What is a fern and what are its characteristics?

The plant we call a fern is one of the most primitive plants that exist today, so much so that they shared territory with one of the most powerful animals the Earth has ever seen: dinosaurs. Luckily for us, these reptiles disappeared millions of years ago, but thanks to the adaptability of our protagonist, today we can enjoy their beauty in the garden, terrace and even in some cases inside the house providing the necessary care.

As if that were not enough, there is a wide variety of fern plants: some are small, however, others take on a tree shape. In addition, their beauty is such that it is enough to put them in a corner, or scattered around the area for it to acquire a certain tropical touch.

What is the origin of the fern?

Ferns are shade plants

The fern as we know it today began its evolution more than 300 million years ago , during the Carboniferous period. During that time, the continents were already beginning to separate thanks to the movement of the tectonic plates, so much so that those to the north and those to the south were well differentiated. They were all united by one point; however, those in the north were given the name Laurasia and those in the south Gondwana. Well, our protagonist originated in the south, in Gondwana.

Life on Earth began to proliferate, and the weather conditions were excellent. Warm temperatures, no frost in most of the area . The first sharks began to appear in the sea, which were found with the corals, which already existed at that time.

And as regards the land surface, if we had been there we would have seen the primitive trees, the first reptiles, and of course the first forests that would end up being colonized mostly by fern plants.

What is a fern and what are its characteristics?

The fern is a vascular plant, that is, it has a root, stem and leaves that we call fronds or fronds and inside a series of vessels or conduits through which the sap circulates. Its root system fulfills the function of absorbing nutrients and soil moisture, which are transported by the stem through the xylem that is inside it to the leaves. In addition, the nutrients obtained in the leaves during photosynthesis are carried through the phloem to the roots.

It usually lives in tropical and subtropical regions, under the shade of trees and other larger plants, and in areas where humidity is high. There are some species that resist weak frosts, such as the Balantium antarcticum that holds up well to -4ºC, but most are very sensitive to low temperatures.

What are its parts?

The fronds are the leaves of the ferns

The parts of the fern plant are as follows:

  • Fronds or leaves : they are in charge of photosynthesis.
  • Soros : are the structures found on the underside of the leaves, and thanks to which ferns can multiply by spores.
    In them we find the sporangia, which are the producers of spores. These are the equivalent of seeds.
  • Rachis : it is from where the fronds sprout.
  • Stem : it can be creeping, grow straight or a little below ground (underground).
  • Rhizomes : are the underground stems.
  • Roots : sprout from the rhizome. They are small and superficial, and are responsible for absorbing the nutrients so that they are carried to the leaves, from where the elaborated sap that will feed the rest of the plant will be produced.
  • Conductive vessels : they are found inside each of the parts of the fern. The food that is distributed by the plant circulates through them.

What types of fern are there?

There are many types of ferns, although at first they may all seem the same. But roughly, they could be classified according to their size:

Small ferns, type kills

They are the most popular both in gardens and inside homes, and with good reason: their fronds (leaves) although they are usually long, the root system is not invasive. In fact, they are plants that do not need much space to grow. They can reach a height of 40, maybe 70 centimeters, but if you want to have them in a pot you can rest easy because they live well in containers.

Here you have a selection:

Common fern

View of the Pteridium aquilinum

Image – Wikimedia / Zeynel Cebeci

The common fern , also called the eagle fern, is a plant whose scientific name is Pteridium aquilinum . Its fronds or leaves are green, tri or quad-pinnate, and with a length of up to 2 meters.

It is a very interesting plant for pots and gardens, always in places protected from the sun.

Java fern

Microsorium pteropus is the scientific name of the Java fern

The Java fern is a water fern whose scientific name is Microsorum pteropus . It grows to a height of 35 centimeters , and develops simple, greenish, lanceolate leaves.

It is widely used in warm water aquariums, with temperatures between 18 and 30ºC and a pH between 5 and 8.

Sword fern

The sword fern is a common plant

Image – Wikimedia / Mokkie

The sword fern, whose scientific name is Nephrolepis exaltata , is a plant that reaches a height of 40-45 centimeters in height. Its leaves are green, and very, very numerous. It is widely grown indoors, although it also looks great in a sheltered spot in the garden.

It needs shade, and a mild climate to live. In a sheltered area, indoors and / or surrounded by plants, it can resist cold and weak frosts down to -2ºC.

Male fern

View of Dryopteris affinis

Image – Wikimedia / CT Johansson

The male fern , whose scientific name is Dryopteris affinis , is a plant that produces fronds (leaves) up to a meter long . These are greenish in color, and have a more robust appearance than the female fern known by the scientific or botanical name Athyrium filix-femina .

It is widely grown in gardens, although it is also great in a pot to decorate the patio or terrace. You need protection from the sun and moderate watering.

Sumatra fern

The Sumatran fern is a pretty plant

Image – Flickr / Cerlin Ng

The Sumatran fern is a plant whose scientific name is Ceratopteris thalictroides . It grows to a maximum length of 100 centimeters , and its leaves are green.

It can be had both in aquariums with slightly acidic or alkaline water (pH between 5 and 9), or in pots or in the garden receiving very frequent waterings.

Large or arboreal ferns

They are those that acquire a main stem, wrongly called a trunk, since it is actually an upright rhizome known as a stipe. They can reach heights of more than 1 meter, but as with small ferns, these can also be grown in pots. Obviously, these containers should be larger than if they were used to plant small plants, but apart from taking this into account, surely it will not be difficult for you to get a spectacular garden or terrace.

