Euphorbias are members of one of the largest plant families: the Euphorbiaceae.  This family contains 300 species and around 7,500 varieties.  The Euphorbia species alone includes about 2000 varieties: annuals, biennials, perennials, grasses, shrubs and trees.  Some of these have succulent type leaves, some are deciduous, others evergreen; some are extremely hardy whilst others are tropical and very tender.  In fact the most interesting thing about Euphorbias is the amazing range of plant forms they display, especially in terms of size; conditions in which they grow: tolerance for heat and water needs; and the varying lengths of time for which any individual plant can live. Most euphorbias contain a milky liquid but sometimes this can be colourless.

Euphorbia marginata, or Snow-On-The-Mountain, is an erect annual native from Minnesota to Colorado and Texas. The light green leaves are ovate to oblong, 1 – 3 inches (2,5 – 7,5cm) long. With broad variegated margins, the plants are conspicuous in the landscape, usually between 2 – 4 feet in height with a single stem. The latex they contain is corrosive to the skin and may cause severe burns or dermatitis. As with all members of the Euphorbiaceae, plant parts should be handled with care, especially when sap is showing.

Plants flower in early autumn; the flowers (actually inflorescences and their showy bracts) form small white cups, known as cyathia, at the top and center of the plant. White and green bracts provide the colouring. Snow-On-The-Mountain makes a long lasting cut flower if the cut end is seared or dipped in boiling water.

Euphorbia marginata need full sun to partial shade, with a well-drained soil mix. They are not particular about the soil. The plants should be well watered and be allowed to dry before watering again. The plants are native to poor soils and do not need fertilizer or excessive water. Too much water or fertilizer will provide lush growth but at the expense of flowers. Euphorbia marginata are propagated from seed. Seed should be sown where you want the plants to grow.

Snow-On-The-Mountain when used in landscaping they are often planted with dahlias, mums and other autumn flowering plants. Whether grown in containers or in beds in the garden, they are very showy.