18th July 2016
I was helping a client the other day to select something for a shady area in her garden. I immediately thought of using a fern.
Ferns have been around for a while, they first appear in the fossil record during the late Devonian period some 360 million years ago. However, many of the species we see today are believed to have appeared some 145 million years ago during the Cretaceous period.
Ferns, like flowering plants, have a vascular system for transporting water throughout the plant via specialised vessels. However, they produce spores and do not develop flowers or seeds. Some ferns such as Osmunda claytoniana, after the botanist John Clayton, show evidence of evolutionary stasis – having not changed for over 180 million years.
Ferns are typically thought of as inhabiting shady, moist environments but in fact can be found in mountain regions, deserts or in open plains. It seems ferns do well in marginal environments where flowering plants tend to do less well.
Of course some ferns can grow quite large such as the tree ferns for example Dicksonia antartica with a trunk height of over 10m/30ft.
One of the world’s most invasive weeds is an aquatic fern Salvinia molesta and is listed on the UK invasive species list. However, it prefers tropical and sub-tropical environments and is unlikely to reach here. Despite its reputation, research in the Philippines indicates that it is highly effective at cleaning sewage and might become an eco-friendly alternative to cleaning waste water.
A common weed in Crail, Horsetail (Equisetum) is also a fern and can prove very difficult to remove. In fact occasional hand weeding can make the situation worse by aiding its spread through any small pieces left behind. However the main problem with horsetail is the fact that it has a root system that can go down 2m/6 ft or more. It is best treated with glyphosate (Roundup) in June or by frequent weeding.
As to the fern I recommended: well, I suggested planting Adiantum raddianum – seen on the right. This is perfect for overhanging a rock on a rockery or by a water feature and is tolerant of most soil types.