The crocodile fern is ideal for beginners and green-fingered collectors alike. With this guide, growing your own at home is a piece of cake.
So, if you’re looking to add it to your indoor jungle, here’s everything that you need to know.
What Is a Crocodile Fern?
The crocodile fern (Microsorum musifolium), also known as alligator fern or crocodyllus fern, is a tropical fern. Prized for its unique foliage, the plant is native to the Philippines, Malaysia, Indonesia, New Guinea, and Polynesia. While it naturally grows as an epiphyte, the crocodile plant is also well adapted for container growth.
This fern’s main feature is its leaves. Crocodile fern grows abundant clusters of fronds, which range in size from 5 to 10 inches (13 to 25 cm). The leaves have a lush green color and are covered with a network of dark green veins. The result looks very similar to crocodile scales, hence the name.
In the wild, tropical forests of its native habitat, the crocodile fern will grow up to 4 feet (1.2 meters) tall and wide. However, when grown as an indoor plant, it has a more contained growth habit and rarely grows bigger than 2 feet (60 cm).
Crocodile Fern Care Guide
The crocodile fern is a nontoxic, low-maintenance plant that will make an exotic addition to any home. So let’s start with the indoor care basics for this fern.
– Light Requirements
The crocodile fern is a shade-loving plant. In its native habitat, this fern grows as an epiphyte. That means it uses its roots to get water and nutrients from the trees it lives on.
As a result, it is used to receiving low light and can tolerate dappled shade as well as heavy shade. It is essential that you pick a part of the house that mimics the fern’s natural growing conditions.
Place your crocodile fern in a room with eastern or northern exposure, away from any direct sunlight. This way, the leaves will receive enough light for photosynthesis and maintain their vivid color without being scorched by the sun.
If your bathroom has a window, it will make a perfect room for the crocodile fern, meeting both the humidity and light requirements needed for healthy growth.
– Temperature Requirements
The ideal temperature range for the crocodile fern is between 64 F and 75 F (18 C to 24 C). This is the average temperature found in most houses, so the fern should have no problems feeling comfortable and thriving in your home.
You can grow crocodile fern as an outdoor plant in USDA hardiness zones 10 and 11. If you’re planting it outside, pick a shaded part of the garden. Use trees and shrubs to protect the fern from the intense midday sun.
Crocodile fern is not frost hardy. Temperatures below 50 F (10 C) can permanently damage this plant.
– Water Requirements
Water your crocodile fern regularly and thoroughly. This plant loves moist soils and is very sensitive to drought. Check the soil with your finger and give the plant a good soak when the top inch feels dry to the touch. Allow the water to run through the drainage holes. Give it a few minutes to drain before placing it back on the container dish.
In summer, you can water the crocodile fern twice a week. During the colder months, reduce the watering to once a week. Use room temperature water for this fern as cold water will shock the plant and may cause the leaves to wilt.
Although the crocodile fern thrives in moist soils, it can also suffer from overwatering. Be sure to adjust your watering schedule depending on the season, temperature, and size of the pot. Most of all, never water the plant if the soil feels damp to the touch.
– Humidity Requirements
Humidity is one of the most important factors in growing any fern species. For the crocodile fern, you will need to raise the humidity levels to at least 70 percent. If the air is too dry, the leaves will start to turn brown and crispy, and the plant’s health will suffer.
Meeting the crocodile fern’s high humidity requirements can be a bit of a challenge. Whenever possible, we recommend placing it next to a humidifier in a room that’s not exposed to drafts and sudden temperature changes. You can also try misting the leaves, but you will need to do this twice a day for any noticeable results.
Given that the crocodile fern needs a lot of humidity, it is often recommended that you grow it in a vivarium or terrarium. These enclosed spaces are perfect for retaining air moisture and can reach humidity levels of around 80 to 90 percent, which is the ideal range for this fern.
– Soil Requirements
Crocodile fern needs a soil mix that is nutrient-rich, well-draining, and aerated. Drainage is the most important soil feature for this plant. If you create a well-draining mix, you will avoid problems such as root rot or attracting pests.
You can grow crocodile fern in most universal potting mixes. However, we recommend adding a few amendments to improve drainage and aeration.
Here’s a great soil mix recipe that you can use:
- 1 part universal potting mix
- 1 part perlite or coarse sand
- 1 part peat moss
- 1 part pine bark
Crocodile fern needs moist soils to thrive, yet moist soils can be susceptible to bacteria and fungal problems. Therefore, we recommend adding a handful of horticultural charcoal to the mix. This medium will not only improve drainage but also balances pH levels in the soil. On top of that, it has antifungal and antibacterial properties.
– Fertilizer Requirements
Crocodile fern is a light feeder. It only really needs fertilizer applications in spring and summer. Use a diluted universal fertilizer once every two weeks. A balanced nutrient ratio, such as 10-10-10, is best for this plant.
Cut down on fertilizers from mid-autumn until the end of winter. During the colder months, crocodile fern grows much slower. As a result, it will need fewer nutrients. Feeding the fern in winter will result in a buildup of fertilizer salts in the soil. This can then burn the roots and create a breeding ground for pests and diseases.
