Euphorbia amygdaloides var. robbiae (x) martinii Whistleberry Garnet

The Euphorbia 'Whistleberry Garnet' is a recent variety of Euphorbia, with a compact growth, notable for its young shoots of burgundy red in late winter. They emerge from beautiful bronze-green foliage, a lovely prelude to its acidic green flowering, particularly bright in spring. Very attractive throughout the year, it is a frugal and undemanding plant, adapted to drought, superb alongside blue flowers, precious for enhancing a dry garden, an ungrateful slope or a rockery.

'Whistleberry Garnet', which appeared spontaneously in April 1995 in the garden of American landscaper Tessa Hobbs, is probably the result of a cross-breeding between Euphorbia amygdaloides var. robbiae and Euphorbia x Martinii. The latter is a natural hybrid that appeared in the south of France, resulting from Euphorbia characias and Euphorbia amygdaloides, the rhizomatous wood spurge. These two species coexist in nature and are native to the western Mediterranean Basin (Portugal, western Morocco, Turkey) for the former, and to a large part of Europe and Asia Minor for the latter. All these plants belong to the Euphorbiaceae family. Their foliage remains evergreen all year round, even in winter.

This variety, which has slightly trailing rhizomes, grows quite rapidly and its adult size will not exceed  60 cm in height and 50  cm in width. It has a bushy, low and dense habit. Flowering begins with the appearance of young shoots in February-March. Then these young shoots elongate and unfold into red-purple stems with numerous very bright inflorescences, almost fluorescent in April-May. This flowering is very unique and rare in nature due to the construction of the inflorescences: no petals, but brilliantly coloured leaves and bracts to attract insects. At the centre of this 'corolla', called the cyathium, are the floral organs and four red nectar glands that form a nice contrast with the green-yellow bracts. This flowering is so abundant that it almost hides the evergreen foliage, consisting of long dark green to bluish-green leaves that droop down, inserted along the red stems. The fruiting is a pendulous capsule that explodes to release its ripe seeds far away. The plant secretes a white latex, which is very visible when breaking the stems. This latex is toxic and it is essential to protect your hands when handling the plant as it can cause skin inflammation.

Plant the 'Whistleberry Garnet' euphorbia in light, poor, moist to dry and especially well-drained soil, conditions that it will find in a rockery, on a slope, or in a dry garden, but also not far from trees. What should be avoided is excessive winter moisture, which can greatly affect the hardiness of this plant. A soil rich in gravel gives good results. It can be paired with early blue blooms for a pleasant contrast, such as those of Iris pallida variegata, 'Corsican Blue' or 'Sappho' rosemary if you live in a region with mild winters, or Anemone blanda, dwarf iris, or aubrieta if the winter conditions are harsher. This Euphorbia also pairs well with small ornamental grasses such as Miscanthus Samurai or Yaku Jima.