Small Plants for the Fern Border
The Mixed Fern Border
Smaller subjects for the front of the fern border are numerous and very varied. There are a number of bulbs and corms which lit in with the informal planting so desirable in such a scheme. Such subjects as the chionodoxas, eranthis, scillas, dwarfand snowdrops worked in here and there by scattering a mixture of them, so that there are no obvious concentrations of any particular kind (planting the bulbs where they fall), will provide a mosaic of colour, amongst the ferns, which will appear like a natural woodland carpet of these colourful miniatures.
The larger daffodils are better avoided as they are just a little too tall and die down untidily just as the ferns are unfolding their fronds. Colchicums, too, although magnificent in autumn when their colourful blossoms appear without foliage, have foliage which comes up in spring strong and clumsy looking, quite inappropriate amongst the ferns with which they do not blend. The trilliums and erythroniums are ideal plants for foreground planting.
There are several colour forms of Erythronium dens canis — the dog’s-tooth violet — was there ever such an inappropriate popular name for a plant? The ‘dog’s-tooth’ part refers to the corms, which are thought to resemble the canine teeth of a dog, though horse’s tooth might be nearer the mark, but where the ‘violet’ part comes in, I cannot imagine; I cannot think of a flower less like that of a violet. The American species, of which there are several, are all lovely graceful woodlanders. The yellow E. tuolumnense and its cultivar E.t. ‘Pagoda’ are quite amenable and gradually form small clumps.
The trilliums revel in the woodland type of. They have great charm: their popular name ‘Trinity flower’ refers to the three-petalled , and the fact that they have but three leaves in a whorl below the flowers.
T. grandiflorum is pure white though there is a very rare pink form, T. sessile is deep purple, and there are numerous intermediate species.
We must not forget anemones, all very dainty and typical inhabitants of our own and alpine woodlands. The various forms of Hepatica triloba and H. angulosa — formerly known as Anemone hepatica and A. angulosaare ideal, making steadily increasing clumps. These should be allowed to grow undisturbed, as they resent root disturbance.
Anemone nemorosa, our own native windflower, has many colour forms; Alleni, large lavender, ‘Celestial’, and Robinson, clear blue, and I he double alba plena all are charming, and will run about freely, but without making themselves a nuisance. The autumn-flowering species A. bupebensis, and A. japonica are rather large and I think they do not blend very well. There are one or two dwarf forms which might be used.
A relation of the epimediums, Vancouveria hexandra, is another useful carpeter for foreground planting. The foliage is airy and pleasing, the demure while flowcrs are dainty though small.
Tiarella cordifolia, the foam flower, is another delightful carpeter, about six inches when in flower, with pure white, very fluffy heads of small flowers. It spreads by. Its hybrid, Heucherella ‘Bridget Bloom’, is not so invasive and has dainty spires of pale pink. Some of the heucheras, or alum roots, are American woodlanders, and though some of the species are rather coarse and indifferent in flower, the dwarfer H. sanguinea and its many cultivars are dainty and very effective in the mass. They may be raised easily from seed and so provide a range of shades from pink to scarlet, but the named varieties have been selected for pre-eminence in form and colour.
An interesting development in gardening is the peat wall, and this form of gardening has proved excellent for growing certain peat-loving plants which are not so happy on the flat. Generally speaking peat walls are built up with peat blocks just as one would build up a dry wall with stone. As most peat-loving plants are also moisture-loving plants, the walls are not built more than a foot high, and they are filled in behind the wall with lime-free peaty soil to make level or gently sloping beds.
Often two or more walls are made, a few feet apart, with level beds between, perhaps with stepping-stones placed to allow easy movement among the plants for maintenance.
Examples of peat walls which are fairly well established may be seen in our botanic gardens. A friend of mine who lives in Harrogate has a delightful example in his garden. Not only is there a good collection of Petiolaris primulas thriving in almost a vulgar manner in the peat-wall faces, and many other treasures, but there is a very fine set of ferns looking very much at home. Even the calcicole ferns are thriving in the acid peat, and, of course, it is just the place for flourishing Parsley Fern, Cryptogramma, and the Hard Fern, spirant, the Beech and Oak Ferns and others.
The New Zealand Microsorium diversifolium thrives in the face of such a wall, where it makes a handsome specimen.
