Cultivation of Ferns in the Open
Cultivation of Ferns in the Open
I suppose the first thing to consider in the cultivation of ferns is where to cultivate them. Nowadays the owner of a sizeable garden is somewhat rare, and I think it would be true to say that an increasing, perhaps the greater, proportion of people today live in urban surroundings where land is at a premium.
Even in towns, however, there are many houses with some kind of garden attached, and while in the past the deposit of soot and corrosive chemicals reached astounding amounts per acre, the present favouring of smokeless fuels and ‘clean air’ areas does make it possible to attempt some form of gardening with every expectation of success.
Town gardens and those attached to the more modern blocks of apartments, are often planted up by the estate managers/builders/owners, withwhich soon fade and become untidy, necessitating replanting with summer bedding subjects and other ephemeral displays. Such gardens often are shaded by near-by buildings or even quite enclosed by towering blocks of ‘mansions’ or flats. These are ideal places in which ferns could provide neat, attractive and cheerful foliage throughout the summer months, needing little or no attention, apart from an occasional light hosing to wash off accumulations of dust.
Such varieties as the many forms of Male and Buckler Ferns would stand up well to town gardens and not object to the occasional light hosing. They could well be used to provide verdant underplanting to lie trees in town squares, given adequate preparation of the, and a yearly trim of any withered fronds. To the enthusiast with a few square yards of back garden, prepared to give a little attention now and in, a more extended collection of varieties could be built up, perhaps including some of the evergreen species and varieties which might need more attention in the public gardens than their keepers were able to give.
The vast majority of ferns do not present any particular difficulty in cultivation, and it is quite true to say that many will survive the most indifferent treatment. One has only to look around a few old gardens to find them surviving and even thriving on years of neglect. Even so, to get the best out of ferns it is advisable to provide the most favourable conditions for good root action and healthy development of their foliage. There is so much extra pleasure to be had from the contemplation of really well grown-specimens.
Very few ferns grow naturally in full sun or in very windy, draughty positions. Even those species found only in mountainous districts such as the Holly Fern,lonchitis, attain their best development in hollows between boulders where there is some accumulation of humus and some shelter from tearing winds. I remember finding a colony of this fern in the hills above Inchnadamph in a kind of swallow-hole in the limestone, some thousand feet up. I counted about thirty crowns in a square yard or so; the fronds were fifteen inches or more long, whereas in a limestone cliff near by, more exposed, the average frond was about six inches only.
Incidentally this area combines calcareous and acid formations, and it is possible to stand with one foot on Dryas octopetala, the edge of an acre or more of it on the limestone, the other foot on acid peat amongst callunas and other lime-hating plants, so sharp is the dividing line between the two types of ground.
When one considers that most of the larger ferns are to be found in open woodland, by woodland streams, in the bottoms of hedges or deep in the crevices of limestone pavements, it is evident that the provision of some shade, with a cool root run, and protection from strong winds, are factors which promise the best results. How often has one stood in comparatively still air in a woodland while the wind moans through the upper branches and tosses them about.
Although many ferns love to grow in moist conditions, very few will thrive in heavy, badly drained soil. When one finds ferns growing well on such soils, almost invariably they are situated on steep banks, on the upper slopes of ditches, or where the excess moisture gets away quickly; or they may be growing on slightly elevated mounds above the general level.
In the garden the provision of shade may be achieved by utilising the north side of a house or boundary wall or some other building, which prevents exposure to prolonged sunlight, but is otherwise open to the sky. This type of shade is better than that provided by overhanging branches of trees, because the drip from trees is detrimental to some ferns. If the trees are not directly overhead, the shade cast by the branches dappled shade. Is very good.
Dense shade from overhead tree branches and the consequent steady drip in wet weather is the normal condition, however, for certain ferns, and these seem to relish the environment by making large specimens: such ferns as the Hard Fern,spicant (if the soil does not contain lime), all the different species of Dryopteris excepting D. villarii, the Oak Fern, Gymnocarpium dryopteris, and the Beech Fern, Thelypteris phegopteris, the Soft Shield Fern, setiferum, and, of course, the Filmy Ferns, Hymenophyllum, all thrive in these conditions, the last mentioned only in very rainy districts. Yet I have seen the Oak and Beech Ferns equally happy, though not so large, on bare mountainsides two thousand feet up, amongst boulders and rough scree.
The Broad Buckler Fern, Dryopteris dilatata, is perhaps the most characteristic fern of the denser-shaded areas.
One trouble which can arise from overhead foliage is, if the trees get infested with greenfly, the dropping of honeydew on the fern fronds. This sticky secretion encourages the growth of black moulds which discolour the fern fronds and impair their ability to manufacture plant foods. Fortunately this is not very common, and the trouble can be averted or minimized by spraying the overhead foliage as soon as the aphids appear with some suitable insecticide not harmful to ferns.