Fern Care

a hand holding a single fern frond

            Ferns are a fantastic plant to add to your collection! They are one of the few houseplants that never flower, nor do they create seeds. Ferns reproduce via spores but differ from mosses due to their vascular structure within the plants themselves. They’re an ancient type of plant that first appear in the fossil record in the late Devonian Period 360 million years ago and have been persisting and diversifying ever since. Some have fairly simple fronds that radiate from a central rosette like that of a bird’s nest fern. Others grow on trees as an epiphyte, such as the staghorn fern. But many take more familiar forms with fronds comprised of small segments like wood ferns. True ferns are all pet safe, though beware of fern imposters if you are searching for pet safe plants exclusively. The asparagus fern is not a fern and is toxic to children and pets. Luckily for houseplant, many of the ferns have very similar care to each other.


            Think of the environment the ferns naturally live in when considering where to place your fern. They grow in the understory in shady areas, and sometimes even in deep shade in well established forests. While bright indirect light is appreciated by many ferns and will help them to grow more quickly and resist potential problems, direct light will burn their leaves. Ferns are tolerant of many low light situations and tend to thrive in more humid environments, making them perfect for the bathroom, where not many plants can thrive. Even though they tolerate low light levels, it is still possible to provide too little light. If your fern halted growth and is in a dim area, this is possibly the cause.

A fern growing in the crack between a rock


            Ferns need consistent moisture. Always check the soil before you water to avoid root rot. When the soil is dry about an inch down, it is time to water again. When you water, the soil should be completely saturated. This may sound like over watering, but over watering is the frequency, not the quantity of water. Watering small amounts more often will not allow the soil to dry properly, which leads to the roots being constantly soaked, which impairs gas exchange within the roots and will lead to the suffocation and death of the roots. Instead, completely saturating the soil and waiting until it reaches the correct level of dryness before repeating the process ensures the plants have plenty of water to drink and the roots will not rot. This applies to everything from ferns to succulents! No matter if you are watering from the top or the bottom, the soil should be completely saturated. If watering from the top, this looks like adding water until the excess drains from the holes in the bottom of the pot. If watering from the bottom, be sure to add enough water to the tray the pot is soaking in to saturate the entirety of the soil. This may mean going back later to add more water halfway through the process. Allow the plant to soak until the top of the soil is moist. This could take minutes or hours depending on the pot size.


            Ferns grow in soils with high organic content; the “dirt” portion of potting soil. Ferns will thrive in regular potting mix you get from garden centers without additional amendments. It is important to remember to fertilize ferns regularly. Because they live in areas with lots of natural compost, they tend to be one of the more hungry houseplants out there. How often it is appropriate to fertilize depends on what type of fertilizer you use. Liquid fertilizers should be applied more often than slow released fertilizing pellets. No matter what fertilizer you choose to use, be sure to follow the directions on the bottle.


Common Problems

            Ferns, like many popular houseplants, are fairly disease resistant, but unfortunately that doesn’t mean they never have issues. Many of their most common problems are due to different environmental factors. Listed below are a few of the most common problems you may be experiencing with your fern and how to fix them.

Crisping Fronds

            Crisping fronds unfortunately can be caused by more than one factor. The good news is that they are both easy to fix! If the crispy portions of the leaves are dull in color and focused on the new growth, this is a sign of underwatering. This is easily fixed by following the watering directions above. If the edges of the fronds are crisping and turning brown, this is a sign of too low humidity. Moving the fern to a more humid room such as the kitchen or bathroom will help, but some houses are drier than others and may require the addition of a humidifier. Moving the fern to a greenhouse cabinet will also help to increase the surrounding humidity.

a hand holding a birds nest fern without a pot. healthy roots can be seen

Root Rot

            Root rot is unfortunately one of the more common issues with ferns. Symptoms of root rot include mottled yellowing of the leaves, stunted or halted growth, severe wilting, and the loss of fronds. If your fern has many segments to its fronds, the segments may begin to fall off individually. Check the roots to determine whether your suspicions of root rot are correct. Healthy fern roots are thin and brown, which can be confusing because other plants’ roots can look similar to healthy fern roots when experiencing root rot. The photo to the left shows healthy roots. Carefully compare the roots to one another. Trim off any unhealthy roots and reduce the frequency of watering. If the problem persists, a fungicide may be beneficial.

Yellowing of Central Leaves

            This occurs more often in birds nest ferns and other species that grow in the rosette pattern than in ferns that grow with numerous fronds in several different directions. Often, this is caused by watering the foliage of the plant when watering from above. This is easily fixed by watering just the soil with a watering can or hose attachment, or by watering from the bottom. Keeping your fern in a dark location is likely to make this problem more prolific.

Fronds Rotting from the Base

            Collapsing fronds that often have yellow portions unfortunately often spells doom for ferns. This is typically due to extensive rot that has spread to the crown of the plant, which resides just below the soil. Ferns can survive this, but it is best to prevent it before it happens. The most common causes of this pattern of rot include excess moisture between watering, a pot without drainage holes, water sitting below the pot often in a cover pot, and too little light. Sometimes extensive root rot will become crown rot, though this is not always the case. Ferns will often show other symptoms of distress before it comes to this.

            Having a collection of only ferns would still be stunning to the eye due to the extremely varied appearances of many of them. Pet owners and parents can rest easy with the non-toxic nature of this group of plants. As always, if you have any questions or concerns about your plants, please do not hesitate to reach out. Send a photo as well as how you have been caring for your plant to cedarbridgebotanicals@gmail.com and I will be able to help you!

Happy Growing!

<3 Gina

many fronds viewed from above