Invasive Lamium

Mention the word “invasive” and most gardeners will throw up their hands - but one can always turn a problem to one’s advantage if one goes about things the right way – or so I have found.

Credit: Peter Symcox

Some time ago I was given a few tendrils of Lamium galeobdolon, with the warning that it needed careful control.

As I wanted an interesting ground cover for my woodland garden – moist, cool and planted with various rhododendron, azaleas and species lilies – I set the tendrils among the established shrubs. Yes, it is invasive, and soon I had a carpet of green leaves throughout the whole area; they crept across the floor of the garden, draped themselves over the stone edging (and very nice they looked, too), and then, the following summer, spikes of bright-yellow flowers spotted with the palest brown appeared. I was delighted, for this was exactly what I had wanted.

However, the word “invasive” began to take on another meaning when I discovered lamium tendrils poking up through the cowslips and primroses and almost smothering several azaleas. So, they were stripped back ruthlessly, torn out of the earth – no other word could possibly do – and the whole thing given a very sharp lesson indeed in self-control. It didn’t seem to matter; nobody was the worse for it. And so, if you pay attention to the siting of the plant, are careful, keep things well in hand – literally – L. galeobdolon can be very useful.

There are other varieties, of course; all of them are frost hardy, all of them grow in moist, damp soil, and are well worth the trouble of looking after – that is, if you want an almost carefree ground cover. The common name is “deadnettle,” but they are actually members of the mint family. The square stem reminds us of this. Less invasive are the cultivar ‘Hermann’s Pride,’ with its mid-green leaves and pink flowers; L. maculatum (often seen growing wild in the woods – I first saw it in Vermont), which has green leaves with silvery streaks; and L. album, which has, naturally, white flowers. Interestingly, the flower colour provides clues for planting and light requirements; white and purple are planted in spring and need full sun, while those with yellow flowers are planted in fall and prefer shade – ideal for the woodland garden.