Choosing the best delphinums
Powerhouse Plant For All Seasons: Rosa rugosa

A new colour in a thuggish perennial

Pentaglottis sempervirens (Green Alkanet) in its usual blue, and a new form. Image © GardenPhotos.comGreen alkanet, Pentaglottis sempervirens, is robust evergreen perennial in the borage family (left, click to enlarge). “Robust” is perhaps being kind; frankly, it can be a bit of thug. But in wilder parts of the garden in poor soil it can be very useful, squeezing out less attractive thugs like ground elder. It carries its pretty bright blue flowers on 2-3ft/60-90cm stems above rough and rather bristly green leaves.

Green alkanet originates in south west Europe, was first grown in British gardens in 1700 but had already spread into the wild by 1724. It has since spread over much of England and Wales, but is seen less often in Scotland and Ireland.

It is also found in along the American west coast from California to British Columbia as well as in Maine; in North America it’s as often known as evergreen bugloss. I’m surprised it’s not established itself more widely… and more notoriously.

I’ve been fortunate enough to find plants with flowers in two other colours in addition to the usual bright blue, the latest just a couple of days ago. I’d parked the car in a car park near a large demolition site just a few miles from the RHS Garden at Wisley, just south of London (in the village where the former singer and guitarist from The Jam, Paul Weller, lives as it happens). I got out of the car to go to the post office to post a card to my lovely wife back home in Pennsylvania and I spotted the plant you see in the picture – instead of bright blue flowers, the flowers are white with a ring of blue flashes around the centre. Lovely. But not the time of year to dig it up, unfortunately.

Decades ago I found a form with lovely pale blue flowers, which the owner of the garden where I spotted it called ‘Morley China Blue’; it was available from a nursery for a year or two, but has now vanished.

And about as long ago, photographer and plant breeder John Fielding found a stable variegated version which never self sowed so was very well behaved. He passed it to a large nursery for propagation – and they lost it.

The point of all this, I suppose, is to make the point that even amongst the most familiar (and not universally admired) plants, are interesting and attractive new forms. We just have to keep our eyes open.

UPDATE: Went back yesterday for another look - someone's been in with the weed whacker, just a pile of dried up stems is left. And the marker I'd left so I could go back and dig up the plant in the autumn has gone too...