by Sally Gregson.

As the daylight hours shorten and winter’s breath cuts across the garden air, the role of evergreen plants begins to take on more importance. They have served as background planting all summer and now their architectural substance brings structure and form to the winter borders.

Few evergreen perennials look as well in a sunny border as Euphorbia characias. Its upright stems, clothed in blue-grey leaves, stand like broad-shouldered sentries guarding a wall or the corner of a fence. Sometimes the wind creeps in and around, and spills open their stems like a child’s game, so it’s as well to position a new plant carefully, out of the weather.

As the winter turns, their stout stems gradually straighten to over 1m, and hook over like umbrella handles, their flowers enfolded in lime-green petal-like calyces. Until by spring they resemble tipsy guardsmen in lime-green busbies, populating a garden full of bright showgirls – the tulips and daffodils.
Euphorbia characias is a plant of the Mediterranean region. It needs good drainage as well as sunshine, and is fairly short-lived. After a few winters an older plant becomes disoriented and falls apart. Usually by that time its seedlings will have put themselves around the mother plant, ready to usurp their parent. The seeds form in explosive pods which detonate with a loud pop. On a sunny day a stand of ripe stems can sound like distant machine-gun fire at midday.

Once the flowering stems have faded in summer, cut them back to the base to encourage new growth and extend the life of the parent plant. This form of Euphorbia hates its roots being disturbed, so it’s a question of finding the right seedling in the right place, rather than trying to transplant them. Or, of course, they are available from specialised nurseries as pot-raised young plants.
Over the years several named forms of E. characias have been selected. Among the most popular is E. characias ‘Black Pearl’, whose true flowers resemble distinctive black eyes winking from among the lime green bracts. And E. characias ‘Portuguese Velvet’ is a more compact form – up to 40cm in all directions, with silvery grey leaves. Neither will come ‘true’ from seed, so take cuttings from a mature plant, being careful not to touch the irritant juices. They root easily and will flower within a year.