Long, undivided evergreen fronds, each shaped like the tongue of a male deer and ribbed underneath with spore lines that look like small millipedes: hart’s tongue fern (Asplenium scolopendrium) reaches 16 to 20 inches and lights up dark corners indoors and out. Give it shade and sharp drainage, and it thrives where little else will.
| Name | Asplenium scolopendrium |
|---|---|
| Formerly | Phyllitis scolopendrium |
| Family | Polypodiaceae |
| Type | fern, perennial, indoor plant |
| Height | 16 to 20 inches (40 to 50 cm) |
| Exposure | part sun, shade |
| Soil | ordinary |
| Foliage | evergreen |
| Flowering | none |
It loves shade, and will excel in decorating those hard-to-grow dark spots of the garden.
All year round for plants in containers, as long as it is neither freezing nor too hot.
Perfectly suited to indoor growing.
It sometimes appears on its own in unexpected places.
It won’t need much soil, and is a great addition to a flowered stone wall.
To grow this fern in a pot, indoors, you’ll simply need to make sure it gets enough water.
However, at the same time, the soil must drain extremely well. A great option is to grow it as a hanging fern and to dunk it in water twice a week, then letting it drip dry.
The same fern behaves very differently depending on where you put it. Here is what each situation asks of you, indoors and out.
| Where to grow | Light | Water and soil | Key point |
|---|---|---|---|
| Shaded garden bed | Full shade or part sun | Almost any soil, well drained | Decorates hard-to-grow dark spots |
| Stone wall or rocky ground | Shade | Very little soil needed | May even appear there on its own |
| Pot indoors | Away from full sun | Enough water, but extremely free-draining soil | Never let the soil dry off |
| Hanging fern | Shade | Dunked in water twice a week, then left to drip dry | Drainage is what decides success |
| Indoor wall garden | Shade | Watered regularly | Slow growth, never above 20 inches (50 cm) |
Whichever spot you choose, drainage and shade matter far more than the soil itself.
They don’t need any pruning. Eliminate dead leaves after they’ve withered away, once they’re dry.
Removing a Phyllitis scolopendrium fern that has taken up too much space might be a bit difficult: roots are usually firmly wedged in nooks and crannies on walls and rocky terrain.
Just keep coming back at it for a few more times, removing any growth and coaxing a bit more roots out. Eventually the fern’s root ball will deplete its nutrient reserves and will die off.
Beyond the plain strap-leaved species, hart’s tongue has given rise to a long list of frilled, crested and lacerated forms, most of them evergreen and grown exactly the same way. The table below compares those most likely to turn up in garden centres and mainstream catalogues.
| Variety | Frond character | Size band | Best placed |
|---|---|---|---|
| ‘Kaye’s Lacerated’ | Broad fronds with jagged, torn edges | Compact | Pots, shaded edging |
| Crispum Group | Broad fronds with deeply crimped frilly margins | Medium to large | Shaded bed, as a specimen |
| Cristatum Group | Fronds forked and crested at the tip | Medium | Front of a shady border |
| Undulatum Group | Wavy, rippled frond margins | Medium | Containers and shaded beds |
| Marginatum Group | Lobed, flanged edges with raised ribs | Compact to medium | Rockwork and low walls |
| ‘Crispum Bolton’s Nobile’ | Evenly frilled, upright, usually spore-free | Medium to large | Feature plant in shade |
| ‘Muricatum’ | Rough, puckered, warty leaf surface | Compact | Close-up spots and containers |
| ‘Ramocristatum’ | Branched fronds ending in crests | Medium | Shaded border, specimen pot |
| ‘Furcatum’ | Simply forked frond tips | Medium | Shaded bed, easy grower |
| ‘Capitatum’ | Heavy rounded crest at frond tip | Medium | Specimen pot in shade |
| ‘Fimbriatum’ | Finely fringed frond edges | Compact to medium | Containers, indoor shade |
| ‘Conglomeratum’ | Congested, crumpled, tightly bunched fronds | Dwarf | Small pots, wall pockets |
This small fern execrates full sun and will always prefer shaded, often more damp areas.
Its growth is relatively slow, and it won’t grow any taller than 20 inches (50 cm). Ideal for an indoor wall garden! As an indoor plant, water it regularly to ensure the soil doesn’t dry off.
The term “hart’s tongue” comes from the appearance of each leaf: like a little tongue of the male deer. The name for a male deer is “hart”.
To reproduce, hart’s tongue produces spores that are lined up on the underside of leaves. These lines look like small millipedes or centipedes: this is where the botanical name “scolopendrium” comes from. Indeed, it’s the old latin word for those two insects!
Indoors, if the leaves turn black, it’s usually because the air is too dry.
Dip the pot in a pail of water and place the plant in a cooler spot, away from heat sources.
