For half a century, scientists have been carrying out experiments to show the world that plants are good for our health and happiness. That’s a lots of experiments.

Let’s start with trees

There are four big benefits of putting tree in your yard or having them in your street.

Shade & cooling

Trees are the most environmentally friendly way to shade and cool your home. Growing trees to shade certain windows, walls and many common materials with high thermal mass (eg. cement, bitchumen, bricks) will help block heat and act as a living air conditioner. In this way, they improve the thermal comfort of your home, reduce your electricity bill and make your suburb a cooler place to live.

Places to ride & run

In need of some fresh air? Being active in outdoor green spaces is good for our health and wellbeing. Exercise is best performed in tree shaded spaces, to get the benefits of both cooler spaces and the proven mental health benefits of being around nature. Remember that trees produce oxygen, so next time you’re exercising near a tree, give it a high-five. 

Wildlife habitat

Trees provide critical habitat for wildlife, including birds. Many creatures we share the planet with depend on trees for shade, food, and shelter. In a mutually beneficial relationship, wildlife eat many insects and weeds that may not be welcome in your garden. Enjoy the birdsong and the beauty of living in a natural world by planting and protecting trees.

Aesthetics & value

Green is beautiful. People’s number one association with green is that it creates a great aesthetic. By planting trees, you’re inviting greenery, beauty and nature into your life. A leafy home is a beautiful home and trees add value. Having large trees in your yard or along your street increases the value of your home – not only raising the economic value of your home, but the biodiversity value too.

What about plants?

Plants are amazing too. Here’s what the science says about them.

Two big benefits

Air quality

Removing air-borne toxins created by paints, furniture finishes and air pollution. Just one or two plants starts to increase air quality significantly in a space.

Wellbeing

Creating feelings of relaxation, inspiration and positivity. The first few plants give a limited benefit, but once you start to create a look, wellbeing increases quickly. Variety of sizes and species is key.

JUST ONE PLANT CAN IMPROVE YOUR AIR 25%

And a few more can do a whole lot more. Plants absorb airborne pollutants, including:

25% CLEANER AIR

75% CLEANER AIR

MAXIMUM HEALTH & WELLNESS

In an average 4x5m space

WHAT ARE VOCS?

Organic chemicals are widely used in household products, including paints, furniture finishes and many cleaning products. Being volatile means they can easily become vapours or gasses, which contaminate our air. Concentrations of many VOCs are up to 10 times higher indoors than they are outdoors. And yes, they can be bad for your health.

Particulate matter, like ash and dust

Inorganic compounds, such as carbon monoxide

Volatile organic compounds: VOCs

A FEW PLANTS CAN MAKE YOU FEEL MORE RELAXED, INSPIRED AND POSITIVE

RMIT also investigated direct mental health benefits of plant, such as improved mood and concentration, and indirect benefits, such as productivity and positive social behaviour, that indoor plants might have caused.

They found that there is very little wellbeing benefit in just one plant, but once you start to create a ‘look’ in your space, wellbeing begins to increase significantly.

What’s more, complexity matters. The greater the mix of sizes and varietals, the greater the benefits.

In outdoor spaces such as yards and courtyards, plants have limited ability to improve air quality. However, a good array of plants will still improve wellbeing significantly.

A LITTLE BIT MORE MENTAL WELLBEING

60% MORE MENTAL WELLBEING

MAXIMUM HEALTH & WELLNESS

In an average 4x5m space

THE RATING SYSTEM

The rating system makes it easy to understand the health and wellbeing benefits at a glance for different sized rooms. These are all based on medium sized plants (around 30cm tall).

SMALL ROOM (3X3)

A LITTLE BIT MORE MENTAL WELLBEING
45% CLEANER AIR

50% MORE MENTAL WELLBEING
75% CLEANER AIR

MAXIMUM HEALTH & WELLNESS

MEDIUM ROOM (4X5)

A LITTLE BIT MORE MENTAL WELLBEING
25% CLEANER AIR

60% MORE MENTAL WELLBEING
75% CLEANER AIR

MAXIMUM HEALTH & WELLNESS

LARGE ROOM

A LITTLE BIT MORE MENTAL WELLBEING
25% CLEANER AIR

SIZE MATTERS

Size of a plant is important in its ability to improve your space. When it comes to air quality, total leaf are and total size of the rootball are important (so go for bigger leaves and bigger pots). As a rule of thumb, when considering the rating system above, discount smaller plants to be worth 1/3 of a medium plant. While large plants are worth 1.5 times a medium plant.

Small

Medium

Large

SPECIES MATTERS

The science above all works on an averaging method. It’s designed to be simple, to give you well estimated rules of thumb for improving your health and wellbeing. When it gets to the details, some plants are better at improving air quality than others. For that sort sort of level of information, ask the experts at your local nursery. NASA’s Clean Air Study also has good information.

Learn more

THE METHOD

RMIT studied 101 articles and research reports and crunched them into one easy-to-understand index. The studies looked at a plant’s ability to absorb airborne pollutants, such as particulate matter, inorganic compounds such as carbon monoxide, and volatile organic compounds – VOCs. RMIT also investigated direct mental health benefits of plant, such as improved mood and concentration, and indirect benefits, such as productivity and positive social behaviour, that indoor plants might have caused. All outcomes were taken through a peer-reviewed expert panel to ensure validity of the findings.

BASELINE APPROACH

As much as possible we used Best Available Scientific Evidence – BASEline – to determine the relationships between plants and health and wellbeing. Where our information was not adequate to contribute to the index, our expert panel estimated the most likely cause and effect relationships.