Maidenhair Fern
Adiantum raddianum
also called adiantum
Fronds fine enough to read as green lace, and just as unforgiving — one dry afternoon shows up in crisped edges for weeks.
- Type
- Houseplant · Perennial
- Botanical family
- Mixed / other
- Foliage color
- Green
- Sunlight
- Part shade
- Feeding
- All-purpose balanced
- Frost tolerant
- No
- Mar–Dec Spring Growth
- Jan–Mar Spring Growth
- Plant spacing
- 15.7 in
- In-row spacing
- 15.7 in
- Between rows
- 19.7 in
- Square-foot density
- Not suited to SFG
- Root system
- A creeping rhizome with wiry black roots
- Working depth
- 4–12 in
- Can reach
- 18 in down where the soil allows
- Spread
- 16 in–2.5 ft across, about 1–2× the width of the plant
- Shallowest pot
- 8 in of soil
The rhizome runs at the surface under leaf litter, which is exactly where a fern wants it: covered, damp and never disturbed. Bury it in soil and it rots, leave it bare and it dries, so leaf mould over the top is the whole of its cultivation.
The habit is Maidenhair Fern’s own; the figures are what that habit usually comes to at this size, not a measurement of this species. Roots follow the soil either way: a compacted pan, a high water table or heavy clay stops them well short of any of it, and deep open ground lets them go further.
- Scale insects Scale insects clinging to the frond stems
- Root & crown rot Root rot where soil stays waterlogged with nowhere to drain
- Crispy brown fronds after a spell of dry air or dry soil
Beneficial predators that hunt this plant's pests — grow their favourite flowers nearby to recruit them. companion plant
- Hoverfly SyrphidaeHunts Scale insects
Bee-mimicking flies whose legless larvae graze aphid colonies clean while the adults pollinate. A ribbon of shallow, nectar-rich flowers kept in bloom all season recruits wave after wave of them.
- Ladybird (lady beetle) CoccinellidaeHunts Scale insects
The gardener’s favorite ally: adults and their alligator-shaped larvae each eat thousands of aphids, plus scale, mealybugs, and other soft-bodied sap-suckers. Grow flat, open flowers for the adults and never spray a colony that ladybird larvae are already working.
Green-leaved houseplants, like this one.
The Cottage Garden Companion — the gardener's herbarium at cottagegardencompanion.com