Euphorbia glauca
Euphorbia glauca
Euphorbia glauca, also known as shore spurge, is a rare and striking coastal plant native to New Zealand. It is recognized for its blue-green foliage, red stems, and unique inflorescences. The plant is threatened in the wild but is valued for coastal restoration and gardens. native trees
Image credit: Shore Spurge (Euphorbia glauca). Photo via Wikipedia
Quick Facts
| Scientific Name | Euphorbia glauca |
|---|---|
| Height | 0.3–1 m |
| Spread | 0.5–1.5 m |
| Water Needs | Low; drought tolerant once established |
| Light | Full sun |
| Frost Tolerance | Low; sensitive to frost |
| Salt Tolerance | High; thrives in coastal conditions |
| Growth Rate | Moderate |
| Lifespan | Perennial |
Climate Suitability
| City | Suitability |
|---|---|
| Whangārei | Suitable |
| Auckland | Suitable |
| Hamilton | Marginal (frost sensitive) |
| Tauranga | Suitable |
| Rotorua | Marginal (frost sensitive) |
| Gisborne | Suitable |
| New Plymouth | Suitable |
| Napier | Suitable |
| Whanganui | Suitable |
| Palmerston North | Marginal (frost sensitive) |
| Wellington | Suitable |
| Nelson | Suitable |
| Christchurch | Marginal (frost sensitive) |
| Dunedin | Marginal (frost sensitive) |
| Invercargill | Not suitable (too cold) |
Euphorbia glauca prefers mild, coastal climates and is sensitive to frost. Best suited to frost-free areas.
Growing Requirements
Soil
- Well-draining soil
- Tolerates sandy soils
- pH 6.0-7.5
Light
- Full sun
- Tolerates coastal exposure
- Needs good air circulation
Water
- Low water needs
- Drought tolerant
- Sensitive to overwatering
Uses & Significance
Garden Uses
- Coastal gardens
- Rock gardens
- Accent plant
- Container planting
- Color contrast
Conservation Value
- Coastal ecosystem restoration
- Habitat enhancement
- Dune stabilization
Seasonal Care
- Spring: Best time to plant and divide; check for new growth
- Summer: Water during dry spells; monitor for pests
- Autumn: Mulch lightly to protect roots; remove spent stems
- Winter: Protect from excessive wet and frost; reduce watering
Pruning
Prune Euphorbia glauca in late winter or early spring to remove dead or damaged stems. Wear gloves to avoid contact with the toxic sap. Regular pruning encourages bushier growth and helps maintain shape.
Planting Guide
- Choose a sunny, well-drained site, ideally with sandy soil
- Dig a hole twice as wide as the root ball
- Plant at the same depth as in the container
- Backfill and firm gently
- Water in well and mulch lightly
- Space plants 50–80 cm apart for best effect
Propagation
- From Seed: Sow fresh seed in spring in a sandy, well-drained mix. Germination can be slow and erratic.
- From Cuttings: Take stem cuttings in late spring or early summer. Allow cut ends to dry before planting in a gritty mix. Rooting hormone may improve success.
Cultural History
Euphorbia glauca was traditionally used by Māori for medicinal purposes, though care was taken due to its toxic sap. The plant is now valued for its role in coastal restoration and as a symbol of threatened native flora.
Pests & Diseases
- Pests: Aphids and slugs may occasionally attack young shoots. Use organic controls if needed.
- Disease: Root rot is the main issue, usually caused by poor drainage or overwatering. Ensure soil is free-draining and avoid wet winter conditions.
Bonus Tip
Wear gloves when handling Euphorbia glauca to avoid skin irritation from its milky sap. Plant alongside other coastal natives for a resilient, wildlife-friendly garden.
