Maidenhair fern Walter Siegmund / CC BY 2.5
garden

Maidenhair fern

Adiantum

EdibleMedicinalToxic — Use Caution

Overview

One of the most delicate and graceful ferns, maidenhair has jet-black wiry stems supporting fan-shaped fronds of tiny, soft green leaflets. It is widespread across the globe and has been used in herbal medicine since ancient Rome — syrup of maidenhair (capillaire) was once a popular apothecary preparation. In the garden, it thrives in consistently moist, shaded conditions near water features.

Growing Conditions

LightPartial Sun
MoistureModerate
Hardiness Zones8 — 11
Height0.3m
Spread0.3m
Growth HabitFern
Pollinator Valuenone

Companion Planting & Soil

Good Companions

HostaBleeding heartAstilbeJack-in-the-pulpit
Soil pH6 — 7.5
Soil TypeRich, moist, humusy, well-drained soil; loves lime

Planting Calendar

When to sow, transplant, and harvest by growing zone.

ZoneActionMonthsNotes
Cold (1-2) Transplant May — Jun Plant in spring; delicate fan-shaped fronds on black wiry stems; moist shade
Cold (1-2) Bloom May — Sep No flowers; airy fan-shaped fronds emerge from black stems; deciduous
Cool (3-4) Transplant Apr — May Plant in spring; needs consistent moisture and high humidity; avoid wind
Cool (3-4) Bloom Apr — Oct Graceful deciduous fronds; pairs with wildflowers in spring
Moderate (5-7) Transplant Mar — Apr Plant in spring; rich, moist, humusy soil in shade; elegant woodland accent
Moderate (5-7) Bloom Mar — Oct Delicate fronds spring through fall; goes dormant in winter
Moderate (5-7) Divide Apr — May Divide carefully in spring; keep divisions moist until established
Warm (8-9) Transplant Feb — Mar Plant in late winter; deep shade and constant moisture essential
Warm (8-9) Bloom Feb — Nov Long season; fronds scorch in dry air
Hot (10+) Transplant Nov — Dec Plant in fall; challenging in hot dry zones — needs microclimate
Hot (10+) Bloom Feb — Oct Needs sheltered microclimate; mist regularly

Uses

Medicinal

  • Traditional cough and respiratory remedy (capillaire syrup)
  • Hair rinse historically used for strengthening and shine
  • Demulcent tea for sore throats

Other Uses

  • Elegant shade garden and terrarium plant
  • Houseplant for humid, bright indirect light conditions

Safety Notes

Although we have found no reports of toxicity for this species, a number of ferns contain carcinogens so some caution is advisable[200]. Many ferns also contain thiaminase, an enzyme that robs the body of its vitamin B complex. In small quantities this enzyme will do no harm to people eating an adequate diet that is rich in vitamin B, though large quantities can cause severe health problems. The enzyme is destroyed by heat or thorough drying, so cooking the plant will remove the thiaminase[172].