Prickly Rasp Fern

Prickly Rasp Fern (Doodia aspera, also listed as Blechnum neohollandicum) is the native fern for gardeners who have killed ferns before. It makes a low clump about 40cm tall and 50cm across, and new fronds push out a clear coppery pink before hardening to deep green. It is tougher and more sun tolerant than most ferns, which is why landscapers reach for it.

Why you'll love it

• Pink new growth, repeatedly. Each flush of fronds opens coppery pink, so the clump changes colour several times a year without ever flowering.
• Harder to kill than most ferns. It takes light frost, handles humidity and is drought tolerant once established, which is rare in this group.
• It handles more light. Where most ferns scorch, this one holds up in dappled sun and open shade.
• A neat, low, spreading clump. At 40cm by 50cm it stays in scale under trees and along a path without swamping anything.

Where it works best

Groundcover and mass planting. Plant 40cm apart for a dense groundcover. At that spacing the fronds knit into a continuous low layer within two seasons and shade out most weeds.

Under trees and along borders. It is the natural understorey plant for a shaded bed, softening the base of a tree or edging a shaded path.

Pots and containers. A single clump suits a 300mm pot on a shaded balcony or in a courtyard, where the pink flush shows at close range.

Growing Prickly Rasp Fern in Australia

Position and climate. Part shade to full shade, with dappled morning sun bringing out the best colour in the new fronds. It suits subtropical, warm temperate and cool temperate gardens. It takes light frost only, so hard frosting inland and southern districts want a sheltered spot under a canopy.

Soil. Moist, humus rich, free draining soil. Work compost or leaf litter through the bed before planting and keep 50mm of mulch over the root zone to hold moisture.

Water and feed. Water regularly through the first summer, after which it copes with dry spells better than most ferns, though the fronds look best with steady moisture. A light slow release fertiliser in spring is plenty.

Pruning. Cut older tired fronds off at the base in late winter and the new flush will cover the gap within weeks. Do not shear the whole clump.

What to expect when it arrives

Four sizes are sold: tube stock, 140mm in packs of ten, and 180mm and 200mm in packs of six. Tubes are the value choice for a large mass planting and take a season longer to close over. The 140mm to 200mm plants arrive as established clumps and fill their space faster.

Ferns sometimes arrive with a little frond damage, which looks worse than it is: cut the damaged fronds off and the plant replaces them. Plants are delivered Australia wide, delivery from $29.95, minimum order $300 before delivery, and every plant carries our 30 day healthy plant guarantee.

Plant care guides and related reading

• Getting fern conditions right in your garden
• Browse ferns for shaded positions
• The best groundcover plants for shade
• Compare other Australian natives

Common questions

How far apart should I plant it?

Forty centimetres apart gives a dense continuous groundcover in about two seasons. Stretch it to 50cm if you want individual clumps to read separately along a border.

Is it actually prickly?

Not in the way the name suggests. The fronds have a rough, rasp like texture rather than spines, which is where both common names come from, and it is perfectly comfortable to handle.

Can it take any direct sun?

Dappled and early morning sun, yes, and it manages more light than most ferns. Hot afternoon sun will still bleach and crisp the fronds, so keep it out of that.

Will it survive frost?

Light frost only. In a cold district plant it under a tree canopy or against a warm wall, where the overhead cover takes the worst of it.