Here you have a selection:

Australian fern tree

View of the Cyathea cooperi

Image – Wikimedia / Amanda Grobe

The Australian fern tree , whose scientific name is Cyathea cooperi , is a tree fern that reaches a height of up to 15 meters , with a 30cm trunk. Its fronds or leaves are green and can measure between 4 and 6 meters in length.

It is grown in pots and gardens, in exposures protected from direct sun, and watering it frequently.


View of the Blechnum gibbum

Image – Wikimedia / Krzysztof Ziarnek, Kenraiz

The blecno, whose scientific name is Blechnum gibbum , is an arboreal plant that reaches a height of up to 1 meter and a trunk of up to 20cm. Its fronds are long, up to 3 and 4 meters.

It grows in fertile and humid soils (but not excessively), always protected from the sun.


View of the Dicksonia antarctica

image – Flickr / Jungle Garden

The dicksonia , whose current scientific name is Dicksonia Antarctica although still known as antarctica Dicksonia is a fern that can reach a height of 15 meters . Its fronds or leaves are between 2 and 6 meters long, and its trunk remains thin, with a thickness of about 35 cm.

It is a fern in high demand in gardens with a temperate climate, where it is grown in semi-shaded and humid areas.

Rough tree fern

View of the Cyathea australis

Image – Flickr / Pete The Poet

The rough tree fern, whose scientific name is Cyathea australis , is a plant that can reach a height of up to 20 meters , with a trunk thickness of about 30cm. The fronds are long, 4 to 6 meters, the upper surface is dark green and the underside is paler.

It is grown in gardens and pots, with soils or substrates rich in organic matter and well drained.

What are the care of ferns?

Ferns are plants that need a mild climate, shade and high humidity. For this reason, they are not found in deserts or savannas, but for this reason they are also interesting to grow indoors. So if you want to know how the fern plant is cared for, then we will explain it to you:


  • Indoors : the fern can be kept in a room where there is light, away from drafts. Although it is a shade plant, inside the house it is very important that there is a lot of clarity where it is going to be, since if it were kept in a dark room it would not survive.
  • Exterior : if it is to be kept outside, then it is necessary to find a corner protected from the sun, since if it were directly exposed to the sun, it would burn.

Soil or substrate

  • Garden : the soil in the garden must be rich in organic matter, loose and well drained so that the roots do not get puddled.
  • Pot : if it is grown in one, it must be planted with a substrate that is light and rich. For example, it is highly recommended to mix 60% mulch with 30% perlite and 10% worm castings. Thus, it will grow smoothly.

Irrigation and humidity

The fern is a primitive plant

When it comes to watering the fern plant, it must be borne in mind that it does not support drought but neither does excess water on the ground. For this reason, it must be watered from time to time, allowing the substrate to dry out a little – never completely – before rehydrating it. If in doubt, keep in mind that in summer it is usually watered about 2 or 3 times a week, while in colder or cooler times it is watered less, and rainwater or lime-free water should always be used.

If we talk about humidity, if you live in an area where the environment is dry or you have it indoors, you should spray or spray it with water once a day in spring and summer. The rest of the year I do not recommend it, since as the plant hardly grows there is a greater risk of infection.

Anyway, you should know that other things can be done to increase the humidity. For example: put containers with water around the fern, or put other plants or a humidifier near it.


Since it needs nutrients, it must be fertilized while it is growing . Therefore, we can use fertilizers such as one for green plants, or natural fertilizers such as guano, manure or mulch.

Of course, follow the instructions for use so that no problems arise. And it is that if more doses are added than necessary, the fern would suffer irreversible damage, such as the death of the roots.


The transplant is done in spring . To know if our fern needs more space, we will have to look at the following:

  • Roots grow out of the holes in the pot.
  • Roots may not grow out, but the plant can be seen to have taken up all the available space.
  • He has been in it for more than two years.
  • No growth has been seen for a long time (months).

If any of these cases occurs, or several, then we will have to transplant it to a larger pot or, if we want and the climate is right for it, to the garden.

How to prune ferns?

Ferns are green plants

Pruning ferns only consists of removing dry leaves , as well as those that are diseased. This can be done throughout the year, although it is better to do it in spring. We will use previously disinfected domestic scissors.

Fern pests

There are a number of common pests on these plants, and they are mealybugs, thrips, aphids, and leaf nematodes . All of them feed on the sap of the leaves, but luckily they can be removed either with soap and water, or with diatomaceous earth .


The diseases they can have are anthracnose, botrytis and Pythium . All three are caused by fungi, which cause brown or gray spots of different sizes and shapes to appear on their leaves. You can treat them with fungicides.


There are many types of ferns that live in different parts of the world. Therefore, its hardiness varies from one species to another. In general, they are plants that do not resist frost , and must be in areas where the climate is mild all year round.

Now, there are some that do support frost, such as these:

  • Cyrtomium falcatum : it is a small fern, about 40 centimeters, that supports weak frosts down to -4ºC.
  • Deparia japonica : a beautiful deciduous fern that resists up to -20ºC.
  • Pteris cretica ‘Eco Hardy Giant’: it is a fern that supports up to -4ºC.

What did you think of the ferns? Do you have any?

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