Carol Klein suggests her favourite ferns to try now
These magical favourites of mine are reminding us that the garden is still alive
Evergreens are in short supply in the garden at Glebe Cottage. There are a few conifers, now quite stately and venerable, and there’s a sinuous spine of variegated box that runs across the length of the ‘hot beds’, providing a background for summer flowers, but right now a splendid feature in its own right is reminding us that the garden’s still alive. On the shady side of the garden, once hellebore leaves have been removed, green is provided almost exclusively by evergreen ferns.
The most ubiquitous, clothing many of the banks and hedges both in the garden and the surrounding countryside, is the polypody. Such a lovely name – the first bit, ‘poly’ from Latin, meaning many, the second part from the Greek for foot.
This is a fern that always gives you the reassurance that life continues. Even when it’s laid low by the farmer’s flail, within a couple of weeks it reasserts itself, seemingly with renewed vigour. In the garden, too, it’s everpresent alongside another native evergreen fern, the hart’s tongue fern, Asplenium scolopendrium.
In contrast to the muchdivided fronds of the polypody, those of the hart’s tongue are entire, smooth and shiny. Its new fronds are among the most pristine foliage in the garden and their formation is conspicuous, creating a shuttlecock as each new frond unfurls.
In contrast to the strong architectural form of the hart’s tongue, the lacy filigree fronds of the soft shield fern Polystichum setiferum make an eye-catching variation. The species has lacy fronds and there are selections with even frillier foliage, Polystichum
‘The more unusual ferns have been planted deliberately, but the great majority put themselves where they want to be’
setiferum Divisilobum Group and ‘Plumo-Densum’ are two of the most ornate.
Unusually, this is one of the few ferns that can be increased vegetatively rather than by sowing its spores. In some forms embryonic ‘fernlets’ are formed along the midribs of the fronds and, with careful nurturing, they can eventually be detached and grown on.
Ferns are some of the oldest plants on earth. Their ancestry stretches back hundreds of millions of years and makes flowering plants look like newcomers who have just turned up. Throughout aeons they’ve hardly changed, there’s no reason for them to do so, and they’ve evolved a survival strategy that’s virtually indestructible.
Although fern species may have evolved very gradually and continuously during this time (there are more than 10,000 species worldwide), their sex life has remained unchanged. And a very special and individual sex life it is.
How do they make more of themselves? Flowering plants reproduce each generation from seed; ferns have no flowers and set no seed. It’s because of this phenomenon, unexplained until we could gaze down microscopes, that ferns have had a mystical – almost magical – significance. Because they’ve evolved a strategy for reproduction without flowers and seed, they’re seeped in mythology. Ferns have long associations with witchcraft and magic. The fact that they’re plants that need no direct light adds to the intrigue.
And it’s this feature too that makes them such important garden plants, though during the winter it’s the evergreen varieties that come into their own.
The garden here at Glebe Cottage is full of ferns. The more unusual selections have been planted deliberately but the great majority have put themselves where they want to be, sometimes between the crevices in walls, sometimes in flower beds or at the edge of paths.
One evergreen fern that has been given a privileged position here at Glebe Cottage is a splendid specimen of the chain fern, Woodwardia radicans. This is a fern and a half – its handsome fronds can grow up to a metre long. We grow it on a damp bank with a huge Mahonia japonica just across the path, which acts as a shield from blasting wind.
Woodwardia, too, produces bulbils or fernlets at the tips of its fronds and can make quite a colony. Some of the woodwardia clan have red new fronds, an exciting departure on the fern front. Dryopteris erythrosora from Japan is another fern with surprising colour. Its new fronds are orange and the colour persists until gradually with age it becomes more muted, eventually ending up as an attractive olive green.