Libertia grandiflora
New Zealand Iris
Overview
Libertia grandiflora is an evergreen, clump-forming perennial in the iris family, growing 2–3 feet (60–90 cm) tall and 24–30 inches (60–75 cm) wide. The narrow, strap-shaped dark green leaves are leathery and arch outward from the base in dense tufts. In late spring and early summer, branched flowering stems rise above the foliage carrying clusters of three-petaled white flowers about 1 inch (2.5 cm) wide, with the three outer tepals larger than the inner ones. Rounded seed capsules follow, ripening to orange-brown and persisting into winter. The plant grows from short rhizomes and slowly forms a wider clump. It tolerates full sun to light shade and a range of soils with good drainage, and the older leaves brown at the tips in dry or cold spells. It is hardy to about USDA zone 8 and may be cut back by hard winters in colder gardens. Flowering is heaviest in an open, sunny position.
Native Range
Libertia grandiflora is native to New Zealand, where it grows at forest margins, in scrub, and in open grassland on both main islands. It is adapted to a mild, moist temperate climate.Suggested Uses
Libertia grandiflora is used in mixed borders, gravel gardens, and coastal plantings for its evergreen foliage and early-summer flowers, spaced 18–24 inches (45–60 cm) apart. It combines with grasses and other clump-forming perennials. The browning of older leaf tips in dry or cold spells limits its use where year-round crisp foliage is wanted.How to Identify
Appearance
Size & Dimensions
Height2' - 3'
Width/Spread2' - 2'6"
Reaches mature size in approximately 3 years
Bloom Information
Flowering occurs in late spring and early summer, roughly May to June. Branched stems carry successive clusters of white three-petaled flowers above the foliage over several weeks. Orange-brown seed capsules develop afterward and remain into autumn and winter.
Detailed Descriptions
Foliage Description
Dark greenGrowing Conditions
Sun Requirements
Requires 4-10 hours of direct sunlight daily
• Full Sun: 6+ hours of direct sunlight
• Partial Shade: 3-6 hours of direct sunlight
• Full Shade: Less than 3 hours of direct sunlight
Care & Maintenance
Care Guide
Libertia grandiflora grows in full sun to light shade and well-drained soil of average fertility, with a pH between 5.5 and 7.0. It tolerates a range of soils but needs drainage to avoid winter rot in the crown. Once established it withstands short dry spells, though steady moisture supports denser foliage. The older outer leaves brown at the tips and can be pulled away to keep the clump fresh. It is hardy to about USDA zone 8 and may be damaged by hard winters in colder areas. Division in spring renews older clumps that thin out at the center.Pruning
Browned or tatty outer leaves can be pulled or trimmed away in spring to tidy the clump. Spent flowering stems can be removed once the seed capsules fade, or left for winter structure. No other pruning is needed.Pruning Schedule
J
F
M
A
M
J
J
A
S
O
N
D
early spring
Container Growing
✓ Suitable for container growing
Minimum container size: 3 gallons