When it comes to houseplants, the right humidity is a game changer. Whilst thick, humid air isn’t so good for that new hair-do, most of your favourite floras originate from humid rainforests, so they need moisture in the air to keep them lush and healthy.
How humid does it need to be?
Every plant is different. Not all plants need high humidity, some can survive in dry conditions, like cacti and succulents — they grow in arid environments, so won’t need as much moisture as plants that grow in rainforests. A very general tip to follow is to look at the leaves. The thinner the leaf, the greater its need for humidity. Thick, leathery, or waxy leaves, or those covered with hair, are usually relatively immune to dry air.
Most the tropical varieties of houseplants (like Alocasias), and those that grow near water (like ferns) will need high levels of moisture to survive. The average home usually has around 20% humidity, so here are some tips to crank that up to 40-60%!
Use a pebble tray
A quick and easy way to raise humidity instantly around your plants. Fill a clean tray with at least an inch of pebbles or stones, then place your plants on top of the pebbles. Fill the tray with water, making sure the water doesn’t actually touch the bottom of the plants — this can lead to root rot, which you want to avoid. Aim for about halfway up the pebbles. As the water in the tray evaporates, it increases the moisture in the air around the plant. Top up the water level regularly, and make sure you empty and rinse the tray every time you flush your plants. This will stop insects from breeding and reduce the concentration of fertiliser salts that have accumulated in the tray.
Give your green babes a weekly mist
Most plants appreciate a weekly mist, especially when heaters and air conditioners are involved! Misting your plants exposes the leaves and soil to water particles which will evaporate and raise the humidity.
Try to mist once a day in dry periods. You can add our Grow Concentrate to the water for an added boost! Just bear in mind that some plants should never be misted, including any plants with hairy or velvety leaves, like African violets.
Group your plants together
Just like humans, plants sweat. They release moisture through their leaves in a process called transpiration. So, a clever trick is to group the plants together in the same space. When they’re next to each other, the evaporation creates a more humid microclimate as they transpire (sweat) water through their leaves.
Place a cloche over your plant
By placing a cloche — also known as bell jars, or terrariums — over your plant, you’re creating a humid mini-climate for it to grow in. The moisture that the plant releases will stay within the cloche, creating condensation that is then reabsorbed by the plant. This keeps the humidity high around your plant constantly. If you have smaller plants that need high humidity, this is the perfect solution. And they look pretty cool too.
Just remember to size up rather than down, as your plant needs to have room to grow, and be sure to remove it for a few hours a day to allow your plant to get air flow. Do not place plants with cloches in direct sunlight. The glass acts as a magnifying glass when it’s hit by the sun, so the temperature will rise quickly and scorch the plant. Stick to indirect light, and your tropical plants will flourish under their new steamy setting.
Try the bathroom hack
Find the most humid spot in the house for your tropical loves. The most humid position is usually in the bathroom, but it must be very brightly lit with natural light from a skylight or windows for plants to grow successfully. Near a kettle is also a good one; but be careful, as steam and heat can damage the leaves (we’ve learnt the hard way)!
Invest in a humidifier
Humidifiers improve the indoor air quality so that you can breathe much more easily. But not only are they good for you, they double up as a great humidifier for your plants too, as the mist they release creates a humid environment for your plants to grow. For best results, place the humidifier next to your plants and let it run. Too easy.
Why do plants need humidity?
Humidity is the amount of water vapour that’s present in the air. When it’s high there’s more moisture — you know those stifling hot summer days when you just CAN’T cool down?! Our hair turns into a giant ball of frizz, and we feel uncomfortably hot and sweaty. It’s hard to cool off when it’s humid because your sweat can’t evaporate into the air like it needs to.
When it’s low, there’s less moisture, so the air is much drier. This is one of the biggest reasons we suffer from dry skin during the colder winter months.
Plants react in the same way. Plants evaporate water in order to cool themselves and to discharge waste. Humidity influences the amount of water it can evaporate through its leaves (this determines the plant’s health). They need humidity because the pores they breathe through lose most of their moisture when the surrounding air is dry. And some plants find it difficult to replace that loss through the water its roots absorb.
If the humidity is too high, plants can’t evaporate their water vapour. If the humidity is too low, they evaporate too much water causing it to dry out, much like our skin does in winter. And don’t forget we love to crank up the heating during the colder months, which means your green babes will suffer even more — you’ll notice the tips of the leaves start to curl, and they can often turn crisp and brown. These are telltale signs your plants are in need of a humidity boost.