Ferns in the terrarium
Terrariums have an important history in that Wardian Cases, the first, sealed containers used to transport plants around the world, were self-sustaining wood and glass terrariums. Nowadays, they are usually miniature gardens housed inside small, sealable glass containers and are designed for interest and decoration. As fully functioning plant ecosystems, the plants water themselves through transpiration and condensation.
1
Location
As terrariums are self-contained, they can be positioned attractively anywhere in the home. An electricity supply is needed for lighting, and they should not be placed in direct sunlight, which will raise the temperature of the terrarium. Access must be easy for regular maintenance.
2
Watering
If the terrariums is fully sealed, additional watering should not be necessary after set-up. However, the initial watering should be with clean, ideally sterile, deionised water or rainwater. Top-up watering may only be needed to account for leaks and water removed during maintenance.
3
Substrate
Attractive displays can be created that show ferns to best advantage. Rocks, wood and bark should be clean and free from pests, weeds and fungi. Compost should be sterile and free from earthworms. Drainage is important so that the compost does not become sodden and sour.
Choice Ferns
Here is our selection of ferns that do well in the terrarium. They are often available from specialist websites. Many other small exotic ferns will also thrive in these ideal conditions but might be harder to come by. Many of these ferns will climb or scramble over the hardscape materials and help you create a miniature little world.
Creeping Button Fern
Pyrrosia nummulariifolia
An easy to grow little fern with small, soft leathery fronds. It will happily creep around the terrarium and climb over hardscape materials.
Cotton Candy Fern
Nephrolepis exaltata 'Marisa'
A diminutive and fine form of the Boston Fern that is very happy in the terrarium. It can form large clumps and will need to be divided regularly.
Krauss's Clubmoss
Selaginella kraussiana
This is a versatile plant that is happy in many environments—it will even sometimes survive mild winters in the garden. It will spread quite quickly and form a lush carpet.
Vine Fern
Several small Microgramma species are available and most are suitable for terrariums. Once they get going they climb and attach themselves to rough surfaces.
Antenna Fern
Pellaeopsis pilosa
Previously sold as a Doryopteris species, these are attractive small plants that produce young plantlets on the surface of the ivy-shaped frond. They like high humidity and will grow well in a terrarium, so long as they don’t fall prey to aphids.
Heart Fern
Parahemionitis arifolia
Until recently, this fern was known as Hemionitis arifolia. Like Doryopteris, it reproduces by both spores and by plantlets that form at the join of the stalk and frond. It is easy to grow new plants from these but care must be taken to avoid rot.
Caring for your ferns in your terrarium.
Terrariums can provide a suitable environment for ferns that need high humidity. There are two types of terrariums—open or closed. Open terrariums will have an opening to the room in which they are placed. Whereas closed terrariums are sealed with a lid or door. Closed terrariums are generally more suitable for ferns that appreciate high humidity conditions, particularly for a specialist group of ferns, known as 'filmy ferns'. Being self-contained, the humidity is constant without needing much intervention.
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An attractive display can be created by using wood and rocks to mimic a natural environment. These substrates can be useful for growing small epiphytic ferns. On the base of the terrarium, a bark and compost mix can be used to plant terrestrial ferns. If this base substrate layer rots too quickly, you may need to strip down the display and start again. So, if you plan on using a misting system or if frequent watering is needed, it might be useful to put additional drainage under this mix. Pea gravel or clay balls can be used, and plastic mesh placed on top to prevent the main substrate mixing into this drainage layer.
There is an impression that terrariums are low maintenance. This always isn’t true, particularly if you are trying to maintain specific ferns or a special collection. If the ferns are growing well, some may grow too big or too numerous for the space. One species can rapidly smother other species. Also, if the plants are overcrowded, fungal diseases and pests can take hold and be difficult to remedy in such a small environment. It is very important to be vigilant and to keep on top of maintenance tasks. Remove dead or dying fronds, unwanted moss and algae, and take out ferns that are too large or propagating too quickly.
Collections
Developing and maintaing a fern collection. How to safeguard your collection for the future.