The essentials of humidity

The essentials of humidity

Most houseplants with their sultry leaves that make our lives feel tropical and fabulous, originate from jungles and rainforest environments. Think exotic holiday destinations like Panama, the Caribbean and Southeast Asia. If you’ve ever been to Thailand (or even Durban) and noticed your hair frizzing and going wild – well, that’s humidity for you.
The average humidity of a rainforest is 77-88%. Most houseplants need humidity levels of 60%, like the Chinese Evergreen, which originates from Sri Lanka and the tropical forests of southern China, and the Begonia Rex, hailing from southern India.
Desert plants such as cacti and succulents including your String of Pearls and Snake Plants will tolerate much lower humidity, around 30-35% but sometimes as low as 20%.
how to increase plant humidity

 Humidity guide

  • 80% - 90%: Unless you're trekking in Borneo or documenting rare frog species in the Amazon, you're not likely to encounter the kind of humidity levels that make your glasses mist up.   
  • 60% - 80%: This is the ideal level. Our KZN coastal regions average around 76% humidity, Cape Town 70% (dropping in summer), and Gauteng around 68% in summer, dropping to 50% in winter. 
  • 40% - 60%:You'll find most homes are about this level, which the majority of plants thrive in. Certain plants will need some assistance, particularly those in Gauteng homes during the dry Highveld winters! Remember the humidity in offices is likely to be less due to air-conditioning. Our selection of office plants are more immune to dry conditions. 
  • 10% - 40%: Below 40% is becoming very dry and is likely to be the levels indoors when central and artificial heating is being used. Your cacti and succulents will be fine, but other plants will need help.

You can use a hygrometer to measure humidity levels.

The science behind humidity

Plant leaves are covered in stomata, tiny pores through which the plant breathes during transpiration. Water changes to vapour and is released into the atmosphere, while the plant takes in carbon dioxide for photosynthesis. During this process the plant loses water through its pores and needs to quickly replace lost H20 before the leaves crisp up. Sometimes it can’t always replace this lost moisture fast enough through the roots.

Transpiration is the process by which moisture is carried through plants from roots to small pores on the underside of leaves.  

Generally: The thinner the leaf, the greater its need for humidity (think Aglaeonema, Maidenhair fern). Thick, leathery or waxy leaves, or those covered with hair, are usually relatively immune to dry air (Rubber Plant, Draceana) 

Watch out for: Symptoms of dry air include curled leaves and dry leaf tips. 

How to raise humidity.

Misting with a water bottle

One of the easiest ways to raise the humidity around your plant is to mist its leaves with a spray bottle filled with water. Some plant gurus say this does not help your plant (and is more beneficial as therapy for humans). But at Atrium Plants headquarters we've tried and tested this method and found it to be successful.

For it to work, you must mist the leaves enough so that the water actually drips off them and they are completely wet. Misting like you’re spritzing yourself with L’Eau Issey Miyake Pure Nectar won’t help. You gotta spray, like hair spray when you want your hairdo to stay put during a whole night of dancing kinda spray!

By wetting the leaves well once a day (preferably in the morning to prevent fungal disease), it gives the stomata a chance to absorb moisture.

Invest in a humidifier

Besides keeping your plants healthy, humidifiers have loads of benefits for us humans including: reducing asthma, keeping skin and hair vibrant and moist, easing sinus congestion, purifying the air of pollutants and reducing cases of flu.

A 2013 study in a medical journal showed that increasing humidity levels to 43% or above significantly reduced the ability of airborne viruses to cause flu infections. In fact, in a low humidity environment, more than 70% of viruses transmitted diseases through coughing. 

Place on a tray of pebbles

How to increase humidity for houseplantsBy placing plants on a tray of water with pebbles, gravel or stones you raise the humidity around the plant’s immediate environment, creating a more humid micro-climate. Fill the tray with water, without letting the water cover the tops of the pebbles. Place your plant on the pebbles.

The reason the water must not cover the tops of the stones is because you don't want your plant sitting in water, which can cause root rot. It's better for it to be slightly elevated above the water. The H20, however, will create humidity. The down side of this method is that it doesn’t always look super stylish.

If you’re placing plants in a row you can use a trendy tray, or cluster plants together behind a couch where it will obscure the view of the pebble trays. Or you can make the pebbles part of the display using stunning decorative stones.

LECA stones

Our LECA stones are a great way to increase humidity levels. Place them at the bottom of your decorative pot, underneath the grow pot. The pumice is highly absorbent, which not only prevents water from pooling in the pot, the absorbed water is retained by the pumice, increasing humidity around the plant. This method also looks much neater, as you can’t see the stones hidden at the bottom of the decorative pot.


By placing peat moss dunked in water, in between the little gap between the grow pot and the decorative planter, you can increase humidity even further. It’s also an ‘invisible’ method.

Friends with benefits

Probably the best way to raise humidity levels is to group plants together. When a plant releases moisture through breathing, its neighbour absorbs it – a bit like kissing catches. What’s more, plant groupings look great! And this is a practical way to ensure plants are ok during holidays or time away.