– Pruning and Maintenance
Crocodile fern needs minimal maintenance. Every now and then, you will need to remove the older leaves from the bottom. Simply cut them using a pair of gardening scissors.
It’s normal for the older leaves to start turning yellow as the plant matures. Trimming the older leaves will not only create more room for new growth but also improves air circulation around the fronds. This way, you will also reduce the chances of fungal problems developing later on.
Once a week, wipe the leaves of the crocodile fern with a damp cloth. Avoid using any leaf shine products, as they will severely damage the fronds.
– Repotting Crocodile Fern
While Crocodile fern has a fast growth rate, it doesn’t need repotting too often. Like all fern species, it has a shallow root system, and it doesn’t like having its roots disturbed too often. In fact, the crocodile fern enjoys being a bit root-bound.
The easiest way to tell if your fern needs to be repotted is by checking the underside of the pot. If you can see roots poking out through the drainage holes, it’s time to move the crocodile fern to a bigger container.
The best time to repot crocodile fern is in spring or summer during the plant’s growing season. Pick a pot that’s one size larger than the previous one or is two inches wider.
Plastic pots are ideal as they help preserve the moisture in the soil. Always make sure that the new container has adequate drainage holes at the bottom.
Crocodile Fern Propagation Guide
Crocodile fern can be propagated through either plant division or rhizome division. Mature ferns will produce new clusters of fronds, which are easy to separate from the mother plant. However, if your fern is still too young to produce new growth, you can propagate it through rhizome division.
The best time to propagate your crocodile fern is in spring or summer. Let’s take a closer look at how each propagation method works.
– Propagating Crocodile Fern Through Plant Division
- Take the plant out of the pot and remove some of the soil covering the roots.
- Find the spot where the new cluster of leaves attaches to the mother plant.
- Using your fingers, gently pull the young plant away from the mother plant. If the roots are tangled or stubborn, you can use a sharp, sterilized blade to cut some of them. Make sure you don’t cut the main roots, as this can shock the fern.
- Plant the new fern in a well-draining potting mix and give it a good watering.
- Keep the plant in bright indirect light, and give it plenty of humidity. Your new fern should become established in about two weeks.
– Propagating Crocodile Fern Through Rhizome Division
- Start by taking the fern out of the pot and removing some soil to expose the roots.
- Look for the rhizomes: they should grow just below the soil surface and should be thick, slightly woody, with lots of smaller roots growing out of it.
- Find a rhizome that is at least 2 inches (5 cm) in size, with plenty of leaves and roots;
- Use a sharp, sterilized blade to cut the rhizome in half.
- Place the rhizome in a new pot filled with well-draining soil. Don’t plant the rhizome too deeply. Instead, loosely cover it with about 1 inch (2.5 cm) of potting mix.
- Give the new plant a good watering, and make sure it has plenty of humidity. To increase the fern’s chances of becoming established, cover the pot with a transparent plastic sheet for around three to four weeks.
Common Pests and Problems
The crocodile fern has very few pests or diseases that you need to worry about. Keep the plant healthy by providing it with the right growing conditions, and it will give you very little trouble.
However, there are a few things to keep an eye out for, such as:
– Dried, Crispy Leaves
This is the number one sign that your crocodile fern is not receiving enough humidity. Avoid keeping the fern in a dry room, under an air conditioning unit, or close to a radiator. Ideally, the humidity levels should be around 70 percent to prevent the leaves from drying out.
– Root Rot
Overwatering can be a real threat for the crocodile fern, causing fungal problems such as root rot. If you notice that the leaves turn yellow, then soft and brown, take the fern out of the pot and inspect the roots. Trim off any sections that are soft and black, and repot in a well-draining, aerated potting mix.
Crocodile fern can be susceptible to scale. These small, round insects live underneath the fronds, causing leaf discoloration and wilting. Use a cotton bud dipped in a neem oil solution to dislodge them from the leaf. Then, spray the plant with the neem oil solution every five to seven days until all signs of infestation are gone.
Crocodile fern makes a wonderful addition to any indoor jungle! Fairly low-maintenance, it’s a top choice for beginners. Just be sure to remember the basics.
- Crocodile fern is a tropical houseplant that typically grows two feet tall and wide.
- It is a shade-loving plant, making it a perfect choice for the darker areas in your home.
- It needs very high humidity levels for healthy growth.
- This fern can be propagated through plant division or rhizome division.
- Crocodile fern is tolerant to most pests and diseases, yet it can suffer from overwatering, low humidity, and scale.
Now all you need to do is get your hands on your very own crocodile fern!
- Alocasia Cucullata: Parenting the “Fortune-Calling” Buddha Palm Plant - September 20, 2021
- Philodendron Lupinum: Nurturing the Ever-Changing, Climbing Philodendron - September 20, 2021
- Phalaenopsis Violacea: The Gorgeous Tropical Beauty - September 20, 2021