Listed here are the non-succulent flowering Euphorbias with the exception of Poinsettia (E. pulcherrima). The Crown of Thorns (often referred to as a ‘Christ plant’ or the ‘Christ-thorn’) is an old favorite which remains an excellent and undemanding choice for a sunny window. It does not need misting, will withstand some neglect and does not have to be moved to an unheated room in winter.
Leaves may drop during this resting season but new leaf buds wil appear within a month or two. Scarlet Plume (E. flugens) is much less common and its growth habit is quite different. Long arching branches bear Willow-like leaves, and in winter the flower-heads appear – colored bracts surround tiny true flowers. The color is orange or white with a yellow eye. Keep cool and rather dry for a month after flowering.
The most popular one is Euphorbia milii. It is a beautiful plant that will brighten up your home or landscape. It is easy to grow and will provide blooms that last a long time. Its 3 ft stems bear tiny flowers which are surrounded by showy bracts – red is the usual flower-head color but both salmon and yellow types are available. The length of the flowering season depends on the light intensity. E. milii is normally in bloom from early spring to midsummer, but in a brightly-lit spot it can flower almost all year round. The sap is poisonuos.
Euphorbia fulgens (Scarlet Plume) is not often seen and is more difficult to care for. The stems are arched and thornless – quite unlike those of E. milii, but the flower-heads have the same structure.
Secrets of success
Temperature: Average warmth – minimum 55°F in winter.
Light: As much light as possible, but shade rom summer sun. Plants grown in a dark spot will flower poorly, become leggy, and are more susceptible to diseases.
Water: Water moderately from spring to fall. Water sparingly in winter. Let compost surface dry between waterings.
Repotting: Repot in spring every 2 years.
Propagation: Take stem cuttings in spring or summer. Let milky sap dry before placing in compost.
Diseases: Euphorbia milii is hardy and take very little care. The most serious can be prevented by avoiding situations where the soil or foliage remains wet. Remove yellowing leaves and dead foliage that becomes impaled on the spines. These promote disease development by trapping moisture. Diseases include bacterial and fungal leaf spots, fusarium and rhizoctonia stem and root rots and botrytis flower blight.