Chatham Island Forget-Me-Not
Myosotidium hortensia
The Chatham Island Forget-me-not (scientific name: Myosotidium hortensia ) is one of New Zealand's most spectacular and iconic native plants. Endemic to the Chatham Islands, this giant perennial herb is famous for its massive, glossy green leaves and vibrant clusters of blue flowers that resemble traditional forget-me-nots on a much larger scale. Known to Māori as Kopakopa or Kopukapuka, it holds a unique place in New Zealand's botanical heritage. This guide explores the fascinating characteristics and specific requirements of this coastal specialist, which has become a highly prized addition to temperate gardens worldwide, supporting conservation efforts for Native Flowers .
Plant Description
Myosotidium hortensia is a robust, evergreen perennial herb that forms large, impressive clumps. Its most striking feature is its foliage; the leaves are massive, circular to heart-shaped, and can reach up to 40 centimetres across. These leaves are thick, leathery, and deeply veined with a lustrous, glossy green surface that reflects light beautifully. In late spring and early summer, typically from September to November, the plant produces large, terminal clusters of flowers. These blooms are usually a brilliant, deep blue, though they can range to pale blue or occasionally white. Each individual flower is about 1 to 1.5 centimetres in diameter, held in dense cymes that can be 10 to 20 centimetres across. The plant typically grows to a height of 60 centimetres to 1 metre, with a similar spread, creating a dramatic architectural presence in the landscape.
Quick Facts
| Scientific Name | Myosotidium hortensia |
|---|---|
| Height | 0.6-1.0 metres |
| Spread | 1.0-1.5 metres |
| Water Needs | High (Keep moist) |
| Light | Partial Shade |
| Frost Tolerance | Half-hardy |
| Salt Tolerance | High |
| Growth Rate | Medium |
| Lifespan | 5-10 years |
Climate Best Suited to
The Chatham Island Forget-me-not thrives in cool, maritime climates. It is best suited to coastal regions where the air is humid and temperatures are moderated by the sea. In New Zealand, it grows exceptionally well in the southern regions and coastal areas of both the North and South Islands. It does not enjoy extreme heat or prolonged dry periods, as its large leaves lose moisture rapidly. In warmer northern climates, it must be planted in a cool, shaded spot to prevent wilting and heat stress.
Regional Suitability
| City | Climate Suitability |
|---|---|
| Auckland | Moderate (Requires shade) |
| Wellington | Excellent |
| Christchurch | Good (Requires shelter) |
| Dunedin | Excellent |
| Invercargill | Excellent |
Plant Habitat
In its natural state, Myosotidium hortensia is found exclusively on the Chatham Islands. Its habitat includes coastal cliffs, rock outcrops, and the rear of boulder beaches, often just above the high-tide mark. It has a remarkable ability to grow in environments directly influenced by salt spray and sea winds. Interestingly, it is often found growing among kelp drift and accumulated paua shells, which provide rich nutrients. It also occurs in openings within coastal forests where light is filtered and the ground remains moist.
Plant Conservation
Currently classified as "At Risk - Declining," the Chatham Island Forget-me-not faces several significant threats in the wild. Its populations have been severely impacted by farming activities, habitat loss, and competition from invasive plants like marram grass. Feral animals, including cattle, sheep, and pigs, pose a major threat by trampling and browsing the plants. Additionally, rodents and weka often prey on the seeds and flowers. Conservation efforts focus on habitat protection, predator control, and the establishment of "insurance" populations in cultivation.
Growing Requirements
Soil Requirements
Prefers deep, rich, humus-heavy soil that mimics its natural nutrient-rich coastal environment.
- Well-drained but moisture-retentive
- Rich in organic matter or seaweed
- Slightly acidic to neutral pH
Light Requirements
Best in partial shade, especially in the afternoon. Needs protection from intense direct sunlight.
- Filtered light or dappled shade
- Morning sun with afternoon shade
- Avoid hot, dry, exposed sites
Water Requirements
Requires consistent moisture. The large leaves transpire heavily and will wilt quickly if dry.
- Regular, deep watering
- High humidity is beneficial
- Do not allow to dry out completely
Planting Guide
When planting Myosotidium hortensia , choose a sheltered spot that stays cool. Dig a hole twice the width of the root ball and enrich it with plenty of compost and, if available, some aged seaweed to replicate its natural diet. Ensure the plant is placed at the same depth as it was in its container. Mulch heavily with organic material or even crushed seashells to help retain moisture and keep the roots cool. If planting in a group, space them about 1 metre apart to allow for their significant spread.
Ecological Role
As a specialist of the Chatham Island coastline, Myosotidium hortensia plays a vital role in stabilizing coastal margins. Its large leaves provide shelter and a humid microclimate for smaller ground-dwelling invertebrates. The flowers are an important source of nectar for native insects, including moths and flies, which are the primary pollinators in its isolated island home. By trapping wind-blown organic matter and salt spray, it contributes to the accumulation of nutrient-rich soil in rocky coastal environments.
