How to Grow Persian Violet — Exacum

Sharing is caring!

Exacum–commonly called Persian violet–is an evergreen subtropical perennial usually grown as an annual. Exacum bears violet to blue, occasionally pink or white flowers with conspicuous yellow stamens. Flowers appear on 4-angled stems above lance-shaped mid-green leaves.

Exacum can be grown as summer-flowering annuals in beds and borders in subtropical regions. It is grown as a houseplant in temperate regions.

Exacum needs well-drained soil. It grows well in full sun outdoors. It needs full light indoors.

Exacum is a genus of about 25 species of annuals and perennials native to stream banks from Yemen to India. One species, Exacum affine, is commonly grown in gardens and as a houseplant.

Get to know Exacum

  • Plant type: Tropical annual, short-lived perennial
  • Growing zones and range: Zones 11-12
  • Hardiness: Tender
  • Height and width: 9 to 12 inches (23-30cm) tall
  • Foliage: Leaves are light green, oval, waxy to 1 inch long
  • Flowers: Small fragrant, star-shaped flowers are white, blue, or lravender with yellow eyes and stamens.
  • Bloom time: Fall and winter
  • Uses: Bed and borders in tropical regions, houseplant
  • Common name: Persian violet
  • Botanical name: Exacum
  • Family name: Gentianaceae
  • Origin: Near streams from Yemen to India
White Persian Violet, Exacum affine 'White Midget'
White Persian Violet, Exacum affine ‘White Midget’

Where to plant Exacum

  • Light outdoors: Outdoors grow Exacum in full sun.
  • Light indoors: Grow Exacum in full light.
  • Soil outdoors: Plant Exacum in moderately fertile, welld-drained soil.
  • Soil indoors: Grow in a soil-based potting mix with added sharp sand.

When to plant Exacum

  • Sow seed outdoors in early spring.

Planting and spacing Exacum

  • Space Exacum 9 to 12 inches (23-30cm apart.

How to water and feed Exacum

  • Water Exacum freely during the growing season; water sparingly in winter.
  • Fertilize Exacum with a balance liquid fertilizer every 2 to 3 weeks.

Exacum care

  • To extend Exacum’s blooming period, remove the flowers as they fade.
  • After the plant has finished flowering, it will die and can be discarded.

Growing Exacum as a houseplant

  • Grow Exacum in a warm room with bright light and high humidity.
  • Use an extra rich growing medium and keep it evenly moist at all times.
  • Fertilize exacum every two week.

Exacum pests and diseases

  • Exacum is not prone to attack by insects.
  • Exacum can suffer from botrytis blight, neucrotic spot birus, canker, and root rot.

Exacum propagation

  • Propagate Exacum from seed sown in the spring for fall and winter bloom, or from stem cuttings taken before the plant is discarded.

Exacum varieties to grow

  • Exacum affine, Persian violet. Grows 9 to 12 inches tall and wide; 4-angled stems and ovate to elliptic shiny leaves; bears scneted, lavender-blue, rose-pink, or white flowers with conspicuous yellow stames. Cultivars include: ‘Blue Gem’ compact to 8 inches tall with lavender-blue flowers, ‘Blue Midget’ to 5 inches tall with lavender-blue flowers; ‘White Midget’ to 5 inches tall with white flowers.

Written by Stephen Albert

Stephen Albert is a horticulturist, master gardener, and certified nurseryman who has taught at the University of California for more than 25 years. He holds graduate degrees from the University of California and the University of Iowa. His books include Vegetable Garden Grower’s Guide, Vegetable Garden Almanac & Planner, Tomato Grower’s Answer Book, and Kitchen Garden Grower’s Guide. His Vegetable Garden Grower’s Masterclass is available online. has more than 10 million visitors each year.

How To Grow Tips

How To Grow Tomatoes

How To Grow Peppers

How To Grow Broccoli

How To Grow Carrots

How To Grow Beans

How To Grow Corn

How To Grow Peas

How To Grow Lettuce

How To Grow Cucumbers

How To Grow Zucchini and Summer Squash

How To Grow Onions

How To Grow Potatoes

How to Grow Flame Violet — Episcia

How to Grow Flame Lily — Gloriosa