Native to the western Mediterranean, this tender evergreen perennial is commonly grown as an annual in temperate climates. It forms a clump of stems bearing narrow, dark green to reddish bronze leaves with toothed margins, and large flower heads over a long bloom time. Each flower head is dome-shaped, four to five inches wide, and made up of clusters of tiny star-shaped flowers in blue-violet, pink, white, or mauve. Flowering starts in the summer and continues into fall if plants are deadheaded. The flower heads are slightly fragrant, attractive to bees and butterflies, and make excellent cut flowers, lasting up to two weeks in the vase. Blue throatwort is a good choice for use in beds, borders, and containers. The generic name, Trachelium, comes from the Greek word for neck and refers the use of the plant to treat problems of the throat. Regular and dwarf cultivars are available.
Type: Herbaceous, evergreen tender perennial
Bloom: Clusters of tiny blue-violet star-shaped flowers are borne in dome shaped flowerheads from summer into fall
Size: 2.3′ H x 2-3′ W
Light: Full sun
Soil: Average, moist, well-drained, slightly acidid
Care: Deadhead to extend bloom time
Hardiness: Zones 9-10
Pests and Diseases: None of significance but susceptible to aphids and mites
Propagation: Seed, stem cuttings
Companion Plants: Lilies, gladiola, yarrow (Achillea ‘Anthea’), red New Zealand flax (Phormium), Mexian bush sage (Salvia leucantha), pink muhly grass (Pennisetum glaucum), Fragaria vesca ‘Golden Alexandra’, blue catmint (Nepeta faassenii), Artemisa ‘Powis Castle’.