Polygala × dalmaisiana

Common Name: sweet pea shrub 
Type: Broadleaf evergreen
Family: Polygalaceae
Native Range: Garden origin
Zone: 9 to 11
Height: 3.00 to 5.00 feet
Spread: 3.00 to 5.00 feet
Bloom Time: Seasonal bloomer
Bloom Description: Rose-magenta flowers with white-purple crest
Sun: Full sun to part shade
Water: Medium
Maintenance: Medium
Suggested Use: Hedge
Flower: Showy
Leaf: Evergreen
Attracts: Hummingbirds
Other: Winter Interest
Tolerate: Deer


Winter hardy to USDA Zones 9-11 where it is best grown in evenly moist but well-drained soils in full sun to part shade. Best planted in a sheltered location. Tolerates minimum temperatures which briefly drop into the mid 20’s F. in winter, but best growth and flowering occur in frost free climates.

Noteworthy Characteristics

Polygala of the milkwort family is a genus featuring over 500 species of plants (annuals, herbaceous perennials, subshrubs and shrubs) which are widely distributed in warm to temperate regions throughout the world. Plants are generally noted for having alternate lanceolate leaves and pea-like often showy flowers in terminal clusters/racemes.

Polygala x dalmaisiana, commonly called sweet pea bush or milkwort, is a loose, leggy, fast-growing, rounded to spreading, bushy evergreen shrub which typically grows to 3-5’ tall and as wide. It is reportedly a hybrid between two South African species (P. opposistifolia and P. myrtifolia). Stems are clad with ovate dull green leaves (1” long). Terminal racemes of rose-magenta pea-like flowers with two winged petals surrounding a white purple crest bloom summer to frost, but bloom extends to almost year round in mild frost-free climates with minimum temperatures of 40°F. Flowers resemble those of sweet pea.

Genus name comes from the Greek words polys meaning much and gala meaning milk in reference to a belief dating back to the medieval era that ingestion of plant leaves by certain nursing mammals resulted in increased milk production.

Hybrid name honors a French gardener by the name of Dalmais who reportedly raised this plant from seed in 1839.


No serious insect or disease problems. Aphids and whiteflies may appear.


Group or mass in shrub borders. Hedge. Rock garden. Cottage gardens. Courtyard gardens. Patio containers. Good cut flower for flower arrangements.