Sophora spp.
Necklacepods
Both hemispheres (Asia, Pacific, New Zealand, Americas)
Overview
Sophora spp. is a genus of about 45 species of trees, shrubs, and a few perennials in the pea family, distributed across warm-temperate and tropical regions of both hemispheres, including Asia, the Pacific, New Zealand, the Americas, and oceanic islands. Plants range from low shrubs to trees 6-40 ft (1.8-12 m) tall, with pinnately compound leaves divided into many small leaflets. The flowers are pea-like, borne in hanging or upright clusters, and most often yellow, though some species are white, cream, or violet; the New Zealand kowhai, S. microphylla and S. tetraptera, carry tubular golden-yellow flowers that draw nectar-feeding birds. After bloom the genus produces seed pods constricted between the seeds into a beaded, necklace-like string, which gives several species the name necklacepod. The hard seeds of many species contain quinolizidine alkaloids and are toxic if eaten. Sophora spp. grows in full sun and well-drained soil, tolerating coastal exposure, heat, and drought once established, though most species are frost-tender to only moderately hardy. Growth is often slow, and several species fix nitrogen through root nodules.
Native Range
Native across warm-temperate and tropical regions of both hemispheres, including eastern Asia, the Pacific islands, New Zealand, Chile, and the southern United States, with species on coasts, in forests, and in dry scrub. The kowhai species are native to New Zealand.Suggested Uses
Grown as specimen and street trees, coastal and dry-garden shrubs, and screening plants, with the kowhai used as a flowering small tree for nectar-feeding birds. Container culture suits frost-tender species in cool climates.How to Identify
Appearance
Size & Dimensions
Height6' - 40'
Width/Spread6' - 25'
Bloom Information
Flowering occurs mainly in late winter and spring, generally from August in the Southern Hemisphere kowhai and in spring elsewhere, with some tropical species flowering through the warm season. Clusters of pea flowers last several weeks. Nectar-feeding birds visit the tubular-flowered species during bloom.
Detailed Descriptions
Flower Description
Yellow, cream, white, or violetFoliage Description
Green, pinnateGrowing Conditions
Sun Requirements
Requires 6-12 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
Water & Climate
Care & Maintenance
Care Guide
Grow in full sun in light, well-drained soil; the genus tolerates poor, sandy, and rocky ground and resents heavy, wet conditions. Water young plants until established, after which most species tolerate drought, heat, and coastal salt. Hardiness varies widely, from the frost-tender tropical shrubs to the kowhai, which withstand light frost in USDA zones 8-10. The hard seeds contain quinolizidine alkaloids and are toxic to people and animals if swallowed. Seed germination is slow unless the hard coat is nicked or soaked. Many species fix their own nitrogen and need little feeding.Pruning
Prune lightly after flowering to shape and remove dead or crossing wood. The genus tolerates only moderate cutting and is slow to regrow from old wood. Remove spent pods if self-seeding is unwanted.Pruning Schedule
J
F
M
A
M
J
J
A
S
O
N
D
late spring
Container Growing
✓ Suitable for container growing
Minimum container size: 7 gallons