While such a peat-wall garden is made in the first instance for growing ericaceous plants and those requiring such conditions, there is no doubt that such a garden provides an ideal habitation for many of our choice ferns, and this is borne out by the frequency with which self-sown ferns appear in such walls. It is hardly necessary to build such walls for the successful cultivation of ferns, except that the calcifuge species might perhaps enjoy a small peat-wall area made for them.
Apart from many of the plants detailed above for planting with ferns, the following paragraphs mention plants particularly suitable for peat gardens.
Once I made a bed for shortias and schizocodons, using old railway sleepers to raise the beds above my limestone soil. This was made up with equal parts of good-quality peat and leafmould, to the depth of a sleeper set on edge, and a generous addition of sphagnum moss was well mixed in. These plants grew amazingly well; they could be lifted at almost any time, divided and replanted, and grew away again perfectly. I used no loam at all. Beds made up with half loam and half the peat and leafmould mixture were nothing like so successful. I proved that this hundred per cent peat and leafmould mixture is ideal for these fascinatingly beautiful Japanese woodland plants.
Other subjects, apart from the enormous numbers of Ericaceae which could be used, apart from the dwarf rhododendrons, cassiopes, phyllodoces and the like which need a book to themselves, which I have grown in similar beds very successfully are: the Japanese poppywort, Glaucidium palmatum; the lovely double bloodroot, Sanguinaria canadensis flare pleno; the wand flower, Galax aphylla, whose circular polished leaves are always attractive, apart from the graceful wands of white flowers.
The prostrate Linnaea canadensis ramps about in such mixtures, forming bronzy-green carpets; its tiny twinflowers appear in due course, on two-inch stems.
I was particularly pleased with a planting of Saxifragra Fortunei purpurea this year, associated with a group of Cystopteris fragilis var. alpina and Astilbe simplicifolia. The glossy purple foliage of the Saxifrage, its spires of odd white flowers, and the bronzy-green foliage of the Astilbe with its six-inch spikes of pale pink, made a lovely picture set off admirably by the finely cut greenery of the Cystopteris.
As background plants to the ferns in peat beds the many kinds of Meconopsis thrive and flower in profusion, the blue-flowered species coming a much better colour in the acid soil. Then the ourisias, New Zealand plants of great charm, all thrive on the peat walls. One could go on indefinitely exploring the many arrangements and combinations, which are endless, of ferns and other plants which can be adapted to fit into any garden where there is some shade.
Ferns in a shrub border do not, to my mind, look well, and the use of shrubs in the fern border is very limited and should be confined to the smaller carpeting shrubs, as, for instance, Pachysandra terminalis in both its green and variegated forms, which will spread by underground runners in woodland soil.
Sarcococca ruscifolia has cheerful green foliage and makes evergreen hush lets of twelve inches, and the Butcher’s Broom, Ruscus, can be quite effective in the shade, when it bears its red berries. Its near relative, Danaea racemosa, is more decorative, with foliage of glossy green and graceful in habit, three feet: or so high, and also bearing red berries.
The Periwinkles, Vinca species, really are too much of a good thing unless there is ample room; the various cultiv ars of V . minor are the only admissible ones and they can be had with white, purple and blue flowers, and one or two double-flowered varieties.
Perhaps Daphne mezereum might be admitted; its perfume in March is delightful, and it does not get too large. Contrary to some writers, I find the majority of Daphnes indifferent to lime, at least in my limestone soil, which has a pH of 8.5.
Some of the dwarf Bamboos make attractive thickets, but they are far too invasive for the small garden and should not be considered unless there is ample room for them to spread around.
Under standard trees, such as the Japanese Cherries, Sorbus species, Laburnums, and Silver Birch, ferns appear to great advantage; their arching fronds contrast perfectly with the slender trunks of the trees, and a selection of good ferns might well be associated with municipal tree-planting in parks and public places.
For waterside planting, which presupposes exposure to sunshine, the Royal Fern, Osmunda regalis, and its near relations will do well if the ground is moist enough. Onoclea sensibilis andtabular grow very well in the open, near water, but in general the exposure to sun so necessary for the wellbeing of water plants is inimical to the full development of many ferns. Where the ground contains plenty of humus ferns will grow in full sun well enough, but never attain their full stature, and their greatest virtue is their preference for growing in places too shady for very many plants to thrive.