PL. —Armeria maritimaBotanical illustration — drop image
Armeria maritima

Sea Thrift

SpringSummer
3a9bHardiness zone
Peak bloom windowZone 6b · frost-offset weeks
Winter
Peak bloom
Spring
Peak bloom
Summer
Not in bloom
Fall
Not in bloom
Peak bloom
In bloom
Background

Armeria maritima is a compact evergreen perennial native to coastal cliffs, salt marshes, and rocky shorelines across Europe and North America. It forms tight, grass-like mounds and sends up slender stems topped with dense globe-shaped heads of pink flowers in late spring and early summer. Its salt tolerance, drought resistance, and tidy habit make it well suited to rock gardens, border edges, and xeriscape plantings.

Excellent drainage is essential; the plant rots in heavy or consistently wet soil. Low fertility suits it best — rich soil favors leafy growth over flowering. Avoid mulching around the crown. It tolerates a pH of 6.0–7.0 and thrives in poor, sandy, or gravelly soils. Clumps may die out in the center after several years; divide in early spring to rejuvenate them. Cold-hardy to zone 3 and highly tolerant of salt spray and wind, making it a reliable choice for coastal and exposed sites.

Armeria maritima has a documented history of folk medicinal use in parts of Europe, recorded for external antiseptic application and for urinary and thyroid complaints. The plant contains plumbagic acid and armericin, compounds that have been studied for antimicrobial activity.

Care guide
SunFull sun
WaterLow
SoilSandy, well-drained, low fertility
Spacing9–12 in
Height6–12 in
Zone3a – 9b
Native RegionAK, CA, OR, WA
Direct sowFrost hardy
Seasonal tasks
winter
sowStart seeds indoors in a well-drained, gritty mix 8–10 weeks before last frost. Press seeds onto the surface; they need light to germinate.
spring
sowDivide established clumps in early spring before new growth begins. Replant vigorous outer sections in refreshed, gritty, well-drained soil.
sowTransplant seedlings or nursery starts into sandy, well-drained soil in full sun at or just after the last frost date.
summer
watchCheck clump centers for die-back during hot, humid periods. Congested or wet centers rot; remove dead material and improve drainage around the crown.
cutRemove spent flower stems at the base after the main flowering flush to keep clumps tidy and encourage repeat blooming.
fall
watchInspect foliage for rust pustules or crown rot as moisture increases in fall. Remove affected material promptly and avoid overhead watering.
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.

Rust

Symptoms

Orange to brown raised pustules on the undersides of leaves, with yellow spotting on the upper surface. Heavy infections cause leaves to yellow and drop.

Treatment

Remove and destroy infected leaves. Avoid overhead watering and improve air circulation. Apply a sulfur or copper-based fungicide if it spreads. Clear plant debris in fall.

Phytophthora Root Rot

Symptoms

Wilting despite moist soil, yellowing leaves, stunted growth, and dark, decayed roots and crown tissue. Vines may collapse during hot weather.

Treatment

Plant in well-draining soil and avoid waterlogging. Remove and destroy affected vines. Improve drainage with raised beds or amended soil and avoid overwatering.