'Caradonna' is suitable for growing in USDA hardiness zones 4 to 8, and is best suited for full sun locations. It does well in dry conditions, but it flowers best if it gets regular moisture. Lamium maculatum is perhaps best known as a ground cover plant with silvery foliage, but the cultivar 'Purple Dragon adds light purple flowers.
Lamium maculatum (also known as deadnettle ) grows no more than about 9 inches in height and is appropriate for USDA hardiness zones 4 to 8. It is generally grown for its foliage, but there are a number of cultivars that offer attractive flowers, as well. In addition to 'Purple Dragon,' there are white cultivars and red/purple cultivars, such as 'Red Nancy.' This is a good plant for dry shade, but it can be somewhat invasive. Although a good ground cover, it does not tolerate foot traffic. Alliums are a nice addition to the landscape, not only for their color but also for the globular shape. Among the best cultivars and varieties with purple color are Allium 'Purple Sensation,' A . Like other spring-flowering bulbs, purple alliums need to be planted in the fall.
The specific planting date in fall is determined by where you live. Plant in December if you live at the other end of the scale (warmer climate), in zone 8. For those in between, plant in October or November. Heights range from 2 to 5 feet, depending on variety, and alliums typically flower in late spring to early summer. Alliums are available for all plant hardiness zones. Petunias are normally planted as annuals, so you can grow them in every plant hardiness zone. They are perennial in USDA hardiness zones 10 and 11. Petunias are commonly used in hanging baskets, window boxes and as bedding plants. There are dozens of petunia cultivars with purple flowers, and more are introduced each season. Purple petunias say "royalty," not only with their color (purple is the color of royalty) but also with the fine, velvety texture of their petals. The flowers that go by the common name of columbine include several Aquilegia species, including many cultivars of Aquiliegia vulgaris that have violet or purple flowers. New cultivars are introduced regularly, but some with notable purple or lavender flowers include Aquilegia vulgaris '' Double Clementine Purple' with large double blossoms, Aquilegia vulgaris ‘Winky Purple-White,’ with white and purple blossoms, and Aquilegia vulgaris ‘Clementine Dark Purple,’ with fluffy double-pedal flowers. As a group, the columbines have delicate flowers that appear in April and May. Aquilegia vulgaris and its cultivars are suitable for growing in USDA hardiness zones 3 to 8, in sunny to partial shade locations. They work well in cottage gardens and rock gardens. The terms larkspur and delphinium are sometimes used interchangeably, but each is actually a different genus within the Ranunculaceae family of plants. True larkspur s are annual flowers ( Consolida ajacis is the most common species grown in gardens) that are different from perennial delphinium ( Delphinium spp .). The two types share a similarity in appearance, thanks to their shared family heritage. Unlike delphiniums, which are temperamental, hard-to-grow perennial plants, annual larkspurs are quite easy-to-grow, tough, hardy flowers. They grow to about 3 feet in height and do best in ordinary moist garden soil. Although they are annual plants, larkspur may self-seed freely, producing plants year after year. Be aware that larkspurs are poisonous, so be careful planting them where pets and children will be present. Larkspur grows quickly from seed, blooming in spring and summer. Lobelia is an annual flower that blooms from summer through the first frost. There are numerous varieties of lobelia plants, but the cultivars providing blue/purple flowers are usually Lobelia eranus. They begin blooming in mid-summer and continue to the first frost.
Lobelia flowers tend toward the blue side rather than true purple; some common varieties include Lobelia erinus ‘Bella Aqua’, Lobelia erinus ‘Bella Aqua,' and Lobelia erinus ‘Hot Water Blue,' all growing 10 to 12 inches tall. The classic deep purple perennial clematis is 'Jackmanii,' a flowering vine that grows well in USDA hardiness zones 3 to 8, producing large 7-inch wide, deep purple flowers in mid summer. There are dozens of other clematis that produce purple/lavender blooms, including: Clematis ‘Warszawska Nike,’ is a 10-foot vine that flowers with deep purple in late spring to early summer, then again in fall. Clematis ‘Etoile Violette,’ grows to 12 feet and produces dark purple, velvety flowers throughout the summer. Clematis ‘Kingfisher,’ produces lavender flowers in May and June, then again in September. Clematis ‘Picardy,’ has smaller, but more profuse flowers than most other varieties. Most clematis are hardy in USDA hardiness zones 3 to 8. A trick to success with clematis vines is growing the plants in sunlight but keeping the roots cool.
This may be achieved by mulching the root areas or planting low plants over the root zone to provide ground shade. Some types flower on the previous season's wood, others on new growth. Make sure you know what type of clematis vines you have before pruning them.