Overview and Description:Euphorbia is a very large genus of plants, with over 2,000 species. About 1,200 of them are succulents, some with bizarre shapes and wide fleshy leaves and others that look remarkably like cacti, complete with spines. Among the the non-succulent deciduous Euphorbia plants are shrubs, annuals, and perennials like milkweed and the popular holiday plant, Poinsettia.
- Leaves - There's not much commonality of leaves in the Euphorbia genus, but they all exude a milky sap, or latex, when their leaves or stems are wounded. This sap is very irritating to skin and eyes and is poisonous. Wash your hands well.
- Flowers - A Euphorbia flowers is called a cyathium (plural: cyathia). The cyathia are tiny, with no petals or sepals. They are usually surrounded by brightly colored bracts, with can last several weeks or month
All cyathia are asexual, but most Euphorbias are monoecious, having both the male and female flowers on one plant. However there are a few dioecious Euphorbias, like Euphorbia obesa, with separate male and female plants.
Botanical Name:Ehphorbia spp. and hybrids
Common Name(s):Spurge is the common name for Euphorbia, because of its purging qualities. I would caution you against testing it out though, because it can be quite toxic.
Hardiness:Most of the succulent Euphorbias are not frost tolerant. There are a few evergreen species, like creeping Euphorbia antisphilitica (Wood Spurge), Euphorbia polychroma (Cushion spurge) and Euphorbia myrsinites (Donkey-tail Spurge) that will survive down to USDA Hardiness Zone 5.
Light Exposure:These plants prefer full sun, but most can tolerate a little partial shade.
Mature Size:Mature size varies greatly with species and variety, from a few inches high to large shrubs to tree sized plants.
Bloom Period:Most Euphorbia bloom in spring or summer and go dormant in winter.
Design Tips:Euphorbias are popular as popular for their structural intrigue as for their drought tolerance. Use the tall angular varieties for focal points and the floppy or chain-like species to spill over containers or walls. Many succulents have infrequent or inconsequential blooms, but Euphorbias will provide color in dry gardens for long periods of time. Mixing them with groupings of Senecio and Agave will create a garden full of texture and leaves of gray, blue, yellow and deep green.
Many of the succulent Euphorbias are slow growing and make excellent container or house plants. I prefer them on their own, rather than mixed with other plants, but their architectural quirkiness will make them standouts in any crowd.
- Euphorbia grandialata - Start out upright and spread in to a bush. Thorny. Corel red bracts in summer. 6 ft. (h) x 8 ft. (w)
- Euphorbia lactea - Fan-like scalloped branches and black spines. Grows to tree size (16+ ft.)
- Euphorbia milii 'Crown of Thorns' - Thorny, bushy plant that loves warm, wet weather. Bracts in shades of red, yellow, orange and white will open throughout the year. 6 ft. (h) x 5 ft. (w)
- Euphorbia obesa 'Basketball Euphorbia' - round and plump, with reddish stripes. Can handle some shade. It gets more columnar with age 8 in (h) x 5 in. (w)
- Euphorbia symmetrica - A subspecies of Euphorbia obesa remains small and round.