Euphorbia, part of the spurge family, is a plant of many colours, shapes and sizes. The genus contains more than 2,000 species of both annuals and perennials. Choose the most recognised euphorbia on the planet, poinsettia, or select the delicate-looking hybrid euphorbia, Diamond Frost, a one-footer that produces masses of small white flowers from spring to fall. If you want more drama in the garden, plant tropical smoke bush (Euphorbia cotinifolia). Growing to 15 feet tall, this treelike euphorbia has red leaves that darken to burgundy. You can propagate most euphorbias with stem cuttings, but you can grow some from seed or plant division.
Propagating From Seed
Although primarily propagated from cuttings, poinsettias produce seedpods when they finish blooming. Once the red bracts are faded and brown, collect the pods and place them in a paper sack to dry. Don't worry if the pods explode. Simply collect the seeds and plant them in pots, lightly covering the seeds with soil. Keep the soil moist and out of direct sunlight, and the seeds should germinate. Growing less than a foot tall, Euphorbia dulcis "Chameleon" is an ideal border plant with bronzed leaves. Collect the seed pods in spring and ripen them as for poinsettias.
Propagating From Cuttings
Because euphorbia sap is a skin irritant, as soon as you take stem or root cuttings from your existing plant, place them in water for a day or two to let the sap drain. Take the cuttings out and let them dry before placing the cut ends into the rooting medium. Euphorbia catinfolia and Euphorbia "Blackbird," along with poinsettias and African smoke tree, are good candidates for propagating by stem cuttings. Euphorbia splendens, or crown of thorns, is easily propagated with stem cuttings.
Propagating From Plant Division
Dig up euphorbias and divide the clumps to propagate more plants. African smoke tree, Diamond Frost, cushion spurge and wood spurge (Euphorbia amygdaloides) are easily propagated by plant division. Divide the plants in early spring.
If you don't want to gather seeds and coax them into germinating, choose a self-seeding euphorbia. Chameleon is one variety that self-seeds, propagating all by itself in the garden. Another type is Euphorbia polychroma, or cushion spurge, which produces bright yellow, succulent-looking bracts and grows about 3 feet tall. Sometimes, you can hear a popping noise as the seedpods explode in the garden.