I can’t tell you how grateful I am, right now, to Verbena rigida. And what I used to find most annoying about it is now the very thing I’m most grateful for.
It has been described as a miniature Verbena bonariensis. That’s a fair call, in that it only grows to about 50cm, and has rich purple hemispherical flower heads on fine, bristly, bolt-upright stems with very little foliage. In that sense it’s just like its much taller cousin.
But it differs in that it runs underground. And it runs like crazy. Back in the day when my paradigm of perennial use was based upon the perennial border, I wanted all the plants to stay put, and produce nice dense clusters of foliage and flower in their assigned position. But now I’m driven more by the aesthetics of naturalism, I love that I can tuck this plant into a gap, and it’ll just run about and find a spot to pop up, and float about or above the matrix planting around without competing with, or casting shade upon, any of its neighbours. That, of course, means that it’s at its best among plants a bit shorter than it, in broad-scale, low planting.
Verbena rigida is totally bullet-proof when it comes to drought, though if it’s dry for prolonged periods of time it stops flowering, leaving interesting, longish cylindrical seed-heads in their place, looking a little like a post-flowered sanguisorba. With rain, or irrigation, it starts flowering again.
With little foliage to call its own, it’s definitely a supporting cast-member, rather than an A-lister. But gardens in general give too much space to the latter, and not enough to the former.
It’s been tricky to get hold of for a few years, being ousted from the market by its lame, washed out mauve form named ‘Polaris’. I intended to give it a well-deserved slamming, but have, while actually typing, reconsidered. Maybe there’s a place for it to hover above my steppe-planting. As a colour-saturation addict, I doubt it, but you never know.
Must try it!