Fabulous ferns have been popular houseplants since Victorian times – almost two centuries! While other fads come and go, the love of ferns in the plant community doesn’t look like slowing down any time soon.
These ancient plants have been around since before the dinosaurs. While they don’t flower, they can bring a flourishing, tropical feel to a space that few other plants can.
But how do you go about growing ferns in pots? And why do people say killing them is easier than caring for them?
I thought I’d put together a guide to keeping indoor ferns alive (and happy) so they bring you joy for years to come. If you’d like to try growing ferns in pots indoors, here’s how to treat them.
Potted ferns and light
There’s a common misconception that has spread around about ferns for decades. The theory is that indoor ferns prefer low light settings.
Unfortunately, that piece of mis-advice has probably killed more ferns than are alive in homes today!
It’s true that in nature, most members of the fern family live on dimly lit forest floors. From the very beginning, they grew under the cover of jungle or forest trees.
However, when you’re growing ferns in pots indoors, they prefer bright indirect light.
If a potted fern doesn’t receive enough light, it will be unable to properly photosynthesize and produce enough energy for itself.
Each species of fern will have its own preferences, but the vast majority of these plants will be happiest in brighter locations, as long as the light isn’t intense and direct.
The fronds of ferns are quite gentle, so they are very prone to sunburn even with minimal exposure. Make sure to keep them near a window but not in full view of direct sunlight.
Keep things simple – choose one of the easiest fern varieties to grow indoors.
Best soil and fertilizer for potted ferns
The roots of a fern are often just as delicate as their leaves appear to be above the soil.
These plants are used to the light soil of the forest floor, so they like light, easily aerated, and well-draining soil mixtures so their roots don’t have to work to break through dense soil to grow.
Ferns enjoy mixes of any good-quality potting substrate that also includes perlite, peat moss, or coco coir mixed in to help extra oxygen get into the roots of the plant.
Luckily, ferns are not picky when it comes to fertilizer, and are known to appreciate almost any organic additives.
During the growing season, it’s a great idea to fertilize your fern once or twice each month. You can use a natural substance like worm tea, compost, or a slow-release fertilizing product.
Even homemade fertilizers made from eggshells or banana peels will be absorbed and appreciated by ferns!
Water and humidity – the top fern concern
Moisture is the hot topic when it comes to fern care. While the exact requirements will depend on the species of fern, these plants absolutely love high levels of moisture and humidity.
In fact, this is so important to the life of a fern, that the most common reason for death among ferns is underwatering and low humidity.
The surest way to keep pot-grown ferns alive is to ensure that their soil rarely gets dry and that the humidity in their area stays nice and high. Follow these easy steps to keep your ferns moist:
1) Check the soil often to see if they need water.
Keep in mind that you want to keep your ferns’ soil damp, but never soggy. (If you have a busy schedule, you can always use water stakes or self-watering planters.)
2) Increase the humidity of the room with a humidifier.
This will allow you precise control over the humidity in the air. If you would prefer the more affordable route, you can always sit your ferns on a pebble tray instead.
Temperature – how cool is too cool for an indoor fern?
Where a fern is originally from and how it has evolved to survive will affect the temperature range it can survive at, but most ferns are relatively temperate plants that thrive best at 60°-80°F (15°-26°C).
These plants don’t love the cold because of their thin, tender leaves that aren’t built to be hardy. They also don’t enjoy extreme heat because it causes their soil to dry out much quicker.
With this in mind, it’s a great idea to keep your fern far from direct exposure to draughts and heating/cooling vents.
The air circulation these two things provide is appreciated by ferns, but not when very hot or very cold air is blowing directly onto the plant and its fronds.
Best pots for indoor ferns
Despite their showy fronds, the root structures of ferns are naturally shallow. So when growing ferns in pots, you don’t need anything particularly large or special.
Containers made of any material, including terracotta and plastic, are suitable for ferns. That said, they will need a different watering schedule depending on the type of material.
Ferns in terracotta pots, known for absorbing excess moisture, will need watering more often than ferns in plastic containers.
With the short roots of the fern family, shallower containers offer the best moisture distribution while still providing enough space for them to grow.
Once the time comes to repot your fern (if you choose not to divide or propagate), go up in pot size by one or two inches. That should keep you set for another couple of years.
Care and maintenance
While I’ve already touched on the most common problem ferns face (underwatering/low humidity), ferns can also experience pest infestations.
Although this is less common in ferns than other plants, it can still be devastating. If left unchecked, pests may even kill the plant if not caught early on.
As you would with all other plants, check the leaves and stems each time you water for signs of pests. Look for strange discolouration, webs from spider mites, or small bug clusters along the veining of leaves, and treat them as soon as you spot them.
I love that sense of wildness ferns can bring indoors. It’s especially appreciated at times like these when many of us can’t get out into nature as much as we’d like. If you’re already growing ferns in pots or are thinking about getting some, I hope this guide helps your green companions thrive!