Happy in a cool greenhouse Maidenhair ferns, Adiantums, have the reputation of being easy to kill as a houseplant. They just do not like hot dry conditions. Indeed they’re most satisfied in a Wardian case, or even a bottle. Still a cool greenhouse is good and set in dappled shade amongst other plants they usefully hide bare bottoms and ugly pots with their beautiful filigree foliage.
Although you can grow these from spores it’s far easier to buy one and divide the root ball into several. Pot in a free draining mix of sharp sand and leaf-mould and only ever use rainwater, preferably directly to the root ball not over the fronds. Given cool dappled shade then most varieties are not at all difficult. And there are so many to collect, most looking quite familiar, and a few markedly different.
A. Capillus-veneris, Maidenhair or Venus-Hair is found world wide. It’s also known by the less pretty name of Dudder Grass. In the Isles of Arran off the Galway coast the locals would gather this to brew as a tea substitute. There are forty or fifty other species and even more cultivars from all over the world.
A. Caudatum, the Trailing Maidenhair or Walking fern, is found in Africa and the far East, it ‘walks’ by forming new plants wherever a frond tip touches soil. In a hanging basket it behaves like a Spider plant with mini-plants hanging all round. A. cuneatum, from Brazil, an old favourite is tolerant of poorer conditions. It’s given us many improved selections, such as Excelsum, Ideal, Matador and Maximum which are finely feathered, and especially good for cutting.
Kensington Gem is especially suited to the cool greenhouse making a dense head of finely divided fronds. A. decorum from South America has produced several hybrids including the US variety Pacific Maid with an almost parsley like frond. This was crossed with the vigorous A. cuneatum Fritz-Luthii from Switzerland to give the extremely elegant variety Ocean Spray. North America is also home to A. pedatum, the American Maidenhair which is hardy, resembles the Holly fern and can grow up to a couple of feet tall. A sub-variety of this A. pedatum aleuticum is found from Alaska and Quebec all the way down to California.
A. macrophylum and A. peruvianum are holly or Mahonia like with almost prickly ended fronds. A. fulvum and A. hispidulum from Australia and New Zealand, have narrower thinly filled fronds. A. microphyllum from Afghanistan and northern India is near hardy, a sturdy grower and resembles the more common UK forms.
A. edgeworthii from the Himalyas and China is also near hardy and also has conventionally fern shaped fronds. Whereas A. reniforme from the Canary Islands is totally different with kidney shaped fronds. A. tenerum varieties are from the West Indies and central America and have given many choice cultivars including some with rosy shades. And A. polyphyllum from South America is the grandest of all, a gigantic noble maidenhair fern this reaches over four feet tall, with incredibly decorative fronds that start pink, become metallic and finish a light green, this is not easy but well worth finding for a warm greenhouse.