Wheki / Rough Tree Fern (Dicksonia squarrosa): Fast-Growing, Clumping New Zealand Tree Fern

Overview

Wheki (Dicksonia squarrosa), also called rough tree fern or harsh tree fern, is a distinctive New Zealand tree fern known for its **fast growth, clumping habit, and retention of dead fronds** as a brown "skirt" around the trunk. It produces multiple slender trunks (10–20 feet) from a spreading base, each crowned with harsh, stiff, dark green fronds 6–10 feet long. The persistent dead fronds and rough, bristly trunk give it a wild, unkempt beauty.

Unique Characteristics

• Clumping Form: Multiple trunks from a single base—unusual for tree ferns.
• Frond Skirt: Dead fronds hang down, protecting trunk and hosting epiphytes.
• Rapid Growth: Among the fastest tree ferns.

Culture

Partial shade; moist, well-drained, humus-rich soil. Water trunk and crown. Tolerates more sun and wind than D. antarctica. Frost tender below 25°F (-4°C); USDA zones 9–11. Spectacular in groves or as a multi-trunk specimen.

Taxonomic Profile

Wild, clumping, and fast—wheki brings a primeval grove effect to mild-climate gardens.