Eustoma grandiflorum
Common Name: lisianthus 
Type: Herbaceous perennial
Family: Gentianaceae
Native Range: Nebraska, Colorado, Kansas, Texas
Zone: 8 to 10
Height: 1.00 to 3.00 feet
Spread: 0.75 to 1.00 feet
Bloom Time: June to frost
Bloom Description: Pale purple
Sun: Full sun
Water: Medium
Maintenance: High
Suggested Use: Annual
Flower: Showy

Culture

Biennial that will survive winters in USDA Zones 8-10. In St. Louis, it is grown as an annual. It is easily grown in average, uniformly moist, well-drained soils in full sun. Growing from seed can be rather difficult because the seed is dust particle size and it takes about 5 months from planting to first bloom, all of which basically precludes direct sowing in the ground in spring. If grown from seed, start seed indoors at least 10-12 weeks before last frost date. Set seedlings or purchased plants out after last frost date. Pinch young plants to encourage branching.

Noteworthy Characteristics

Eustoma grandiflorum, commonly called prairie gentian, bluebell gentian or lisianthus, is native to prairies and fields from northern Mexico north to Colorado and Nebraska. It is a biennial or annual that grows on erect single to sometimes branching stems rising to 3’ tall. Large gentian-like bell-shaped flowers (to 2” across) with flaring pale purple petal-like lobes bloom in summer from the upper leaf axils. Garden cultivars typically grow 18-30” tall, although some dwarf varieties (to 6-8” tall) are available. Additionally, cultivars offer a broader range of flower colors including various shades of pink, blue-violet and white. Some double-flowered varieties are also available. Ovate to oblong, 3-5 veined, stem-clasping, gray-green leaves (to 3” long). Excellent cut flower. Synonymous with Lisianthus russellianus.

Genus name comes from the Greek words eu meaning good and stoma meaning a mouth or a pretty face, a reference B592to the showy flowers.

Specific epithet means large flowers.

Problems

No serious insect or disease problems. Some susceptibility to viruses and stem cankers.

Uses

Beds, borders, cutting gardens. Dwarf plants do well in pots/containers for patios/decks or as houseplants.