World Rainforest Day: Five Tips from our Indoor Rainforest

Beneath the Canopy took us and our visitors deep into the rainforest, surrounded by the sights and sounds of our tropical friends - the plants we know and recognise as houseplants, and the creatures that depend on them in their natural habitat. It was a feast for the eyes and the ears, but our main aim was to show visually and physically how the environment which has shaped these tropical houseplants is key to understanding how to care for them in our homes. While we can’t all recreate the Amazon Basin in our living rooms, knowing exactly what your plant has actually adapted to will, like as not, help you not to kill it.

It’s always important to us that we source and home our houseplants as sustainably as possible. We are still gradually selling the plants which made up our show garden in the shop, and each one that goes to its forever home is accompanied by detailed care information, and often a lecture from us on the key points of how to care for that plant. On the supply side, we ensure that none of our plants were actually grown in the rainforest. They come from commercial growers here in the UK and in Europe, which not only reduces air miles but also ensures we aren’t feeding into any markets for illegal plant poaching. There’s a lot to think about with all these tropical houseplants!

For today, I’m going to focus on our houseplant fundamentals from Malvern. We aimed to learn, from the rainforest itself, how air, water, light, temperature and nutrients interact and are so very key to keeping plants alive. We looked at these essentials in the rainforest, examining the habitat and conditions they have adapted to; and in our homes, thinking about how we can use this information to adapt our conditions for our favourite houseplants. So, here are five houseplants for five plant-growing essentials.

1. AIR

We all know why air is so important for us - and we’ve heard about the Amazon being the lungs of the world, so we know how key rainforest plants are in the delicate worldwide balance which creates the environments we all share.

But on the level that we need to be on for thinking about houseplants, the concentration of CO ₂ in the atmosphere isn’t quite what we’re looking at. We’re thinking more about good ol’ H ₂ O, and the movement of the air. And the plant I’m looking at here is the Philodendron - there are loads of different species, several of them included in our show garden, but today I’ll pick a vining one, Philodendron brandtianum. It’s on the rare side, with funky silvery patterns on the leaves. And it likes to climb, in its natural habitat, like most of its Genus - Philodendron literally means ‘tree-lover’, so named because it seems to hug the trees. Cute!

Like many rainforest plants, our Philodendron likes it best when it’s humid . That means plenty of moisture in the air, like after a hot shower or when something’s bubbling on the stove. This is why kitchens and bathrooms are often great places to keep humidity-loving plants! But the other thing that’s key with air is that it should be moving . There may be plenty of shelter in the rainforest, but it’s never deadly still - there will always be something moving, a breeze blowing, nearby water running. All of these tiny movements cause disturbances to the air and help it circulate, even while it’s so full of moisture. Your Philodendron is used to having not only its leaves but also lots of its roots out in the air, as it clings to tree trunks, so making sure the air is circulating helps the leaves and the roots to not get too bogged down and damp.

What does this mean at home? Well, if you’re keeping it in a steamy bathroom, make sure you have some ventilation in there too. Walking around will help move the air, and opening a window in whatever room your houseplants are in will add just a bit of a breeze. Take care in winter not to let it get too cold though. It’ll even be important if your plants are growing in a cabinet to keep higher humidity - some air circulation will always help them to not go totally rotten in the foliage.

2. WATER

If you’re the proud owner of a Peace Lily (Spathiphyllum wallisii) you’ll know why this one is in line for the key rainforest feature of water. This plant grows in the dense forest undergrowth, so it really isn’t too bothered about getting a lot of light, but it has adapted to dense, damp ground - and that’s what we need to give it too.

Think about the forest stream, winding through and under the undergrowth, and keeping the soil moisture consistent . There’s plenty of rain here in the rainforest, and plenty of plants to drink it up when it falls - and this means they have to be well-adapted. If you put a cactus in this environment, it wouldn’t last two minutes… so that peace lily you think of as dramatic is actually pretty hardcore, able to withstand the onslaught of so much moisture. Whether that’s manifested in your home by using a self-watering pot, or by constant love and attention of the kind that has killed many a cactus, it’s key to think of the environment your thirsty plant grows in to give it the right amount.

3. LIGHT

Different levels of rainforest altitude give the plants different amounts of light. The epiphytes growing way up in the canopy get a lot more light than the creepers on the forest floor - and not least because they are stopping a lot of it from reaching those on the ground!

One plant whose light adaptations I always find totally fascinating is the Prayer Plant . There are a few different types of prayer plant - the popular Calathea (AKA Goeppertia), the less well-known Stromantheand hard-to-pronounce Ctenanthe(the ‘C’ is basically silent). But the one I’m thinking of today is the  Maranta - specifically, the red one (Maranta leuconeura‘Fascinator Tricolor’). This plant will trail a little in your home because it creeps along the ground in its rainforest habitat. At this low altitude of the rainforest, it’s had to make some adjustments to maximise the light it gets…

First off, the reason it’s called a prayer plant: the leaves move depending on the light level, allowing the plant to maximise the light it gets. It also has this deep purple colour on the underside of its leaves, which gets more pronounced when it’s somewhere shady. And this really is the fascinating bit. Because darker colours are more absorbent of light, the dark undersides of these leaves help it pick up as much of the light that hits it as possible, maximising the energy it gets from photosynthesis. But not only that, by absorbing more light, it more fully shades the ground underneath itself - discouraging competition from smaller plants and seedlings that might be trying to grow around it. Clever!

