At a Glance
TypePerennial
HabitMounding
FoliageSemi-evergreen
Height4-8 inches (10-20 cm)
Width8-12 inches (20-30 cm)
Maturity2 years
Key Features
Maintenancelow
Overview
Primula acaulis (syn. P. vulgaris) is a semi-evergreen perennial in the Primulaceae family, forming basal rosettes of crinkled, tongue-shaped leaves 4–8 inches (10–20 cm) long and 1.5–2.5 inches (4–6 cm) wide with prominent veining and a rough-textured upper surface. Plants grow 4–8 inches (10–20 cm) tall and 8–12 inches (20–30 cm) wide. Individual flowers are 1–1.5 inches (2.5–4 cm) across, five-petalled with a notched apex, borne on short individual pedicels 2–4 inches (5–10 cm) long arising directly from the crown — distinguishing it from polyanthus types (P. x polyantha) which bear flowers in umbels on a common stalk. Wild-type flower colour is pale yellow with a darker yellow centre; cultivated forms span white, yellow, pink, red, purple, blue, and orange. Heterostyly (pin and thrum flower morphs) is present, requiring cross-pollination between the two forms for seed set. In the Pacific Northwest, bloom begins in late January to February in mild winters and continues through April. Foliage may become semi-dormant and tattered in summer heat above 80°F (27°C) but recovers with autumn rain. Susceptible to vine weevil larvae (root damage), slugs, and botrytis in wet, poorly ventilated conditions. Short-lived in hot, humid climates — performs as a cool-season annual south of USDA zone 8.
Native Range
Primula acaulis is native across western and southern Europe, from the British Isles and Scandinavia south through the Iberian Peninsula, the Mediterranean, and east to the Caucasus and Turkey. It occurs in deciduous woodland margins, hedge banks, meadows, and grasslands from sea level to approximately 6,500 feet (2,000 m).Suggested Uses
Planted in woodland gardens, shaded borders, and beneath deciduous trees and shrubs, spaced 8–10 inches (20–25 cm) apart for a continuous carpet in spring. Effective in containers (minimum 2 gallons / 7.5 L) for winter-spring colour on porches and patios. Naturalises in moist, semi-shaded lawns and meadows where grass is not mown before May.How to Identify
Appearance
Size & Dimensions
Height4" - 8"
Width/Spread8" - 1'
Reaches mature size in approximately 2 years
Bloom Information
In the Pacific Northwest, flowering begins as early as late January in mild winters, with peak bloom from February through April. Individual flowers last 2–3 weeks. The total bloom period spans 6–10 weeks. A sporadic second flush may occur in cool, moist autumn weather. Pollinated by long-tongued bumblebees and bee flies (Bombylius major).Detailed Descriptions
Flower Description
Pale yellow with darker centre (wild type); wide colour range in cultivarsFoliage Description
Medium to dark greenGrowing Conditions
Sun Requirements
Requires 3-6 hours of direct sunlight daily
• Full Sun: 6+ hours of direct sunlight
• Partial Shade: 3-6 hours of direct sunlight
• Full Shade: Less than 3 hours of direct sunlight
Care & Maintenance
Care Guide
Plant in partial shade in humus-rich, moist but well-drained soil with a pH of 5.5–7.0. Space 8–10 inches (20–25 cm) apart. In the Pacific Northwest, morning sun with afternoon shade is optimal — full sun causes leaf scorch and premature dormancy in summer. Water regularly through the growing season; do not allow the root zone to dry completely. Mulch with 1–2 inches (2.5–5 cm) of leaf mould or composted bark to maintain cool, moist soil. Divide congested clumps every 3–4 years immediately after flowering to maintain vigour. Feed with a balanced liquid fertiliser in early spring as flower buds develop.Pruning
Remove spent flower stalks at the base after bloom to tidy appearance and prevent self-seeding (unless naturalisation is desired). Cut back tattered summer foliage in late autumn; fresh leaves will emerge with autumn rain. No other pruning is required.Pruning Schedule
J
F
M
A
M
J
J
A
S
O
N
D
late spring
Maintenance Level
lowContainer Growing
✓ Suitable for container growing
Minimum container size: 2 gallons