Celmisia sessiliflora
Cotton Daisy, also known as White Cushion Mountain Daisy, is a remarkable and compact endemic New Zealand alpine plant that forms robust, densely branched subshrubs creating impressive dense patches up to 1 meter in diameter and 100mm tall, featuring distinctive linear leaves measuring 10-30mm long covered in dense white appressed hairs that create a silvery-grey cushion effect topped with charming sessile white daisy flowers measuring 10-20mm diameter that bloom from October to February. This specialized alpine cushion plant thrives throughout the South Island from Nelson south to Southland in montane to alpine environments, colonizing grasslands, herbfields, and fellfields, and sometimes establishing on challenging rock outcrops where its slow-growing, low sessile habit and wind-dispersed seeds allow it to form very tight cushions that survive harsh mountain conditions. With its adaptation to extreme alpine environments, ability to form spectacular silvery mounds dotted with almost stalkless white flowers, and availability from specialized alpine nurseries for dedicated mountain gardeners, this challenging but rewarding species makes an outstanding choice for alpine houses, south-facing rockeries, and specialized mountain plant collections where its distinctive cushion growth habit and resilient beauty can showcase the remarkable adaptations of New Zealand's high-country flora. alpine plants
Image credit: Cotton Daisy (Celmisia sessiliflora). Wikipedia
| Scientific Name | Celmisia sessiliflora |
|---|---|
| Height | Up to 10cm (low cushion form) |
| Spread | Up to 1 meter diameter (dense patches) |
| Water Needs | Moderate (moist but well-draining) |
| Light | Full sun (alpine conditions) |
| Frost Tolerance | Excellent (high alpine native) |
| Salt Tolerance | Poor (montane species) |
| Growth Rate | Very slow (alpine cushion plant) |
| Lifespan | Very long-lived perennial |
Cotton Daisy thrives in cool, alpine conditions with excellent drainage and protection from heat and humidity. It requires specialized growing conditions that mimic its natural high-altitude mountain habitat.
| City | Climate Suitability |
|---|---|
| Whangārei | Poor (too warm and humid) |
| Auckland | Poor (too warm and humid) |
| Hamilton | Poor (too warm and humid) |
| Tauranga | Poor (too warm and humid) |
| Rotorua | Moderate (cooler highland) |
| Gisborne | Poor (too warm) |
| New Plymouth | Moderate (alpine house only) |
| Napier | Poor (too warm and dry) |
| Whanganui | Moderate (alpine house) |
| Palmerston North | Moderate (alpine house) |
| Wellington | Good (cooler, windy) |
| Nelson | Good (natural range) |
| Christchurch | Ideal (cool, dry climate) |
| Dunedin | Ideal (cool climate) |
| Invercargill | Ideal (natural range) |
Cotton Daisy has specific alpine soil preferences:
High alpine light conditions:
Moderate moisture with perfect drainage:
Cotton Daisy requires absolutely minimal maintenance:
The tight silvery cushion growth habit and sessile white flowers are the main attractions and should never be disturbed - this plant's beauty lies in its natural form.
The best time to plant Cotton Daisy is during spring when active growth begins, though this challenging alpine specialist requires very careful timing and preparation.
Choose a site with:
Maintain perfect drainage while preventing complete drought. Provide cool conditions and excellent air circulation. This is one of the most challenging New Zealand alpine plants to cultivate successfully.
Growing from seed is the primary method (though difficult):
Cuttings are possible but extremely challenging:
Occasionally available from specialized alpine nurseries and seed suppliers. Best suited to experienced alpine gardeners with proper facilities.
Cotton Daisy (Celmisia sessiliflora) represents both the remarkable cushion plant adaptations of New Zealand's alpine flora and the specialized strategies required for survival in extreme mountain environments:
Today, Cotton Daisy serves as the ultimate challenge for alpine gardening enthusiasts, representing both the extraordinary adaptations of New Zealand's high-country flora and the specialized cultivation skills required to grow extreme alpine plants successfully.
Provide perfect drainage, cool conditions, and excellent air circulation. This species is only suitable for dedicated alpine specialists with proper facilities. Most problems stem from attempting cultivation in non-alpine conditions.
Cotton Daisy is the ultimate alpine gardener's challenge - this spectacular cushion plant creates tight silvery mounds up to a meter across dotted with almost stalkless white daisy flowers, but it's also one of New Zealand's most difficult plants to grow! The key is understanding it's a true high-alpine specialist that needs perfect drainage, cool conditions, and absolutely no humidity. Think "mountain scree" conditions - never wet, never completely dry, always cool with excellent air circulation. Best grown in an alpine house or very specialized south-facing rockery. The reward for success is having one of the most remarkable cushion plants in the world - but be prepared for the challenge! This is definitely not a plant for beginners, but for experienced alpine growers, it's the holy grail of New Zealand mountain plants.
Pair compact celmisias with cushion plants to build resilient, fine‑textured alpine plantings that thrive in high light and free‑draining soils.
Learn more about New Zealand's mountain flora in Alpine Plants.
Celmisia sessiliflora forms neat clumps of narrow, often silvery leaves with flower stalks bearing white daisies close to the foliage (“sessile” appearance). Compact habit suits small alpine beds and troughs.
Subalpine to alpine grasslands and rocky knolls with sharp drainage, high light, and cool air movement. Often with tussocks and other rosette herbs.
Low rosettes shed water and resist wind; reflective leaf surfaces help reduce heat load. Flowers provide resources for alpine pollinators during short growing seasons.
Stabilises thin soils and adds nectar resources in high‑country plantings. Pairs with cushion plants to increase habitat diversity near ground level.
Grow in raised beds, scree gardens, or containers with alpine mixes. Mulch with grit around rosettes and water sparingly in summer heat.
Deadhead to prolong display; remove old leaves annually. Divide congested clumps in early spring and replant into fresh, gritty mix.
Best in rock gardens, troughs, and raised planters. Combine with Raoulia and small tussocks for fine‑scaled alpine compositions.
Generally not threatened. Use eco‑sourced plants in high‑country restoration and protect vulnerable sites from trampling. Avoid artificial enrichment that favours weeds at the expense of alpine specialists.
Celmisia (tikumu) hold cultural importance and today are celebrated in alpine gardens for resilience and striking foliage. Use eco‑sourced plants in restoration and avoid collecting from the wild.
