Many ferns including a number of native ferns do very well in a moist situation. Moisture availability can be from almost standing water to free draining but moisture retentive soils. Most European or North American moisture loving ferns will take a more saturated soil than Asian species. This is rather a generalisation but Asian ferns are more adapted to receiving heavy summer rainfall as part of the monsoon, which passes through the soil, ie. a moist but well drained soil.
Most ferns like and do better with some moisture in the soil, while some will grow bigger and faster with constant moisture. Fenland or marsh species such as Osmunda, Matteuccia sp, Dryopteris cristata and Thelypteris palustris will grow bigger in marsh or bog conditions but will tolerate slightly drier soils. Often ferns will thrive in full sun in bog but need shade in drier soils.
How to buy moisture loving ferns Ferns are quite widely available in nurseries and garden centres, but for the best advice and range of ferns suitable for your particular situations a specialist nursery is worth visiting or at least obtaining their catalogues. Mail order services are normally available.
Easily Grown Native Species
Asplenium scolopendrium AGM The native hart’s tongue is tough, evergreen, with strap (or tongue) shaped leaves. It grows on most soils but does better on an alkaline soil. Available in a huge range of forms such as:
‘Cristata’ A group of forms with a broad crest terminating the fronds.
‘Fimbriata’ Fronds narrow with a serrated edge.
‘Kaye’s Lacerated’AGM Fronds rounded to 20cm x 20cm with deeply cut lobes.
‘Crispum Moly’ Frond broad with an edge wavy much like a Elizabethan’s collar (or ruff).
Dryopteris dilatata AGM The native broad buckler fern is a deciduous fern to 80cm x 80cm usually found in moist situations in native woods, commonest on acid soil. Widely grown in a wide range of cultivars such as :
‘Crispa Whiteside’ AGM Frond crisped and a pale yellow colour.
‘Grandiceps’ Fronds with a broad terminal crest and subcrest on the side pinnules. Dark green in colour.
‘Lepidota Cristata’ AGM A form with crisped and small crested pinnules and pinnae giving a ruffled appearance. Dark green in colour.
Dryopteris cristata A rare British native only common in the fenlands of East Anglia. Bolt upright with no crests in spite of the name. Easily grown in a moist spot, to 60 cm or so.
Osmunda regalis AGM Widely native to the Northern Hemisphere including Britain it is still found wild in the UK, including Somerset despite large scale collecting. Upright deciduous fern to 180cm, eventually it makes a fine specimen. Sometimes called the flowering fern because of the plume like sporangia atop the fertile fronds. Able to take full sun given unlimited moisture. Good autumn colour turning a russet or reddish brown. Also available in the following cultivars:
‘Cristata’ AGM Crests to all leafy parts of the fronds, tends to be more compact than the species.
‘Purpurascens’ The new opening crosiers in springs have a distinct purple flush, turning green later and the stipe is red or purple coloured all the growing season. Similar size to the species.
Non Native Ferns for Moisture
Matteuccia struthiopteris The shuttlecock fern, one to be wary of as it has a habit of running and multiplying at a rate of knots. It forms a classic
Osmunda cinnamomea AGM The cinnamon fern so named for its fertile cinnamon coloured fronds which arise in the centre of the sterile fronds and are to 1.5m tall given ideal conditions. It seems to need acid soil to grow big.
Onoclea sensibilis The sensitive fern so called for its habit of dying down in Autumn at the first touch of frost. A running habit and moderately invasive, its once cut fronds to 60cm tall make a good landscape plant.
Ferns for moisture retentive soils in shade.
The lady ferns (Athyrium sp) all need some moisture in the soil to do well. This is particularly so with the Japanese species such as Athyrium nipponicum ‘Pictum’ and Athyrium otophorum var. okanum. The native Athyrium filix-femina and its cultivars and forms need some moisture in the soil as do any of the other Asiatic ferns such as Dryopteris cycadina, D.erythrosora,
D. sieboldii and D. walliciana, Polystichum polyblepharum andP. tsussimense as well as genera such as Arachnoides, Cyrtomium and Adiantum. Many North American and European species similarly like some moisture in the soil. This applies particularly to plants such as Dryopteris goldiana and D.marginalis, Polystichum acrostichoides and P. munitum, .Blechnum sp and Woodwardia sp.
Care of your Ferns
Ferns are on the whole pretty easy and don’t need much in the way of looking after, a seasonal trim of dead or dying fronds
and maybe a bi-annual mulch of compost or leafmould laced with bonemeal or seaweed fertiliser will help.
Dividing of ferns is best carried out during the growing season avoiding periods of hot weather and watering in well afterwards. Divide the crowns into separate clumps or individual crowns with a good amount of fibrous roots. Spring is often a convenient time.
Ferns associate with a number of flowering plants in a moist situation be it out in the open by a pond with such things as Ligularia sp, bog Primula species, Rheum, moisture loving Iris, Rodgersia, Astilbe etc. Or in a moisture retentive soil in some shade with such plants such as Hosta, Actaea (Cimicifuga), Deinanthe, Asiatic Epimedium, Asiatic Primulas, Tricyrtis sp and Kirengeshoma to name a few. It’s easy to see that these are also plants from similar environments to the ferns