PLANT OF THE WEEK #28: Euphorbia rigida

When Mike Morant of Antique Perennials mentioned in his recent Plant of the Week featuring Thalictrum, that Euphorbia rigida would make a worthy subject, my first thought was ‘Already done, Mike!’.  I went scrolling back through the (now) twenty seven plants we’ve done to find out how long ago it was that it was featured.  There was no sign of it.

Like, what?  How is that possible?  Euphorbia rigida is a stalwart of my garden year round, and has been nothing less than the star of it throughout late winter and early spring, featuring with embarrassing regularity on my Instagram feed.

So here it is.  I vividly recall the introduction of E rigida to the nursery trade, some time in the mid-90’s.  I loved its blue-silver colouring, and the mathematical precision of the leaf arrangement, but thought it a bit gawky, and couldn’t figure out how I’d use it in my habitually tall perennial plantings.  We kept each other at arms length, Euphorbia rigida and I, for about twenty years.

Then, in order to create a garden context for small bulbs, I started thinking about devoting a whole part of the garden to a low, matrix-like planting of grasses and low, mostly evergreen perennials whose primary purpose was to create a permanent background – the basic warp and weft that could be seasonally gilded with the passing show of bulbs.

A client offered me a few seedlings of Euphorbia rigida, and with mild enthusiasm, they were transplanted into my garden.  I had no idea, back then, of just how important they’d become.

Throughout summer – their quietest period – they provide a dome of silver pointed foliage that would have old Mr Fibonacci doing a jig right there in my Steppe.  Over winter, the apices of each stem start to colour up and congest, stained with ruby, bronze or lime, before exploding into flowers of screaming sulphur-yellow.  Over a month or two these slowly cool to lime, and then, in my climate at least, age to coral and eventually to carmine.  No other plant in my garden could boast as many seperate showy stages.

But what’s become clear over this spring, via many instagram accounts, is that not all these stages show for everyone.  And many can’t keep it happy at all.  The simplest take home message is that it wants it tough.  Really tough.  It prefers perfectly drained soil, and appears happiest if it gets absolutely no water over summer.  Like its cousin, Euphobia characias ‘wulfenii’, it’s happiest where it self sows.  Both of these plants seem to be subject to some integration issues when transitioning from the potting mix they were purchased in to the native soil.  My experience is that the best performing and longest lived of both are the self-sown offspring of my original plants.

Euphorbia rigida seems curiously tolerant of shade, but is never at its best unless in full sun,  Indeed the more sunshine it gets, the more of the pre-flowering colour you’ll get, and the more of the coral seed-head colouring you’ll get.  The best of my plants have self-sown into a west-facing bank where they get no water at all.   It’s also at its best in company either low than, or at a similar height to it.  Consequently I find it to be an almost useless ‘border’ subject, looking best in a sparse, gravel-garden setting, or some other form of naturalistic planting.

Having paid scant attention to Euphorbia rigida for two decades, I don’t now know what I’d do without it.  Context is, of course, everything.  It seems like it’s going to take at least one full lifetime – maybe one and a half – to really get a grip on that.

Discussion

  1. Stunning Michael! I must add it to my steep rockery garden and see how it goes. Thank you – I too have seen it and avoided it. My E. ‘Craigeburn’ is flowering at the moment – not as vibrant and E. rgidia but a very useful winter plant too.

    1. Give it a go. I totally love E ‘Craigieburn’ also, but it doesn’t cope well with the extent of my dry. It really likes quite good garden conditions. As you say, it’s not as bright, but the combination of the plum foliage and lime flowers is fabulous, It really makes me think just how free of any down-time so many Euphorbias are. So, so few plants can boast that, and this genus contains many species that can.

  2. I have this and wulfenii in my inherited garden and they look amazing. They’ve self seeded all over the place into gravel pathways. One of them, maybe wulfenii, spits it’s seeds out with a “crack” in summer but I’m never quick enough to see them pop out. I only hear them after the fact no matter how long I stare!

    1. They both do, in my experience. I’m forever hearing that crack in hot weather in late spring. Last year I promised seed to a nursery, and was watching it carefully as it ripened.. Then I was away for a v hot week in November, and when I got home, there wasn’t one seed left on my hundreds of E rigida plants.

  3. Loving the photos…and I’m so envious. Over here on colder, wetter Dartmoor, Devon, Euphorbia rigida is much coveted and pretty impossible. I’d been chasing it for years for my very free draining granitic soil/gravel garden with no luck, until finally being told it wasn’t stocked as needed the hotter drier S.E. to have a chance. Euphorbia myrsinites is the closest I can get for height and hardiness but fails on the multi colours scheme.
    When I’m missing home I dream your Steppe garden. Thanks for all your videos, they keep me going and I’m really enjoying the readings of your first book too.
    Often pop into my own copy

    1. I so get where you’re coming from. At the same time, I follow lots of British instagram accounts, and pine for all the juicing things you can grow. The longing is almost unbearable, at times, and I wonder if I’ll ever be able to grow anything water-loving ever again. Thank goodness we now have the means, like never before, to enjoy, daily, what’s going on in other’s gardens, in other places, and other climates, hey?

  4. Thanks for this one, Michael. I’m enjoying E.rigida. Doing well for me in a dry spot where I have scraped out small pockets of soil between sheets of granite rock to plant it. Treating it mean keeps it keen. (with borrow from “Kath and Kim”)

    1. I’ll be really interested in how it fares, Annette. I imagine it would absolutely love those conditions. Mine don’t love the cold, wet winter, as my soil is very retentive, but they suffer beautifully by turning crazy purple tones like the plant in the second pic above. But I suspect that retentive soil does help them get through summer with no watering at all. I’m guessing you’ll be watering, if just a little, but I’d love to hear how they go. (if you can bring yourself to experiment with one or two) with no water at all. I guess it’d be pretty tough on those Sicilian hillsides upon which they grow wild.

  5. Hi Michael. I am loving your Euphorbia rigida and is a species I am definitely going to try. Thank you! My Euphorbia trials from last year were of a variety of martinii called ‘Rudolph’ and I can highly recommend it, especially the deep red tips during winter.

  6. Yes, you’re right Michael. We are lucky, …to be able to enjoy watching, reading and talking to others about so many gardening styles, situations, ideas and passions from around the world, through this media and of course wonderful books.
    When I first moved over here from central Victoria, this wasn’t possible. Now, whenever I need to touch base back home, I can!
    Still crave for a proper, dry garden though…the scent of the earth and foliage is sooo different.

  7. Love this plant! It is worth noting the milky sap can definitely irritate skin and eyes though! As with all the euphorbias.

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