The hardy euphorbias, commonly known as spurges or milkweeds, are good value for money plants, earning their keep as they produce decorative foliage and ‘flower’ over a long period in spring or early summer, according to variety.
Flower is the wrong word, as their flowers are small and insignificant, but are surrounded by conspicuous showy bracts (modified leaves) which remain attractive for several weeks, usually in shades of yellow or lime green, but a vivid red in varieties such as the aptly named ‘Fireglow’.
At the entrance to Clumber’s walled garden we have planted Euphorbia myrsinites; it started producing its yellow bracts in March and is still looking good in spite of all the rain.
It bears trailing shoots, usually no more than six inches/15cm tall with succulent blue-grey evergreen leaves. We’ve planted it in free draining soil in a sunny spot, where it will be well suited, as it grows wild in southern Europe in rocky and sandy places, so a raised bed or rockery would also suit or a place at the front of a border, provided the soil doesn’t get waterlogged.
Two other low growing species are worth considering. E. polychroma forms a rounded mound about 18ins/45cm tall and wide. Its bracts are yellow shading to lime green and appear over several weeks. We’ve planted it in our ‘tropical’ borders next to the glasshouse, again on free draining soil and in a sunny position.
The ‘cypress spurge’, E. cyparissias, grows to about 16ins/40cm and has attractive feathery foliage topped with yellow bracts. In spite of its small stature it is best not planted in a rockery amongst choice alpines as it tends to spread rapidly. Its variety ‘Clarice Howard’ has dark red and purple leaf colouring, whilst ‘Orange Man’ turns rich orange in autumn as the foliage dies back.
The Royal Horticultural Society has begun trialling garden euphorbias and will be growing a selection for a couple of years, comparing them for characteristics such as hardiness, weather resistance and for their general floral impact.
The Plant Finder lists over 300 types so impartial advice to gardeners on those most commonly grown is always a great help.
For the mixed border, euphorbias make ideal companions to bulbs, annuals, ferns and shrubs. They combine well with other May flowerers such as blue pulmonarias or rose ‘Canary Bird’ and variegated or foliage shrubs such as the golden leaved philadelphus, Philadelphus coronarius ‘Aureus’ or bronze tinted phormiums or grasses.
If you like hot colours, then E. griffithii ‘Fireglow’ and the similar ‘Dixter’ will be to your liking. These grow taller, around 3ft/90cm, with a spread of 2ft/60cm, and bear bracts in bright red and orange-red. They are happy in a sunny place protected from wind.
Final choice, and taller, at around 4ft/1.2m is the evergreen E. characias. Foliage has blue-grey shades and flower heads are large, lime-green to yellow with dark brown centres. There are also forms with variegated foliage, such as ‘Burrow’s Silver’, which has cream edges to the leaves.
A word of caution, as with their tender cousin the poinsettia (E. pulcherrima), the milky white sap of euphorbias can cause skin irritation, so wear gloves when weeding around or cutting back the stems of euphorbias.
Jobs for May
We can expect frosts until the end of the month, so don’t be in a hurry to plant out tender bedding plants such as busy lizzies or petunias or tender vegetables like sweet corn or runner beans. These are best gradually acclimatised to outdoor conditions, by putting them outside during the day, bringing them in at night, and then leaving them outside at night, but covering them with fleece.
Lawns will now be growing apace and will need mowing weekly. The height of cut of your mower can be lowered to around 1inch/2.5cm.
Plant tender corms, bulbs and tubers such as dahlias and gladioli.
Continue sowing salad leaves (lettuces, rocket, ‘Bull’s Blood’ beetroot), carrots, beetroot and peas.
If you have greenhouse space, containers and hanging baskets can be planted up and grown on until conditions are suitable for putting them outside. Grown two to three weeks under glass, they will look fuller and more attractive.
a Keep on top of the weeds by hoeing and hand weeding.