Architectural Plants. Christine Shaw
Читать онлайн книгу.and grown on singly. The main method of fern production, though, is by using spores. These spores are stored on the backs of mature fronds usually in formal lines. The procedure of gathering spores, which are the size of tiny dust particles, sterilizing every piece of equipment you use, fiddling around with seed trays, using polythene covers to retain humidity, watching green slimy substances form, followed by microscopic plants, which have to be separated from all the sludge that has formed, is all too much for most gardeners, who are sensible enough to leave it to the experts. Apart from the Tree Ferns, most other types of fern are not expensive enough to warrant such a chore.
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Woodwardia radicans has huge jungly fronds up to 1.8m (6ft) long.
Hart’s Tongue Fern
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Asplenium scolopendrium is a rather un-ferny-looking fern with entire fronds instead of the usual filigree style of foliage associated with ferns.
The fronds of Asplenium scolopendrium are fresh apple-green with a waxy surface and wavy edges. The undersides are often well covered with thick rows of chocolate-coloured sori (spore cases). It is not a large fern, reaching a maximum height and width of only around 6ocm (2ft). In spacious gardens it can be planted in groups for more impact, although it is quite noticeable as a single specimen.
This evergreen fern is extremely tough and can cope with very low temperatures and a wide range of conditions that many other ferns would not tolerate. Large amounts of lime or chalk in the soil cause no problems at all. It also copes with more sun and less water than would normally be expected from a fern. I have a small plant that has grown from a spore blown by the wind into a tiny space between a concrete path and the bottom of a terracotta pot. I’m not sure what it lives on, and its size is certainly somewhat diminished, but it has lived there quite happily for three years.
Although this fern is tolerant of less than perfect conditions, much better results will be achieved with a light, alkaline soil, frequent watering and a shady, well-drained planting position. Ferns must be planted into the ground very gently, as the roots hate to grow through soil that has been heavily compacted. Fern roots are idle things that enjoy an easy journey.
Feeding is usually unnecessary unless the soil is really poor. A generous helping of leaf mould would help, but this isn’t always easy to obtain. Alternatively, add a small amount of really well-rotted crumbly manure to the surrounding area, or add some liquid seaweed food to a watering can and use this mix every six to eight weeks during spring and summer.
Propagation from spores is best left to the experts, but large clumps of this fern can often be divided quite successfully. The best time for this would be early spring, just before the new season’s growth commences. Pests and diseases are rarely a problem, especially with the straight form. There are lots of cultivars available, with fronds of varying widths and with different degrees of wavy edges. Some are quite acceptable, but they are generally less robust and less vigorous than the basic Asplenium scolopendrium.
Seersucker Fern
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The surface of the fronds is rough to the touch, and puckered like seersucker, hence its common name.
A great beast of a fern, essential to all jungly and leafy planting schemes. Given the right conditions, it could easily reach a height and spread of more than 1.2m (4ft).
Ferns can be fussy plants, and Blechnum chilense is no exception. Shade is essential to keep the fronds a good colour. Although low temperatures can be coped with, milder climates are preferred. The most vital factor for achieving ferns of colossal proportions is a super-abundance of water. The largest specimens of this Chilean monster are nearly always growing on the edges of ponds or streams, where the roots have constant access to water. Waterlogging won’t be tolerated at all, though, so good drainage is important. Planting on a slope or bank in a high rainfall area out of the wind would be a perfect choice.
Soil should be light and crumbly, but using peat on its own won’t be enough to sustain Blechnum chilense. An ideal mix would be equal quantities of leaf mould, peat (or peat substitute) and loam. Leaf mould is a bit of a luxury and not always easy to acquire, but the search is worth the effort. All ferns are happiest planted directly into the ground, but if this is not possible, use a very large container and never let it dry out. Watering ferns is never an easy undertaking, as they need constant moisture without ever becoming too boggy.
When planting, firm the roots in very gently. Fern roots prefer their journey through the soil to be made as easy as possible. Humidity is appreciated, but try to avoid getting the fronds too wet in very cold weather, as this can cause them to blacken. Feeding is not usually required, but the addition of some very old, well-rotted crumbly manure to the surrounding area in spring would be beneficial, especially to poor soils. The only other maintenance to consider is the removal of any older fronds that have turned brown with age. Cut them off with secateurs to keep the plant looking green and healthy.
Propagation is again best left to the experts, but even skilled propagators have trouble with this one, as the spores must be really fresh to succeed. Pests and diseases aren’t usually a problem, although large green caterpillars occasionally feed on the fronds.
Hard Fern or Deer Fern
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The leaf formation resembles the shape of a fish skeleton. This fern is a familiar sight in English woodlands.
The bright emerald-green fronds of this fully hardy, evegreen fern add a bit of cheer to a dark corner of the garden, especially in winter. They also have an attractive glossy sheen to them. Individual clumps can spread very slowly to cover eventually only about 6osq cm (2sq ft), and the maximum height is unlikely to be much more than 45cm (18in). Because of its relatively small stature, planting just one single specimen gives no effect at all to a garden. Blechnum spicant must be planted in much larger groups to give visually pleasing results. In decent-sized gardens, a whole bank or border planted up with just these ferns would look splendid. In smaller gardens, there is still usually enough room to accommodate generous groups of them. Anything less than five would, in my opinion, look rather miserly.
These ferns should never be removed from their natural habitat, tempting as this may be. Apart from the responsible conservationist attitude, they tend not to appreciate being hauled out of the ground and transplanted elsewhere. The chance of damaging their roots and harming the plant is quite high. Instead, always purchase them from a reputable and reliable nursery where they have been propagated professionally and grown on site. Propagating these ferns is quite tricky and is best left to the experts. If you enjoy a challenge, try growing them from freshly ripened spores removed from the parent plant in early autumn.
This fern is happiest in the shade, grown in moist peaty soil with a bit of leaf mould added. Although shade and moisture are preferred, this tough little fern can cope with drier conditions, and will even put up with some sunshine. Neutral to acid soil is necessary – chalk or lime in the soil will give very poor results.
If you can, give this