Tree Fern

Cyathea dealbata

Physical Characteristics

Cyathea dealbata is an evergreen Fern growing to 9 m (29ft) by 2 m (6ft). See above for USDA hardiness. It is hardy to UK zone 9 and is frost tender. It is in leaf all year. Suitable for: light (sandy), medium (loamy) and heavy (clay) soils. Suitable pH: mildly acid, neutral and basic (mildly alkaline) soils. It can grow in full shade (deep woodland) or semi-shade (light woodland). It prefers moist or wet soil.

Distribution

New Zealand.

Habitats

Woodland Garden Dappled Shade; Shady Edge; not Deep Shade; Bog Garden;

Edible Uses

Edible Parts: Leaves Stem Edible Uses: Pith of the stem[2, 46, 61, 105]. Rich in starch, it is normally roasted but can be eaten raw[193]. Descriptions of the taste vary from bitter, sweet, astringent and like a bad turnip[193]. The core of the plant near the growing tip is used[193], do not confuse this with the trunk of the plant, which is made up of a peaty substance from the decaying roots[K]. Harvesting the stem kills the plant so this use cannot normally be condoned[193]. Young leaves - cooked. Harvested just before they unfurl, they are juicy and slimy, tasting like bitter celery[193].

Medicinal Uses

None known

Known Hazards

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].