How to Grow Maidenhair Fern (Adiantum)

By Matt Gibson

Though Maidenhair Ferns are popular houseplants, they have gotten a bad reputation amongst gardeners for being very particular, difficult to please plants that need a high humidity environment at all times to perform well. While maidenhair ferns do require some specific care to thrive, they are not as tough to please as their warning label suggests.

One thing is essential in caring for maidenhair ferns, and that is keeping the soil fully and evenly moist at all times. The second the top layer of soil feels slightly dry, it’s time to water again. If the potting soil in the container holding your fern goes so much as halfway dry, all of the fronds on your fern will turn brown and crumbly overnight.

Fortunately, this drastic downfall is not a death sentence for your fern, but saving it at this point is going to require intensive care. You will need to cut back all of the brown fronds, reinvigorate the soil with a proper soaking, and put the container in a spot that gets a full blanket of bright, indirect light.

If this approach is able to encourage a few new fronds to sprout up, you have a chance to get your fern back to its former glory. Continue to provide the needed amounts of water and indirect light exposure for the next few months and you won’t be able to notice that your fern was once knocking on heaven’s door.

So, in short, Maidenhair ferns are not impossible to please, they just need consistency and attention. Direct sunlight exposure is welcomed as well, but you will need to pay closer attention to the soil moisture levels when your fern is sunbathing, as the soil can dry out much quicker in direct light.

Maidenhair Fern belongs to the Adiantum genus which consists of over 200 ferns from all over the world. The fern’s delicate, fan-like leaf segments repel water. Leaves grow in clusters on wiry black stems. Despite their demanding nature, maidenhair ferns are a very popular houseplant.

They are also found in the wild, growing naturally in places where most plants never tend to grow, such as between rock fissures, where they can drink from the moisture provided by water seepage when necessary, or on rock walls, where establishing a hold with roots is tough for most plants. Maidenhair ferns are slow-growing ornamentals, which can take upwards of three years to reach full maturity.

Growing Conditions for Maidenhair Fern

Place your maidenhair fern in a location that gets a little bit of shade and a little bit of indirect light. Avoid harsh light or direct rays, as they can burn your fern’s sensitive leaves. Maidenhair ferns will grow best underneath the canopy of trees or other large plants that allow only dappled or filtered sunlight to reach your fern.

Maidenhair ferns appreciate constantly and evenly moist soil. Amending your potting soil with moss or well-rotted compost will help with water retention without allowing your soil to become soggy in the process. Ideally, your fern should be kept in temperatures above 70 degrees F and should be protected against cold winds and temperature drops that dip beneath 60 degrees F.

How to Plant Maidenhair Fern

Maidenhair ferns are typically purchased as young plants in a small plastic pot. When you get your maidenhair fern home, you will want to plant it into a larger plastic pot with drainage holes, or, if it still has plenty of room to grow into it, keep it in the plastic container that it is already in and place that container into a more decorative outer pot, as long as the outer pot has a nice-sized drainage hole. Don’t use clay pots for maidenhair ferns, however, as the soil inside clay pots tends to dry out more quickly than other containers. When the soil dries out, maidenhair fronds will start to shrivel up and die pretty quickly.

Maidenhair ferns need to be repotted whenever they become root-bound. Once your fern is root-bound, wait until spring, and repot into a larger container using a rich, high-quality potting soil that contains lots of organic matter, such as well-rotted compost.

Care for Maidenhair Fern

Never allow the soil to dry out. In the absence of rain, water daily or every other day. Ideally, maidenhair ferns should be kept in a location that is very warm and humid. Mist your fern with warm water several times per day or keep the container near a humidifier or sitting on a tray of wet gravel or pebbles.

Keeping your maidenhair fern in the bathroom so that it is exposed to humid conditions regularly is another great way to get the humidity that it loves. If you have a greenhouse, your fern will enjoy the warmth and humidity created there as well. If you see your fern’s leaves curling up or getting dry tips, or catch leaves falling off regularly, it’s probably because the air is too dry and you need to increase the irrigation and humidity levels.

