Euphorbia characias ssp. wulfenii (spring 2004)

Spring brings many delights, including the acidic lime-green cupped bracts of spurges, such as Wood Spurge (Euphorbia amygdaloides), which I wrote about in April 2012. One of the finest of these is the Mediterranean spurge Euphorbia characias subsp. wulfenii, which is looking lovely at the moment. As an evergreen with tall stems clothed with blue-green leaves it provides interest and structure throughout the year, but in spring the plant shines out from its surroundings, whether the day is sunny or dull.

The ‘bracts’ are actually specialised structures called cyathia (singular: cyathium), found only in the genus Euphorbia, part of the family Euphorbiaceae (spurges). Each cyathium is made up groups of separate male and female flowers and each of these flowers consists of just a stamen (if male) or pistil (if female) and there are no sepals or petals. The cup which is underneath and supports the cyathium is called the involucre and it contains nectaries that produce nectar to attract pollinators.

In the wild, Euphorbia characias grows along the northern side of the Mediterranean Sea from Portugal to Turkey. Two subspecies have been recognised: Euphorbia characias ssp. characias and Euphorbia characias ssp. wulfenii. Subspecies characias has weakly trapezoid dark purple to black nectaries on its involucre; subspecies wulfenii has crescent shaped yellow nectaries with distinct horns.

In the garden, Euphorbia characias ssp. wulfenii is widely grown. It grows 1 – 1.5 metres tall, with a similar spread, and likes well drained soil in a sunny sheltered spot. It used to do well (pictured above) in a fairly sunny sheltered border on loamy soil in our previous garden. In our new garden we are growing it in a sunny south-facing raised bed and in sandy, thin soil under our living room window (pictured below).

Euphorbia characias ssp. wulfenii, growing in a south facing border (early spring 2015).

There are several named cultivars of Euphorbia characias, including ‘Humpty Dumpty’ (a dwarf form, growing to 30cm high), ‘Lambrook Gold’ (to 1.2 metres, with large bracts),  ‘Black Pearl‘ (to 90cm, with dark nectaries, so presumably a form of Euphorbia characias ssp. characias) and ‘Portuguese Velvet’ (to 50cm, with very blue-grey foliage).

Euphorbia characias is a fairly short-lived plant, lasting no more than five to seven years. It can decline quite quickly: our first plant was doing very well in 2004, then became rather gappy in 2005 before dying altogether in 2006. The better drained the soil, the longer the plant will live. It also dislikes cold winds. Each upright shoot is biennial and should be pruned to its base in June or July. Pruning not only tidies the plant, it rejuvenates it to some extent, and new shoots will be produced almost straightaway. Use sharp secateurs and wear gloves to protect your hands from the irritant sap. Euphorbia characias will self-seed, but if you have a named variety, the seedlings may not come true.

Euphorbia characias mixes well with other Mediterranean plants. The one growing under our living room window is growing beside a Ceonothus ‘Blue Sapphire’, which has contrasting dark green foliage, flushed with bronze. In the raised bed, low sun-loving plants such as Erigeron karvinskianus continue the interest through the summer and the nearby Stipa gigantea should add height and airy movement when it flowers. It will be a good companion, provided it is given enough room and its leaves don’t cover the Euphorbia. The Australian iGarden website lists some other possible planting combinations. It also reminds me that there is a cultivar with white and green variegated foliage and white bracts called ‘Silver Swan’. I grew it (or a similar cultivar) once but I don’t really like the variegation and the cultivar lacks the vivid acid lime-green that attracts me.

Also in our front garden, we have a Caper Spurge (Euphorbia lathrys), which I wrote about in April 2012, and some Cypress Spurge (Euphorbia cyparissias) and the Myrtle Spurge (Euphorbia myrsinites). I do like spurges and I’m not the only one, as is shown by this article in The Guardian by Ambra Edwards.