Myrtle spurge is a succulent perennial that gets up to 4 in (10 cm) tall with stems that can spread a foot (30 cm) or more. The fleshy bluish gray leaves are rounded with pointed tips and very closely packed spirally along the stems which grow upward then fall down, creep along the ground, and grow up again. Greenish yellow “flowers” are borne in clusters about 2-3 in (5-8 cm) across at the end of each stem. Euphorb “flowers” are actually bracts which surround a cyathium, which is the much reduced flower, consisting of nothing but an ovary and a single stamen. Like other euphorbs, myrtle spurge has fruits that explode when ripe, broadcasting seeds a considerable distance in all directions. All euphorbs, when wounded, bleed a milky-white latex that is toxic if ingested and irritating to the skin. The cultivar, ‘Washfield’ has sulfur-yellow bracts tinged with red.
Euphorbia myrsinites is native to southern Europe and Asia Minor. It has escaped cultivation and become established in parts of North America where it has sometimes become a bothersome invasive.
Culture Light: Myrtle spurge does best in full sun. Container plantings need bright light.
Moisture: This spurge is drought tolerant and thrives in any light, well drained soil. It tolerates clayey soils and even soils that retain some moisture as long as they aren’t sopping wet for extended periods.
Hardiness: USDA Zones 6 - 8. Myrtle spurge loves the heat and does well in the southern U.S. It tolerates light frosts.
Propagation: Pieces of stem can be rooted. The plant self seeds abundantly. Myrtle spurge is very invasive and can quickly get away and out of control if you aren’t vigilant.
Although suitable for xeriscaping, stone walls and rock gardens, myrtle spurge is best grown in a container. I call this “creepy” spurge because it is so invasive and sinister. Once established, myrtle spurge will blast seeds and creep its way all over the place. The latex is toxic to humans and wildlife. People can get a nasty skin rash from the juice. Pieces of stem, root or leaf dropped into the fish pond will kill the fish. As if all this isn’t enough, myrtle spurge is allelopathic, which means that it releases chemicals into its environment that prohibit other plants from growing. You don’t want to turn this plant loose. Keep it in a container.
As a container plant, myrtle spurge is noteworthy for its attractive bluish gray leaves and colorful cyathia, subtended by equally colorful bracts. It is a fine addition to your potted succulent collection. Remove fruits before they explode and send seeds in every direction.
The genus Euphorbia is varied and huge with more than 2000 species assigned to it. Based on conservative floral characteristics, the botanists have determined that all these plants, including annual and perennial; evergreen and deciduous; shrubby and treelike; herbaceous and succulent, monoecious and dioecious, are derived from a single common ancestor. All species have milky (and poisonous) sap, and many have spines and are frequently mistaken for cacti. Perhaps the best known euphorb is the poinsettia, Euphorbia pulcherrima. But pencil tree (E. tirucallii) and crown-of-thorns (E. milii) are also well known and popular houseplants.
All parts of Euphorbia myrsinites are poisonous if ingested and the milky latex is a skin irritant and causes severe inflammation on contact with open wounds or the eyes. Seek medical attention immediately if you get the sap in your eyes. Wash it off your hands with isopropyl (rubbing) alcohol. Keep children and pets away.
Because of its highly invasive nature, cultivation and sale of myrtle spurge is prohibited in several states.