Maidenhair ferns do not require fertilization, but providing an extra boost by adding nutrients will help your fern grow more voraciously. Apply a diluted balanced fertilizer that is low in nitrogen once per month. Feeds with excessive amounts of nitrogen can burn the plant’s leaf tips. Pruning and trimming back brown leaves and spent fronds will also help to promote new foliar growth.

How to Propagate Maidenhair Fern

There are two ways to propagate maidenhair fern plants: with division or by using their spores. Unless you’ve propagated ferns before, spore propagation may be unfamiliar, and division is incredibly easy.

Your maidenhair fern must be well established before you can successfully divide it. Use your hands or clean, sterilized garden shears to separate the fern’s root ball into two halves. Then plant the two sections in separate containers and begin caring for them as two separate plants. Don’t be alarmed if you notice some foliage die off before the newly divided ferns get settled.

Because maidenhair fern plants do not produce flowers or seeds, the spores are how the plant reproduces on its own. When your fern creates spores, you will notice the brown dots appearing at the tips of leaves on the back side. Use clean, sterile shears to trim off a few pieces of foliage, then place these cuttings between two sheets of paper and put them away for a week. When the week is up, the dots (which are the fern’s spores) will have separated from the leaves, and you’ll find them resting on the paper.

Place the spores on the surface of the soil in a container filled with fresh potting mix. Then use plastic wrap to cover the container, simulating a greenhouse environment. Find a warm, safe location for the container that is out of direct sun, which can get too hot for the little spores. Use a spray bottle to keep the soil in the container consistently hydrated, and you can watch the plants progress from spores through the gametophyte stage, eventually maturing into their sporophyte form—the fern plant you’re familiar with.

Garden Pests and Diseases of Maidenhair Fern

Maidenhair ferns are susceptible to many of the same insect and disease threats that can be an issue when you’re cultivating ferns of any kind. However, if you take a few preventive measures and inspect your fern on a regular basis so problems are noticed quickly (and therefore handled quickly), these issues are manageable. Below we’ve listed the most common pests and plant diseases that gardeners of maidenhair ferns should be familiar with.

If you have an outdoor garden, you’re bound to deal with slugs and snails. They feed at night, chewing holes in plant leaves or bulldozing seedlings completely, leaving silvery slime trails where they’re been. If you see a slug or snail in the garden, remove it and drop it in a bucket of soapy water. You can encircle vulnerable plants with diatomaceous earth (DE), which hurts the mollusks’ fragile bodies, so they won’t cross it. DE is also effective for deterring caterpillars. If a tougher defense is needed, our article How to Protect Seedlings from Slugs and Snails will tell you how to make an electrified barrier using copper tape and give other options for keeping slugs and snails off your plants.

Other insects that can infest maidenhair fern plants include aphids, mealy bugs, scale, and spider mites. Mealy bugs look like bits of white cotton, scale resembles bumps on plant stems, and both aphids and spider mites hang out on the undersides of foliage. All these insects will feed on your plants, leaving the foliage curled, withered, or distorted.

Wiping the plants down with a cotton ball doused in rubbing alcohol is effective against most of these insects. If you need stronger stuff, consider treating with horticultural oils. You can follow the link for each type of insect to get more information about spotting them in the garden, strategies for preventing infestation, and more ways to fight these bugs off if they colonize your plants.

The most common plant illnesses that afflict maidenhair ferns are powdery mildew, rot, and fungal diseases. You’ll be able to spot fuzzy or powdery evidence of fungal disease or powdery mildew if they strike, while rot tends to affect the roots of plants, making them soft and slimy and darkening their color, while the plant above ground eventually starts to wilt or exhibit stunted growth.

All these diseases are most often due to excess moisture, so you can prevent them from happening in your garden by doing what you can to keep things on the drier side. Resist the urge to overwater plants, make sure their containers have drainage holes and the soil provides good drainage, and always water plants at the base instead of from above. You can also take measures to improve air circulation around your plants and refrain from working in the garden if it’s wet due to recent watering, rainfall, or morning dew.

Maidenhair ferns are lovely house plants that require a bit of extra attention. If you can keep their soil evenly moist but never soggy and provide a warm, humid environment with lots of indirect light, you will have lots of success keeping your maidenhair ferns content and well-nourished. Their tough-to-grow reputation is easy to overcome if you know how to keep them happy.