Robb’s spurge
Euphorbia amygdaloides var. robbiae
This spurge readily forms colonies of upright stems with dark-green, glossy, evergreen foliage. It grows well in full sun, part-shade and even full shade, coping with dry soils once established. In spring, it produces sprays of lime-green flowers which rise from the stem tops, creating a subtle yet sophisticated display.
Spreading by underground stolons, it can potentially get out of hand. However, this makes it ideal as a dense ground cover beneath trees (see below). However, it can be used in mixed plantings, as long as there is opportunity to pull up stray stems. A good example of such use can be seen around the walls of Christopher Lloyd’s Great Dixter house, where it is grows harmoniously with ferns and willow gentian.
Robb’s spurge has an RHS Award of Garden Merit.
△ Robb’s spurge used as a ground cover in public planting (London)
Background
Although Robb’s spurge is a variety of wood spurge, so perhaps should have been included on the previous page, from a design and planting perspective, it is sufficiently different to me to deserves its own page.
It was discovered in 1891 by Mary Ann Robb, a botanist and plant collector, in a woodland area near Istanbul, Turkey. Robb’s spurge differs from common wood spurge, Euphorbia amygdaloides, in several important ways. Firstly, it spread by runners with stems popping up from the ground, creating a gradually spreading colony. In contrast, the common wood spurge forms a clump with new shoots emerging from the base of older ones. Secondly, the foliage is broader, more waxy, glossy and dark green. The whorls of leaves form tight rosettes towards the stem tips, creating a distinct visual effect which in some situations makes it look more like a low shrub.
△ In my garden Robb’s spurge occupies a bed with foxgloves and ferns.
A few escaped shoots now grow at the foot of an adjacent yew hedge. I previously tried it in the shady beds alongside my workshop, where I planted it from a 5L garden-centre plant, but it started spreading too quickly invading adjacent plants. The next year I dug it out, but a few shoots that I missed continued to grow in a much more controlled way. These never became a problem, and I realise now that it is one of those plants that in many ways improves if you are brutal with it. As an aside, Japanese anemone falls into the same category: a plant that quickly spreads by runners (especially through mulches) and become a nuisance if left, but by simply pulling it up (roots and all) every now and then, I keep its growth open and sparse — which looks to my eye, far more natural than the usual dense, aggressively spreading clump.
Euphorbia ‘Robbiae’ GALLERY
Winter foliage – looking like an azalea!
Flowering shoots unfurl
A little colony is forming under my yew hedge
Robb’s spurge has small geometric flower heads
The flowers expand into larger flower heads with subtle lime flowers.
Over the summer, flowers often fade to reds or oranges
Late colour seems to be enhanced when grown in full sun
Old flowering stems removed to show off the new overwintering foliage. Here, with Japanese Tassel ferns
Planting Ideas
Below is a shady bed in my front garden, framed with clipped dwarf box (bottom), and backed with shrubby Sarcococca confusa (top). The three main perennials in this bed are Robb’s spurge (left), white foxgloves (centre) and Japanese tassel fern (right)
▲ With shrubs
The glossy foliage of Robb’s spurge makes it an ideal ground cover between evergreen shrubs such as rhododendron, sarcococca, skimia, buxus and butcher’s broom or grow it as a tough ground cover under deciduous trees or leggy deciduous shrubs where it will stand out in winter.
▼ With perennials
Hosta, Hellebore and white or blue Gentiana asclepidae (see below) are strong enough to live alongside Robb’s spurge
So very useful, inormative, inspiring. Unable to express my enthusiasm und my gratitute in words. The WORLD’s best garden blog, ever!
Thank you so much Monica! I’ve been working on this article on and off for over a year. It took a big push over the last few weeks to get it finished, so I’m grateful for your appreciation.