Chalk milkwort
Polygala calcarea · Polygalaceae
The gardener's calendar
Ideal time to plant chalk milkwort: set it out when the soil is neither frozen nor waterlogged, and water generously as it establishes.
ID card
- Foliage
- Evergreen
- Flowering
- April to June
- Adult size
- 15 to 30 cm in height
- Hardiness
- Hardy, down to -15°C
- Exposure
- Sun to partial shade
- Soil
- Calcareous, well-drained
- Growth
- Slow to moderate
- Origin
- Western Europe
Care
Exposure
Chalk Milkwort prefers a sunny to partially shaded position. Full sun exposure promotes more generous flowering and a more compact habit. Avoid overly shaded areas that would slow its growth and reduce flower production.
Soil and drainage
This plant particularly enjoys calcareous soils, hence its common name. Excellent drainage is essential; incorporate gravel or coarse sand if the soil tends to retain moisture. Poor to moderately fertile soil suits this small alpine shrub perfectly.
Watering
Water moderately during the growing period, allowing the soil to dry slightly between waterings. In winter, considerably reduce water intake as the plant enters its dormant phase. Be careful not to create waterlogging that could rot the roots.
Pruning and shaping
Light pruning after flowering (June-July) helps maintain a compact, bushy habit. Remove dead or damaged branches as the plant emerges from winter. This plant does not require severe pruning and should retain its natural form.
Fertilizer
A very modest application of balanced fertilizer in spring is quite sufficient. This small alpine plant thrives naturally in poor soil; over-enrichment would promote excessive growth at the expense of flowering. Avoid nitrogen-rich fertilizers.
Health and prevention
Chalk Milkwort is generally robust. Watch for powdery mildew in overly humid and confined situations, especially if drainage is not optimal. Good air circulation and well-draining soil prevent most fungal issues. No major pests usually affect it.
Did you know?
The genus Polygala encompasses more than 500 species worldwide, and its name means 'much milk' in Greek, referring to an old belief that the plant would increase milk production in animals that consumed it. Chalk Milkwort, as a small European alpine species, is prized in rock gardens and botanical collections for its delicate blue-violet flowers and its remarkable affinity for calcareous soils.
Where to buy it
Plant in spring or early autumn, avoiding spells of intense heat. Pick a plant with healthy foliage and roots that are not exposed. Best time: March, April, May, September.
Add this plant to my garden →Plants from the same family
- Common milkwortPolygala vulgaris
- Polygala serpyllifoliaPolygala serpyllifolia
- Polygaloides chamaebuxusPolygaloides chamaebuxus
- Tufted milkwortPolygala comosa
- Polygala amarellaPolygala amarella
- Myrtle-leaved milkwortPolygala myrtifolia
Tips generated and checked by Viridia — adapt them to your local climate.