Propagate by seed, cuttings, division or separation - Cuttings are usually more successful than division.

Take softwood or semi-ripe cuttings from early- to mid-summer. Remove the lower leaves and root in sand.

Purchased seed is easy to germinate, but saved seed may not breed true to type.

Cut the plants back severely after flowering to prevent seeding and encourage healthy foliage growth and secondary blooms.

Do not prune in fall. Remove damaged foliage in spring.

Short lived if drainage is poor or weather is hot. Divide every 1 to 3 years.

More growing information: How to Grow Perennials

‘Aurea Variegata’ has green leaves with yellow markings and purple-blue blooms.

‘Barker’s Double’ has showy double blue-purple blooms.

‘Bob Sanders’ grows 10 inches tall plants with large double flowers in shades of reddish purple.

‘Campbellii’ has double pinkish-purple blooms.

‘Carnival’ flowers prolifically producing purple blooms.

‘Dr. Mules’ grows 6 inches tall with dark violet flowers.

‘J. S. Baker’ has striking blue-purple flowers with white “eyes.”

‘Parkinsii’ has rosy purple flowers with white “eyes.”

‘Purple Cascade’ grows 4 inches tall with purple flowers.

‘Red Carpet’ grows 4 inches tall with deep red flowers.

‘Variegata’ grows 4 inches tall with gold and green leaves and purple-blue flowers.

‘Whitewall Gem’ grows 8 inches tall reddish-purple flowers.