Cushion Spurge, Euphorbia polychroma has spring impact with its eye-stopping bright yellow color. Euphorbia in its full blooming glory shines like chrome and that probably explains the adjective part of its name, “polychroma.” The flowers of Euphorbia are really interesting for they are not really flowers, they are bracts on the ends of the stems that turn a brilliant yellow. The blooms last for over a month then the flowers “morph” turning green and become part of the stem.
After blooming, Cushion Spurge lays low keeping a neat tidy rounded shape all season but shines again in fall when the foliage takes on a tawny-bronze color. The shape and perfect mound of Euphorbia gives this perennial a priority status for planting in pots or containers. It’s deep tap root makes the plant extremely drought-tolerant so this is another good reason for its excellence in containers.
Euphorbia is easy to grow and very long-lived; however, the flowers produce a tiny red fruit that when it ripens and pops off will propel Euphorbia seeds all over the garden so there will never be a lack of Euphorbia plants. The seedlings develop slowly and will take a couple of years to bloom but should be moved or gifted to friends before the taproot moves down too deep in the earth making them difficult to transplant.
Cushion Spurge is a zone-four perennial and grows well as far North as Jackson Hole, Wyoming and Rexburg, Idaho, but it never reaches the huge size it grows in warmer areas. Grown in California where it never suffers from freezing temperatures, it reaches shrub-like proportions of five by five.
Note: All parts of this plant are poisonous if ingested. Handling the plant may cause skin irritation.
Watch out! Never confuse this plant with Euphorbia, Myrsisites or Donkey Tail, which is an invasive noxious weed with sap that will burn the skin.