How to Grow Maidenhair Fern Indoors

Adiantum Fern

The Spruce / Anastasiia Tretiak

Maidenhair Fern is part of the Adiantum genus that includes over 200 varieties of ferns grown around the world. The genus name is derived from the Greek word adiantos, which means "unwetted"—an apt description for the fern, since its leaves repel water. Maidenhair ferns have delicate fan-shaped leaf segments, typically clustered on wiry black stems. In addition to being a popular houseplant, maidenhair fern can also be found in nature, growing in places where other plants typically don't, like on rock walls and in between rock fissures where the moisture from water seepage keeps them alive. Though the are visually stunning throughout all stages of their growth, they are considered a slow-growing fern, typically taking up to three years to reach their full mature size.

Botanical name Adiantum raddianum
Common name Maidenhair fern, Delta maidenhair fern
Plant type Fern
Mature size 1–2 ft. tall, 1–2 ft. wide
Sun exposure Partial sun, shade
Soil type Moist but well-drained
Soil pH Neutral
Bloom time Non-flowering
Flower color None
Hardiness zones 10, 11 (USDA)
Native area North America
Toxicity Non-toxic
closeup of maidenhair fern
The Spruce / Anastasiia Tretiak
overhead angle of a maidenhair fern
The Spruce / Anastasiia Tretiak
closeup of maidenhair fern
The Spruce / Anastasiia Tretiak

Maidenhair Fern Care

Maidenhair ferns are delicate plants with very small fronds and a lace-like appearance. They're considered hardy ferns, rather than tropical ferns, but don't let the description fool you: maidenhair ferns can be difficult to keep healthy indoors, as they're quite particular about their growing conditions. The most important environmental factor when it comes to growing this fern with success is humidity—it thrives on moisture and needs a lot to survive, which can often be difficult to achieve in indoor environments. Still, with the proper growing conditions, maidenhair ferns can be an interesting and beautiful addition to any indoor plant collection.  

Light

In their natural forest environment, maidenhair ferns are primarily covered by a canopy of trees, receiving a bit of shade and a bit of partial sunlight. To successfully grow the fern indoors, it's best to try and mimic these conditions by finding a spot in your home that receives indirect sunlight only. Avoid harsh light or direct rays, as the delicate leaves of the maidenhair fern can burn very easily.

Soil

Maidenhair ferns prefer moist but well-draining potting soil. As mentioned, water is very important to this fern, so up your chances of creating the proper environment for it by incorporating moss or an organic matter like compost into the soil to help it to retain water.

Water

Your best bet when it comes to ensuring your maidenhair fern thrives is to focus on multiple water sources for this thirsty species. Consistently moist soil is a great place to start—from there, be sure to water your fern consistently, either daily or every other day, never allowing the soil to dry out. Keep the fern in a plastic pot with holes, then place the plastic pot in a more attractive outer pot if you wish. This way, you can easily check on the moisture levels in the plastic pot, and the drainage holes will prevent the soil from becoming too soggy.

Temperature and Humidity

This fern requires very warm, humid air. To mimic its ideal conditions, mist the plant with warm water a couple of times a day in order to maintain the proper moisture levels on its delicate leaves. Alternatively, you can place the potted plant near a humidifier or atop a tray of wet pebbles to increase moisture levels. Also consider housing the plant in a moisture-rich environment at home, such as a bathroom or garden greenhouse. If you notice the fern's leaves are curling up, the leaf tips are dry, or the leaves are falling off frequently, it's likely that the air is too dry and the plant needs more moisture and humidity. Temperature-wise, the fern is best kept above 70 degrees Fahrenheit and should not be placed anywhere in your home where the temperature or cold drafts dip below 60 degrees Fahrenheit.

Fertilizer

It's not necessary to fertilize a maidenhair fern, as the plant will do just fine without it. However, if you wish to provide it with an added dose of nutrients, feed with a balanced, diluted blend once a month, avoiding any feed with too much nitrogen (200 ppm or less), which can cause the tips of the leaves to burn. Additionally, regular trimming and the removal of browned leaves can also help the fern grow denser foliage.

Repotting Maidenhair Ferns

These ferns can be repotted annually or biannually, depending on the pot size and the plant's growth rate—they don't mind being a little crowded, so don't rush to repot them if you're unsure. Instead, wait for signs that your fern is outgrowing its home, like the roots filling up the pot. To repot a maidenhair fern successfully:

  • Use a knife or spade to divide the roots.
  • Divvy the plant up into more manageable sections, maintaining a minimum of two to three healthy fronds within each division.
  • Plant each section into its own pot, and be sure to water them well.
  • Do not fertilize the repotted ferns right away, as this may burn the roots.