Euphorbia is a genus of flowering plants that belongs to the family Euphorbiaceae. With over 2,000 species, Euphorbia is one of the most diverse plant groups in the world and includes both annual and perennial species. For example, the Poinsettia (Euphorbia pulcherrima), a popular choice during the holiday season, is the most well-known annual variety. Perennial species may be referred to by their common name, Spurge.
The plants in this group vary widely in size, shape, and habit, but they all share some distinctive features that make them easily recognizable.
Growing and Caring for Euphorbia
Euphorbia plants have specific preferred growing conditions contributing to their overall health and thriving growth. Firstly, they prefer a well-drained soil mixture that mimics their natural habitat. A sandy or loamy soil with good drainage is ideal. Avoid heavy clay soils that tend to retain moisture, as this can lead to root rot. If necessary, amend the soil with organic matter or perlite to improve drainage.
The plants thrive in full sun to full shade. They require ample sunlight to develop their vibrant colors and maintain compact growth. Ensure that the plants receive at least six hours of direct sunlight each day. However, providing some afternoon shade in extremely hot climates can protect the plants from scorching. Striking a balance between sun and shade is key. Plants grown in the full shade do not perform as well and will get leggy. So be prepared to pinch them back regularly.
Additionally, euphorbias are drought-tolerant plants that prefer infrequent but deep watering. Allow the soil to dry out between waterings to prevent overwatering and promote root health. It’s important to note that while euphorbias can withstand dry periods, they still benefit from occasional watering during extended droughts or arid conditions.
Perennial euphorbia are not heavy feeders so go sparingly on the fertilizer. A slow release fertilizer in the spring and in the fall is adequate to keep the plant performing.
The most distinctive feature of the Euphorbia plant is its milky sap, which is present in all parts of the plant. The sap contains latex, which can cause irritation if it comes in contact with the skin or eyes. This sap can be used in many different ways, such as in traditional medicine and as a source of rubber. However, it is important to note that the sap of some Euphorbia species is toxic and can cause serious health problems if ingested.
The flowers of perennial Euphorbia are also unique. They are small and inconspicuous and do not have petals or sepals. Instead, they have structures called cyathia, which are composed of modified bracts that form a cup-shaped structure approximately 1/4 inch in size around the tiny flowers. The cyathia are often brightly colored and are arranged in clusters, making them appear like a single flower. Generally the tiny pin-point sized flower is often the opposite color. For example, cyathia are chartreuse green and the flower is burgundy red.
Perennial Euphorbia make long lasting cut flowers for bouquets. If Euphorbia flowers are not used for cut flower arrangements, they should be removed once spent by cutting the Euphorbia to 6-9 inches. This promotes new and more compact growth as well as more blooms for the following year. Perennial Euphorbia usually flower in the spring. If cut back in late spring, they may reflower in the fall.
Perennial Euphorbia at Martin Garden Center are extremely popular because they also tend to be evergreen during our Upstate winters. Some of the varieties that we carry regularly include:
- Ascot Rainbow Euphorbia, Yellow and light green variegated leaves with chartreuse cyathia and burgundy red flowers.
- Blackbird Euphorbia, Burgundy foliage with yellow green cyathia and red flowers.
- Bonfire Euphorbia, Burgundy to fiery orange leaves and bright yellow cyathia and flowers
- Tasmanian Tiger Euphorbia, white and green variegated foliage with white cyathia and yellow flowers.
At Martin Garden Center we tend to have perennial Euphorbia stocked at all times but not all varieties are available throughout the seasons.