Leadwort is a highly underrated ground cover of great beauty and considerable late-season interest. It is durable and long-lived and requires very little maintenance. The only drawbacks are that it is not evergreen -- except in the southern regions (growing Zones 8 and 9) -- and that it is slow to emerge in the spring. However, once leadwort breaks dormancy it grows rapidly.
Description of leadwort: This perennial is a deciduous or semi-evergreen ground cover that grows 6 to 10 inches tall. It has glossy green leaves on long, trailing stems and bears gentian-blue flowers. The 3/4-inch diameter flowers begin in early August and continue until frost. The foliage turns a lovely reddish bronze after the first frost and persists well into winter.
How to grow leadwort: Plant in well-drained soil that is rich in organic matter. Leadwort likes full sun or part shade. It will rot if the soil stays too wet, especially in winter. In most of growing Zones 5 and 6 plants die to the ground in winter. Apply a light winter mulch, and wait until growth resumes in mid-spring to cut stems back to the ground. Plant only in the spring: Leadwort needs a full growing season to get roots established.
Propagating leadwort: By division in the spring.
Uses for leadwort: Plant as a ground cover under shrubs and small trees and interplant spring-blooming bulbs such as crocus and daffodils. Leadwort should not be combined with other perennials because it tends to outgrow neighboring plants.
Scientific name for leadwort: Ceratostigma plumbaginoides