Monitor Like a Pro

Guesswork is the enemy of both plant health and family safety. A decent temperature and humidity monitor takes the guesswork out completely. You're aiming for that sweet spot of 50-60% humidity—high enough for tropical plants to thrive, but not so high that you're inviting mould problems.

Pro tip: If you're seeing condensation on windows or walls, you've gone too far. Scale back the humidity sources and increase air circulation.

The Australian Advantage

Seasonal timing is everything in our climate. Right now, as we head into the warmer months, your plants are naturally more active and can handle—actually crave—higher humidity levels. This is the perfect time to establish these humidity-boosting habits before the harsh summer air conditioning kicks in.

Your tropical plants will reward you with:

  • Larger, more vibrant leaves

  • Natural resistance to common pests

  • Faster, healthier growth

  • Those Instagram-worthy unfurling moments we all love

Beyond Plant Health: Family Benefits

Creating optimal humidity isn't just about plant care—it's about creating a healthier home environment. Proper humidity levels can help with:

  • Reducing dry skin and respiratory irritation during our harsh summers

  • Natural dust control (humid air traps airborne particles)

  • Lower static electricity (ever noticed how your clothes stick together more in dry weather?)


Start simple: Grab some perlite and set up your first humidity tray this weekend. Add a basic monitoring system to track your progress, and consider a gentle fan for air circulation if you're grouping multiple plants.

The result? Lush, thriving tropical plants that contribute to a healthier home environment—all achieved naturally, without compromising your family's wellbeing or breaking the bank on expensive equipment.


About the Author

Scott Cheney - Dr Greenthumbs
Scott Cheney is the Director and Founder of Dr Greenthumbs, with over a decade of hands-on experience in organic gardening. Growing up in rural NSW, Scott’s passion for unusual plants – from cacti to entheogens – evolved into a full-blown commitment to chemical-free gardening when he bought his first property in Wollongong. For the past 8 years running Dr Greenthumbs, Scott has developed unique, first-to-market products like TurboDirt Water Only soil and 100% dry amendment fertiliser blends. When he’s not testing new mixes, you’ll find him swapping gardening tips like your local mate, not giving the hard sell.