Uses & Significance
Garden Uses
An outstanding specimen plant for shady borders, woodland gardens, or cool coastal landscapes.
- Dramatic architectural focal point
- Mass planting for high-impact ground cover
- Excellent for pots in cool, shaded courtyards
Highly valued by the people of the Chatham Islands and Māori as a symbol of their unique island home.
- Symbolic of Chatham Island (Rēkohu) identity
- Known as Kopakopa in Te Reo Māori
- Prized as a heritage plant in New Zealand gardens
Ecological Value
Supports the unique biodiversity of the Chatham Islands and provides food for native pollinators.
- Nectar source for native insects
- Provides habitat for coastal invertebrates
- Key species for Chatham Island restoration projects
Cultural Significance
While specific records are limited for this species, Myosotidium hortensia sits within a wider native plant tradition valued for its ecological role and local stewardship.
Landscaping Uses
In landscaping, the Chatham Island Forget-me-not is used to create a lush, tropical feel in temperate gardens. Its bold texture contrasts beautifully with finer-foliaged native ferns and grasses. It is particularly effective when planted alongside water features or in the cool, damp areas of a garden where other plants might struggle. In coastal gardens, it provides a spectacular flowering display that is both resilient to salt and visually stunning.
Seasonal Care Calendar
Spring
This is the peak flowering season and a time of rapid growth.
- Apply a balanced organic fertiliser
- Ensure consistent watering as flowers emerge
- Watch for slugs and snails
Summer
Focus on moisture retention during the hottest months.
- Maintain a thick layer of mulch
- Water deeply during dry spells
- Provide extra shade if wilting occurs
Autumn
A time for tidying up and preparing for the cooler months.
- Remove spent flower heads (deadheading)
- Clear away any dead or damaged leaves
- Collect ripe seeds for propagation
Winter
The plant enters a period of slower growth.
- Protect young plants from heavy frost
- Reduced watering but do not let dry out
- General garden cleanup around the base
When to Prune and How Much
Myosotidium hortensia does not require heavy pruning, but regular grooming keeps it looking its best.
- Deadhead spent flowers to encourage tidiness
- Remove yellowing or tattered leaves at the base
- Cut back old foliage in late winter to refresh the plant
Avoid cutting into the main crown of the plant. Simply snip the stems of dead leaves and flowers as close to the base as possible without damaging the new growth emerging from the centre.
How to Grow Chatham Island Forget-Me-Not (Kopakopa)
Growing the Chatham Island Forget-me-not ( Myosotidium hortensia ) can be a rewarding challenge for any gardener. This spectacular plant requires a bit of extra attention to thrive, but its giant leaves and blue flowers are well worth the effort. The most important thing to remember is that this is a maritime plant; it loves cool, humid air and rich, moist soil. If you live in a hot or dry area, you must provide a cool, shaded microclimate for it. Traditionally, many New Zealand gardeners have found success by feeding the plant with liquid seaweed or even placing fresh seaweed around the base, as this provides the minerals and salts the plant enjoys in its natural Chatham Island home. Be vigilant with slug and snail protection, as they can quickly ruin the beautiful glossy leaves.
From Seed
Seeds are the most common way to propagate this species. They should be sown as fresh as possible for the best results.
- Collect the dark, winged seed capsules in late summer or autumn.
- Sow seeds on the surface of a seed-raising mix and cover lightly.
- Keep the tray in a cool, shaded spot and maintain consistent moisture.
- Germination can be slow and irregular, often taking several months.
Once seedlings have several leaves, transplant them carefully into individual pots, taking care not to disturb the roots too much.
From Cuttings
While less common, it is possible to grow new plants from offsets or divisions of the main crown.
- In late winter or early spring, identify small side-crowns or offsets.
- Carefully separate these from the main plant using a sharp, clean knife.
- Ensure each division has some roots attached.
- Pot up into a rich, well-draining mix and keep very moist until established.
Additional Methods
Self-seeding is common in the garden if the conditions are right and the ground is left undisturbed.
- Allow some flower heads to go to seed and drop naturally.
- Look for small seedlings emerging around the base of the parent plant.
- Carefully lift and relocate these volunteers to new spots.
Pests & Diseases
The biggest threat to the appearance of Myosotidium hortensia is slugs and snails, which find the large, succulent leaves irresistible. Regular monitoring and the use of bird-friendly baits or copper barriers are often necessary. Aphids can sometimes affect the new flower buds. In terms of diseases, the plant is relatively robust but can suffer from crown rot if the soil is waterlogged or the drainage is poor. Leaf spot can occur in very humid conditions with poor air circulation; removing affected leaves usually solves the problem.
Bonus Tip
For truly spectacular leaves, try "feeding" your plant with a few handfuls of crushed paua shells or aged seaweed. This mimics its natural environment and provides the specific trace elements that help produce that incredible glossy sheen.
Related Plants
Other Chatham Islands endemic plants and coastal species.
