Fabaceae
Kōwhai: Medicinal Uses & Care Tips
Sophora microphylla
A hardy, low-maintenance tree once established. It requires full sun or partial shade, well-drained soil, and moderate watering that decreases as it matures, as it is quite drought-tolerant. Avoid overwatering and nitrogen-rich fertilizers, which promote soft growth prone to pests.
Every 14 days
Bright indirect
-8° - 32°C
30% - 70%
Categories
What is Kōwhai?
Kōwhai (Sophora microphylla) is a medium-care plant from the Fabaceae family. The kōwhai (Sophora microphylla) is an evergreen tree endemic to New Zealand, where it grows from coastal areas to low montane environments. It reaches between 13 and 26 feet in height in cultivation (up to 82 feet in the wild), featuring pinnate leaves with small leaflets and weeping branches. In s...
Kōwhai grows up to 8.0m, spread of 600cm, watering every 14 days, -8°C – 32°C, 30–70% humidity. It is not suitable for indoor environments and not safe for pets.
Without precautions, ingestion can cause irritation in pets. Keep out of reach of cats and dogs.
How to Care for Kōwhai?
TLDR: Kōwhai needs Bright indirect, watering every 14 days, and temperatures between -8-32°C with 30-70% humidity.
How Often Should You Water Kōwhai?
Water regularly during the first year to help establish deep roots; thereafter, water only during prolonged dry periods. In pots, water 1-2 times per week during warm weather and every 1-2 weeks during cold weather, avoiding waterlogging.
How Much Light Does Kōwhai Need?
Prefers full sun; tolerates partial shade, although with less light the branches stretch and the habit becomes less compact. Place in a location sheltered from strong winds.
What Is the Best Soil for Kōwhai?
Requires a well-drained substrate (sandy, loamy, or calcareous); tolerates acidic to neutral pH. In heavy or poorly drained soils, it is prone to root rot, so it is advisable to improve drainage with organic matter or sand.
What Pot Should You Use for Kōwhai?
If grown in a pot during its juvenile stage, use a wide and deep container with several drainage holes and a well-draining substrate; transplant it into the ground as soon as possible, as it is a large tree unsuitable for long-term container life.
Care Schedule
Fertilize
Every 60 days
What Is Kōwhai and Where Does It Come From?
The kōwhai (Sophora microphylla) is an evergreen tree endemic to New Zealand, where it grows from coastal areas to low montane environments. It reaches between 13 and 26 feet in height in cultivation (up to 82 feet in the wild), featuring pinnate leaves with small leaflets and weeping branches. In spring, it produces clusters of striking, pendulous yellow flowers, considered the country's unofficial national flower. All parts, especially the seeds, are toxic as they contain the alkaloid cytisine.
How to Propagate Kōwhai?
Seed propagation
- Without scarification, germination can take months due to the hardness of the seed coat.
- 1 Scarification
Lightly file or sand the hard seed coat to facilitate water absorption.
- 2 Soaking
Soak the scarified seeds in warm water for 24 hours.
- 3 Sowing
Sow in a well-draining substrate at a shallow depth and keep moist until germination.
Materials needed:
Semi-hardwood cutting
- Bottom heat significantly improves the success rate.
- 1 Cutting
Take semi-hardwood cuttings of at least 6 inches in spring or summer.
- 2 Hormone application
Dip the base in rooting hormone and plant in a well-draining substrate.
- 3 Rooting
Maintain with bottom heat and constant humidity until rooting occurs, in about 4-5 weeks.
Materials needed:
How Big Does Kōwhai Grow?
TLDR: Kōwhai can reach up to 8.0m tall with Medium growth rate.
Max height
8.0m
Spread
6.0m
Growth rate
Medium
Foliage
Evergreen
Warning: Toxic Plant
This plant can be toxic if ingested. Keep out of reach of:
Plant Uses
Ornamental
Great for decoration
Medicinal
Medicinal properties
Medicinal Uses
- Bark infusion traditionally used for sore throats and fever
- Traditional Māori topical use for wounds and skin conditions (under supervision, given the plant's toxicity)
Is your plant showing symptoms?
Click on the symptom to discover possible causes:
What Diseases Commonly Affect Kōwhai?
TLDR: Kōwhai is susceptible to 9 known diseases. Monitor regularly for early detection.
Root Rot
Root rot is a serious fungal disease that affects the root system of plants, causing them to decay and die. It is primarily caused by overwatering, poor drainage, or soil-borne fungi such as Pythium, Phytophthora, Rhizoctonia, and Fusarium. The disease thrives in waterlogged conditions where roots are deprived of oxygen, making them susceptible to fungal infection.
Phytophthora Root Rot
The Phytophthora genus consists of soil-borne oomycetes (water molds) that act as plant pathogens, primarily affecting trees and woody plants. It typically spreads through the root system, leading to systemic decline and eventual plant collapse.
Fusarium Wilt
Fusarium wilt is a serious fungal disease caused by the soil-borne fungus Fusarium oxysporum. The fungus invades roots and blocks the water-conducting vessels (xylem) of the plant, causing progressive wilting and eventual death. Host-specific forms of the pathogen exist that attack different plant species.
Verticillium Wilt
Verticillium wilt is a soil-borne fungal disease caused primarily by the fungi Verticillium dahliae and V. albo-atrum. These pathogens infect plant roots and grow within the vascular tissues, blocking water and nutrient transport, resulting in wilting and eventual plant death. The disease affects over 350 plant species including vegetables, fruits, ornamental flowers, and trees. The fungi can survive in soil for more than 10 years as resistant structures called microsclerotia.
Meaning & Symbolism
Considered the unofficial national flower of New Zealand, the kōwhai holds great cultural value for the Māori, who planted it near their pā (fortified settlements) and used its hard wood for paddles and tools, as well as bark infusions in traditional medicine.
Compare with similar plants
| Attribute | Difficulty | Light | Watering | Pet Safe |
|---|---|---|---|---|
| Dark Fieldcap | Medium | Low light | 2d | ⚠️ |
| Azalea | Medium | Partial shade | 3d | ⚠️ |
| Muriel's Bamboo | Medium | Partial shade | 3d | ✓ |
| Bougainvillea | Medium | Direct sun | 7d | ⚠️ |
