There are over 1200 species of ferns found around the world from polar regions to the equator, arid zones to rainforest and wetlands. Only a handful is suited to outdoor landscape situations in our local climate.
Ferns have long been associated with tropical and rainforest gardens. Modern landscapers are now using tough ferns around office buildings, architectural designed homes and large residential estates. Modern rendered homes can be softened by the delicate fronds of landscape ferns.
Ferns are ideal for that shady area in the garden where little else will grow. The many foliage textures and shades of green soften and enhance their surroundings and can make it easy to create a lush clam relaxing feel to your garden.
Brief culture requirements
The secret to any fern’s success is the soil… keep it cool, mulched and moist and over 90% of all ferns will thrive. For best looking ferns keep them moist.
Many ferns can be cut back to reinvigorate the plant with fresh fronds. This is possibly best done in late spring in time for summer rains. Do not cut back Cyathea, Doodia, Pteris.
The toughest of groundcovers:
* false bracken (Calochaena dubia) a surprisingly attractive tough fern with soft foliage. Needs room to spread. Looks great in a pot. Good drought tolerance.
* ground fern (Hypolepis and Dennstaedtia) deep green foliage that needs a confined garden bed.
* rough maidenhair (Adiantum hispidulum) with bronze new growth and very hardy but must not be allowed to dry out. Grows best if provided with a little protection.
* common maidenhair (Adiantum aethiopicum) with lovely soft foliage and very hardy but must not dry out. Grows best if provided with a little protection.
Providing height tree ferns cast a wonderful filtered shadow:
* scaly tree fern (Cyathea cooperi) most commonly grown tree fern in the subtropics and tropics with a dark narrow tall trunk up to 6m.
* rough tree fern (Cyathea australis) is a very hardy fern able to tolerant cold conditions better than C. cooperi and C. brownie.
* Norfolk Island tree fern (Cyathea brownii) grows quickly up to 6m with a large truck.
* soft tree fern (Dicksonia antarctica) – best suited to colder climates. Has a think dark trunk.
Dwarf tree fern habits:
* Brazilian tree fern (Blechnum brasiliense) with a trunk which grows to abut 30cm. New growth can be a vibrant red bronze
* dwarf tree fern (Blechnum gibbum) a very attractive plant with a 30cm trunk
* New Caledonian dwarf tree fern (Blechnum moorei) a bolder fern with lighter coloured foliage than B. gibbum
* Fishbone water fern (Blechnum nudum) more suited to cooler climates.
Other good landscaping ferns include:
* rasp fern (Doodia aspera, D. media) hardy smaller growing Australian native ferns with reddish growth. D. aspera is most tolerant of sun and heat.
* serenity fern (Microlepia strigosa) a popular hardy fern for shady areas. Great for pots and tubs. No native to Australia
* limelight fern (Microlepia speluncae) a bold fern for warmer areas with lush lighter green foliage. Great for pots and tubs.
* birds nest (Asplenium australasicum) long lineal fonds in a rosette. Suited to pot culture. Epiphytic in nature
* hen and chicken fern (Asplenium bulbiferum) highly divided fronds with bulbils along the fonds. Bulbils can be planted to mature as new plants. Also good for pot culture
* gristle fern (Blechnum cartilagineum) very hardy Australian native fern
* swamp water fern (Blechnum indicum) ideal of tropical and subtropical landscapes preferring very moist to wet soils. It is good in full sun locations provided moisture is maintained. It clumps but also spreads
* brake ferns (Pteris argyraea, P. albo-lineata, P. albo-lineata ‘Mayi’, P. cretica) require shelter and protection. Attractive and fast growing ferns. Pteris cretica ‘Green Flame’ is the toughest from the Pteris group
For balcony situations ferns need to be tough and look fabulous in a pot:
* false bracken (Calochlaena dubia) – see above
* serenity fern (Microlepia strigosa) – see above
* limelight fern (Microlepia speluncae) – see above
* leather fern (Rumohra adiantiformis) – tough fern with very attractive dark glossy leaves. Can be used in pots and in the ground
* autumn fern (Dryopteris erythrosora) – slow growing clumping fern
* holly fern (Cyrtomium falcatum) – glossy leaves, part sun, clump forming, spores freely
For the ultimate dramatic affect then the king fern (Angiopteris evecta) with fronds up to 5m long cannot be surpassed. However it needs constant moisture and humidity.
Considering waterwise issues, ferns need not be forgotten. Many ferns are drought tolerant once established such as: false bracken, leather fern and Pteris cretica.
More delicate ferns can be grown in gardens although they may require a shady position sheltered from drying winds and regular replenishment of organic matter in the form of mulch.
Ideas for Landscapers:
One of the most innovative landscape ideas has been the ‘living vertical fern walls’ for small courtyards and commercial office developments.
Create vertical height with ferns in hanging baskets.
Avoid using Nephrolepis cordifolia in suburban areas where is may escape into surrounding bushland. However some newer cultivars may be suited to high density urban developments and balcony gardens, although species listed above are preferred.
Credit: Steve Walters, Sonters Fern Nursery, <Wholesale only> firstname.lastname@example.org
Edited by Paul Plant FAIH, freelance Horticultural and Landscape writer