Nemesia caerulea
Common Name: nemesia 
Type: Herbaceous perennial
Family: Scrophulariaceae
Native Range: Temperate southern Africa
Zone: 9 to 10
Height: 1.00 to 2.00 feet
Spread: 0.75 to 1.50 feet
Bloom Time: June to frost
Bloom Description: Pale blue, pink or white with yellow throat
Sun: Full sun to part shade
Water: Medium
Maintenance: Medium
Suggested Use: Annual
Flower: Showy


Tender perennial that is winter hardy to USDA Zones 9-10. In St. Louis, it is grown as a cool weather annual in humusy, evenly moist, well-drained soils in full sun to part shade. Best performance is in full sun, however these cool weather lovers will bloom longer into the hot St. Louis summer if given some part afternoon shade. When plants do succumb to the hot weather, cut them back for a possible fall bloom or remove them from the garden. Start seeds indoors 8-10 weeks before last frost date or purchase starter plants. Set out seedlings/starter plants at last frost date. Seed should not be sown directly in the ground in spring in the St. Louis climate.

Noteworthy Characteristics

Nemesia caerulea is native to South Africa and typically grows to 2’ tall on erect to spreading stems. Two-lipped, tubular, almost lobelia-like flowers in lavender, pale blue, pink and white with yellow throats bloom spring to fall in northern cool summer climates, but spring to early summer in St. Louis. Lance-shaped green leaves (to 1.5” long). Synonymous with N. fruiticans and N. foetens.

Genus name comes from the Greek name nemesion for a similar plant.

Specific epithet means dark blue.


No serious insect or disease problems. Root rot may occur in poorly drained soils.


Beds, mixed borders, rock gardens or containers.