So, how is this relevant in your home? Well, you know that this plant is well-adapted to lower light levels, so you won’t be putting it in a sunny window. And you can keep an eye out for its leaves moving - and if they aren’t moving at all, it may be a sign that your plant isn’t getting enough light. If the undersides of this plant only have a smudge of purple, it can stand lower light than it’s currently in, which is always useful to know. Even for shade-tolerant plants, that light level is key - they’ve adapted so well that they do need it to fit with what they’re used to.

4. TEMPERATURE

Tropical rainforest = warm. Easy, right? Well, not exactly… much like how the light level changes as you travel up and down through the canopy, so too does the temperature - especially at night. Where our prayer plants and peace lilies thrive on the forest floor, they are pretty well insulated by the foliage above them, and get nice, consistent temperatures. But higher up in the forest, closer to the canopy, there’s a bit more ventilation, and it’s in these breezier levels of the forest where the temperature falls overnight.

The plants there can cope with consistent temperature levels, but they have really adapted to thrive with that overnight temperature drop. One of the houseplants this is really key with is the tropical Orchid . In our show garden, you might’ve noticed the striking Zygopetalum Orchids, with their purple and green flowers, growing out of our tree trunks above your head. These Zygo Orchids are one of those species which have really adapted to cope with a nighttime dip in temperature of around 5°C, and if they don’t get this change in temperature it can actually make it more difficult for these, along with many other Orchid species, to flower. So if you want your Orchids to give you stunning blooms, it’s actually quite essential to think about temperature, and just where exactly they make their rainforest homes.

5. NUTRIENTS

Rainforest soil is very different to what you’d get in your garden. It is actually not that nutrient-rich , because the conditions are just right for any plant waste dropped on it to decay very 

quickly. The nutrition in the soil tends to be taken into the plants very quickly, as they like to take it up and use it straight away.

When looking after your rainforest plants, then, you do need to make sure they have plenty of nutrients. In your home, you can give them nutritious soil, but they will appreciate the occasional extra feed to supplement this - we usually recommend every few weeks in spring and summer, and a little less frequently when it’s cooler in autumn and winter. However, it’s also important to know what type of feed to use to get the best out of your plants.

The Flamingo Flower is bright and showy, coming in plenty of colours - for our show garden we chose this vibrant red, and loved the colour it brought in. Flamingo flowers , Anthurium andraeanum, are actually pretty constant flowerers, so they don’t take too many breaks in flowering. They grow onto trees and tree roots, but reasonably close to the forest floor, and to keep those flowers going, they do need the right nutrients straight out of the earth. While you may not have the rainforest leaf litter to hand, it is useful to know that plant feeds high in potassium - such as a tomato feed - are great for encouraging flowers. This will be helpful for giving the right stuff to your flamingo. Conversely, with the plants where the foliage is really the star, a feed with more nitrogen will be best for encouraging those lovely leaves. That’s what most houseplant feeds are designed for, so if you’re feeding your flowers and just keep getting more leaves, it’s probably worth checking the concentrations. The main nutrients are Nitrogen, Phosphorus and Potassium - shortened to NPK, and most fertilisers will show you what the relative concentrations of each are.

So, you might think your plants are chilling in the soil they’re in, but don’t forget to think about the rainforest - that layer of mulch is constantly getting taken up by the plants rooted into it, so your plants may appreciate a feed once in a while to remind them of home.

The Myth of Perfection

Our sixth takeaway was that, despite their - and our - best efforts, plants are not perfect . They aren’t always the storybook-type, insta-ready, perfect-looking houseplants. But that’s not what they look like in the rainforest either - out in the wild, they’ll encounter critters like leafcutter ants who’ll have a nibble, or they might get torn or trodden on by a passing ocelot. Maybe they’ll get climbed over by a sloth, used as a perch for a hummingbird, or batted by a frog’s tongue as it reaches for its next meal. And maybe your houseplants will lose a leaf while you’re on holiday and not watering them, or get a tear from your own furry friends brushing past them. But none of this makes them less appreciated, or makes you a bad plant parent. As long as you do water them when you get back from your holiday…

While we’ve been looking at all of these gorgeous rainforest habitats, we’ve also been bringing new insight to our own indoor jungles. Knowing what the ideal conditions are is helpful, but it’s impossible to perfectly recreate the rainforest indoors . Trust us, we’ve done it as well as we could - and we’re not sure we could have kept it happy for another week, let alone year-round at home! But the other thing we have learnt is that perfect plants are a bit of a myth - at least, in the social-media-ready version we all wish we could recreate. Plants are not perfect in the habitat they have spent millennia adapting to - so why would they be in our homes, so far away from that ideal? And while we may be able to control and anticipate many aspects of the environment in our homes, we can’t predict everything - and we can’t expect ourselves to be perfect, to always water on time, and to never let any accident befall our precious plants. We can just do the best with what we have, and use our plants to de-stress and bring a little bit of the rainforest indoors. See them as a refuge, not another source of stress.

And if you want to get some context for what I’ve been wittering on about, and learn more about our houseplant essentials, and the plants and animals we filled our indoor show garden with, you can pick up our companion booklet in the shop or read it online here.