Perhaps it’s because the botanical name has ten syllables in it, making it nearly impossible to pronounce, or maybe it’s the rather drab common name, but Ceratostigma plumbaginoides, aka Leadwort, is a plant that does not get the notoriety or appreciation that it deserves. I’ve used it as a groundcover in my garden for almost twenty years and it’s remarkable. It has very unobtrusively worked its way through a border, spreading by wiry rhizomes. It hasn’t overgrown its bounds or strangled companion plants like some groundcovers do. It’s barely noticeable through spring and early to mid-summer. But in September and October, as the days get shorter and temperatures cooler, it covers itself in small gentian-blue flowers. Another common name is Blue Plumbago, much more descriptive. When colder weather arrives in earnest its leaves turn a beautiful shade of red as if to say “Here I am, I was here all along!”
NUTS AND BOLTS
Leadwort grows to just 15 cm. tall. My plant has spread its way along nearly two metres of border length over the years but you could easily control this by digging it out of areas you don’t want it in. It flowers best and has the best fall colour in full sun, although mine doesn’t receive this any longer and it does fine. Ceratostigma is hardy to -28 deg. C but will likely survive colder winters with a mulch cover. Average soil and moisture will keep the plant happy.
PLANT IT WITH…..
Anything! It’s such a well-behaved groundcover that it can be planted with any shrub or perennial that would benefit from a blue-flowered skirting. In my garden it has happily mingled with Spirea ‘Little Princess’ and the perennial Geranium macrorrhizum. I honestly can’t think of a single plant that Ceratostigma wouldn’t compliment in some way. Use it in fall containers with pansies and other cold weather plants.