Ruby Rasp Fern

Ruby rasp fern (Doodia aspera 'Rough Ruby') is an Australian native fern whose new fronds emerge deep red against mature green ones, so the clump carries two colours at once. It holds at about 35cm tall and 40cm wide, a groundcover rather than a specimen. Tough, pet friendly and happy in dry shade, it solves a part of the garden most plants refuse.

Why you'll love it

• Red new growth, constantly. Each flush hardens slowly from deep coppery red to green, so there is always fresh colour in the clump.
• An Australian native that behaves. Native to the east coast, it forms a slowly spreading clump rather than taking over a bed.
• Pet friendly. Not toxic to cats or dogs.
• Dry shade specialist. Once established it is drought tolerant, which very few ferns are, and it copes under the canopy of mature trees.

Where it works best

Groundcover and mass planting. Plant 40cm apart under trees or along a shaded fence line. The fronds close into a continuous low layer within two seasons.

Borders and edging. The clumping habit gives a soft, informal edge along a shaded path.

Pots and rockeries. It sits well in a shaded pot, and in a rockery it colonises the cool pockets between stones.

Growing ruby rasp fern in Australia

Position and climate. Partial to full shade with filtered light, not deep gloom, brings out the strongest red. It suits tropical, subtropical, warm temperate and cool temperate gardens, and takes light frost only, so in frosty inland and alpine districts plant it under a canopy.

Soil. Free draining soil with organic matter through it. Ferns hate sitting wet, so improve heavy clay with compost and coarse sand. Mulch to about 50mm, clear of the crown.

Water and feed. Water twice a week through the first summer. After that it manages dry spells, though fronds look better for a soak in prolonged heat. Feed lightly in early spring with a low phosphorus native fertiliser.

Pruning. Cut old or browned fronds off at the base in late winter to make room for the new red flush. Never shear it like a hedge.

What to expect when it arrives

It is grown in tube stock and in 140mm pots sold in packs of ten. Tube stock is the economical way to cover a large shaded area and is currently on backorder, so check before planning around it. The 140mm plants are established clumps, better for a smaller bed or a pot.

Fronds bruise and dry at the tips in a box, so judge the plant by the crown at soil level, not the outer fronds. Plant within a few days, water in well, keep it shaded, and expect new fronds within four to six weeks in the warmer months.

Delivered Australia wide, delivery from $29.95. Every plant is covered by our 30 day healthy plant guarantee.

Plant care guides and related reading

• Where ferns actually thrive in a garden
• The best groundcover plants for shade
• Browse ferns for shaded areas
• See more Australian native plants

Common questions

How far apart should I plant it?

Forty centimetres apart, about six plants per square metre. Wider spacing still fills in, it simply takes another season.

Does it flower?

No. Ferns reproduce by spores. The red new fronds give this one its colour.

Will it grow in full sun?

Not well. In full sun the fronds bleach and crisp at the edges. Give it partial to full shade.

Is it safe around pets?

Yes. It is not toxic to cats or dogs, so it suits shaded parts of a garden where pets spend the day.