For years – I mean decades – I’ve been trying to establish the difference between Echium fastuosum and Echium candicans. And now it appears that the names are synonymous. Yes, that makes it much simpler, and I’m mighty glad for that. But it also makes me grumpy that I’ve spent years trying to see the differences that so many lame references claimed to exist. I thought I was the problem, when it was them all along.
Echium ‘Heronswood Blue’ is a very fine, brilliantly electric-blue colour selection of this striking shrub. Or maybe it would be more accurate to say ‘of mostly this shrub’, as there may be traces of other species in there. Echiums are notoriously promiscuous, and no one can really quite vouch for the purity of pedigree of this, or almost any echium grown here in Australia. Indeed, it’s this promiscuity, and also variability, that makes buying an Echium, other than one specifically named, and vegetatively propagated (and therefore a clone of its parent) such a lucky dip. They’re all worthwhile, but some are much better than others.
There’s a lot to love about Echium candicans, and specifically ‘Heronswood Blue’. It’s fast – I mean CRAZY fast – in growth, it loves poor soils, it revels in heat and dry, and in full bloom is as showy as it’s possible for any flowering shrub to be. Of course all those remarkable qualities are going to be offset by some irritating characteristics as well (as they nearly always are in people), and Echium candicans can be very short-lived, and has a habit of collapsing rapidly and dramatically, due to what appears to be fungal attack.
Echiums candicans insists on perfect drainage. It’s a non-negotiable. And it’s extremely susceptible to frost, which is hardly surprising, given that it comes from the island of Madeira. Like so many shrubs from hot, dry parts of the world, it will respond very well, initially, to the well-fed soils of gardens, but its consequent rapidity of growth will almost certainly be at the expense of its longevity. Such plants last longest, both in actual life-span as well as in their effective contribution to the garden (not the same thing!), in low-nutrient soils that curtail their growth rate. In most garden settings, it’s worth considering that you’ll be replacing Echium candicans on a three-to-five year basis. It’s well worth it.
The plants themselves, even when not in bloom, can be quite striking when young and vigorous, forming a tight dome of silvery rosettes. The density of the dome tends to thin as old flowers are deadheaded, and it some point you’re forced to consider whether your plant is past its use-by-date.
Unfortunately, Echium ‘Heronswood Blue’ doesn’t come true from seed, so summer cuttings are probably your best succession plan, or a return trip to the nursery.
Deviating for a bit away from ‘Heronswood Blue’, by far the most striking and seriously elephantine forms of echium I’ve known appear to have been hybrids between the shrubby E. candicans and the monocarpic (once flowering, followed by death), single rosetted E. pininana. They’re roughly shrubby, though not as branched as straight E. candicans, and their flowers, snaking to the ground, then rise and arch overhead, to about 2m. E. pininana itself grows straight up, in a single tower, to up to 3m. The best planting – by far – I’ve ever seen of this was at Winterhome garden in NZ, in which a long narrow avenue of tightly trussed Italian cypress were backed by a solid forest of equally narrow, and upright echiums.
Then, of course, in total breach of the single-plant-focus that this blog is supposed to follow, there’s the pinky-red Echium wildprettii. It’s such a collectors plant here that you only ever see it in Australia as a single specimen. A repeat planting of them, as I saw about a decade ago in the glasshouses at Longwood, in the USA, looks like something dreamt up by James Cameron for Avatar.
We’re going to visit Winterhome in April, on our amazing eight-day NZ tour. Why not come with us? Check our the details at https://www.travellingmasterclasses.com.au/life-changing-design