PL. —Leontopodium alpinumBotanical illustration — drop image
Leontopodium alpinum

Edelweiss

Summer
3a7bHardiness zone
Peak bloom windowZone 6b · frost-offset weeks
Winter
Not in bloom
Spring
Peak bloom
Summer
Peak bloom
Fall
Not in bloom
Peak bloom
In bloom
Background

Leontopodium alpinum is a compact alpine perennial native to rocky limestone slopes of the Alps and Carpathians at elevations between 1,800 and 3,400 m. Its rosettes of lance-shaped leaves and white woolly star-shaped bracts are national symbols of Austria, Switzerland, Slovenia, Bulgaria, and Italy; Romania declared it a monument of nature in 1931. Despite its reputation as rare in the wild, it grows reliably in cultivation when given the right conditions.

Sharp drainage is the single most important requirement. Edelweiss thrives in alkaline, gritty soil with low fertility and tolerates drought once established. In climates with humid summers or wet winters, crown rot is the main failure point; raised beds and rock gardens with a gravel collar around each plant significantly improve success. The plant is short-lived — typically two to four years — but self-seeds freely where conditions suit. Seeds need light to germinate and benefit from cold stratification. Preferred soil pH is 7.0–8.0; do not amend with peat or enrich with high-nitrogen fertilizer.

The dense white tomentum covering leaves and bracts has sub-micrometer fiber structure that scatters and absorbs near-ultraviolet radiation, an adaptive trait for intense high-altitude UV exposure that has attracted research interest in UV-protective materials and cosmetics. Traditional Alpine folk medicine used the plant for abdominal pain and respiratory complaints including bronchitis.

Care guide
SunFull sun
WaterLow; sharp drainage essential, drought tolerant once established
SoilLean, gritty, alkaline, very well-drained
Spacing6–8 inches
Height6–8 inches
Zone3a – 7b
Direct sowFrost hardy
Seasonal tasks
winter
sowSurface-sow seeds indoors on moist gritty mix — do not cover; seeds need light to germinate. Place the tray in a sealed bag and cold-stratify in the refrigerator at 35–40°F for 3–4 weeks before moving to a bright, cool windowsill.
spring
sowOnce seedlings have two true leaves, prick out into individual 2 in pots filled with gritty, low-fertility mix. Grow on in a cool, bright location — avoid warmth and shade, which produce weak, floppy growth.
sowHarden off plants for one to two weeks, then transplant into a rock garden or raised bed in gritty alkaline soil after last frost. Set plants at the same depth as in the pot; do not bury the crown.
summer
watchDuring wet summer spells, check the base of plants for soft, discolored tissue indicating crown rot. Improve air circulation by removing any dense surrounding vegetation and scratch a layer of fine gravel around each crown.
cutRemove spent flowering stems at the base once the woolly bracts dry and fade. This directs energy into basal rosette development and can extend the plant's life by a season.
fall
watchAllow some seed heads to mature fully if naturalizing in a rock garden. Collect dry seed heads for cold stratification and sowing the following winter.
watchBefore hard frost, top-dress around crowns with coarse grit or fine gravel — not bark or leaf mulch — to shed winter moisture away from the crown and prevent rot.
Common problems

Crown Rot

Symptoms

Lower leaves yellow and wilt; the base of the rosette turns brown and soft, sometimes with white fungal threads at the soil line. Plants collapse in wet conditions.

Treatment

Remove and destroy affected plants. Improve drainage and avoid overhead watering. Do not mulch directly against the crown. Space plants for airflow and avoid replanting in the same wet spot.

Damping Off

Symptoms

Seedlings collapse at the soil line with thin, water-soaked stems; seeds may fail to emerge or rot before sprouting.

Treatment

Sow in well-draining mix, avoid overwatering, and ensure good airflow. Remove affected seedlings and let the surface dry between waterings.

Powdery mildew

Symptoms

White or grey powdery coating on leaves — usually starting on older growth in humid conditions or when nights cool.

Treatment

Improve air circulation by thinning plants. Apply neem oil or potassium bicarbonate spray at first sign. Avoid overhead watering.

Botrytis (grey mould)

Symptoms

Grey fuzzy mould on petals and stems, worst in cool wet conditions.

Treatment

Remove affected parts immediately. Improve air circulation. Avoid overhead watering. Apply copper fungicide if severe.

From the field journal