The genus euphorbia is an absolutely enormous botanical genus that consists of over 2000 members. Though you may not know them by their latin name, euphorbiaceae, you’ve certainly seen members growing in gardens, or sold commercially around Christmas time.
The common name for euphorbia species is spurge. “That’s a strange name” you may be thinking, but this name derives from the Middle English term, “espurge”, which means to purge. This is in reference to the milky sap that was traditionally used as a purgative.
Spurge plants are highly valued both ornamentally and as landscape plants. They are incorrectly referred to as cacti, though they have similar adaptive characteristics. These characteristics, like drought tolerance and heat tolerance, are part of their value.
Resiliency, striking growth patterns, and unique flowers are only a handful of the reasons why this wonderful flowering plant should be the next member of your green space. Keep reading to learn more!
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What do Euphorbia Plants Look Like?
With some many members in their genus, euphorbia plants come in many different, shapes, sizes, growth patterns, and flower types.
Members will exist either as an annual plant (experiencing their entire life cycle within one year), biennial plant (experiencing their entire life cycle within two years), or a perennial plant (experiencing a flowering season year after year).
A very unique aspect of the euphorbia plant is the way that they produce flowers. What may appear as a flower head is actually something called a pseudanthium, which is a type of inflorescence.
A pseudanthium is a type of a flower head that is reduced down to purely the essential plant parts that are needed for sexual reproduction (a type of petaloid appendage).
They are borne either as a female flower, where they will be reduced to only a pistil, or as a male flower, where they will be reduce to only a stamen. They do not have any petals or sepals, but still appear as being flowers.
Instead of petals and sepals, they come equipped with structures that appear similarly, and still function in attracting pollinators with attractive shapes and colors.
Regardless of the flower structure, all euphorbia flowers will produce fruit in the form of a fleshy capsule. This seed pod will mature into a woody capsule that will eventually explode to disperse ovular seeds.
Depending on the growing location of the plant, a euphorbia will produce either evergreen leaves (persisting and remaining green all year long) or deciduous leaves (changing color and falling away each fall). Leaf color will slightly vary from species to species in different shades of green.
Leaves are borne in different arrangements: either oppositely arranged, alternately arranged, or in a very unique whorl pattern. Another word for this growth habit is fractal, which we see in plants like romanesco! They usually grow on the ends of stipules, and a leaf will be either smooth or covered in fine hairs.
Euphorbia plants take many different forms. They can grow anywhere from a woody shrub to a large tree. Many species grow as a type of succulent, either with smooth fleshy stems or thorny appendages. When species exhibit a succulent growth habit they are more commonly a short lived annual plant.
A common occurrence amongst species are their root system. They will commonly either have fine and tuberous roots, or thick and fleshy roots. Their root system helps them combat dry and hot conditions.
What are Some Euphorbia Species?
Poinsettia (Euphorbia Pulcherrima)
One of the most commonly known euphorbia species is the poinsettia (euphorbia pulcherrima). This shrub plant is most popularly bought around Christmas time because of their red and green color scheme.
Poinsettias are valued for their foliage, with brilliant red floral bract and large, deep green leaves. They have inconspicuous yellow flowers.
Crown of Thorns (Euphorbia Milii)
Also known as the Christ plant or the Christ thorn, the crown of thorns (euphorbia milii) is a plant well known because of the legend surrounding it. It is though that the crown of thorns was the plant worn around Jesus’ head during the Crucifix.
Though not the happiest of legends, this euphorbia species is still lovely as an ornamental house plant with spiny stems, fleshy and green succulent leaves, and small conspicuous bract flowers of pink, red, or white flowers.
Indian Tree Spurge (Euphorbia Tirucalli)
Also known as Aveloz, pencil tree, pencil cactus, or milk bush, the Indian Tree Spurge (euphorbia tirucalli) grows as either a small tree or a large shrub. It gets its name because of its pencil thick, succulent branches.
Sometimes growing to be over 7 metres in height, this succulent shrub produces very fleshy succulent twigs, ovular leaves that yellow and fall away early in the year, and lovely yellow flowers that are borne at the ends of their branches.
Euphorbia of the Ancients (Euphorbia Antiquorum)
Also known as antique spurge, Euphorbia of the Ancients (euphorbia antiquorum) gets its name from the traditional medicinal use of this plant in ancient times.
This succulent plant that produces smooth, green branches, smooth green leaves, but black and intimidating spines. Flowers are actually modified leaves shaped as cups to help attract pollinators, and they are usually yellow or pink flowers.
Snow on the Mountain (Euphorbia Marginata)
Snow on the mountain (euphorbia marginata) is an annual variety that grows in warmer weather regions. Growing to be about half a metre in height, this single stemmed plant produces bright green leaves with white margins.
Inconspicuous yellow flowers are borne at the ends of long stems and bloom very late in the year. They are not true flowers, and lack petals and sepals.
Candelabra Tree (Euphorbia Ingens)
Otherwise known as a Naboom tree, the Candelabra tree (euphorbia ingens) is a very tall succulent tree that can reach up to 8 metres in height!
This perennial euphorbia has thick trunks with deep fissures, and thin, upward ascending branches that give the tree the overall shape of a balloon. Small green or yellow flowers sit amongst the fleshy green leaves near the top of the crown.
Mediterranean Spurge (Euphorbia Characias)
The Mediterranean spurge (euphorbia characias) is a very stately and elegant evergreen subshrub. This plant produces spirally arranged, blue/green leaves at the ends of erect stems.
This variety is valued because it produces chartreuse flowers (similar to those of a bottle brush plant) that stay in bloom for many months of the year, starting in early spring.
Marsh Euphorbia (Euphorbia Palustris)
The marsh euphorbia (euphorbia palustris) is a herbaceous perennial plant that can grow to be about half a metre tall. They usually bloom from late spring and last through much of the year.
This upright, clumping, succulent euphorbia produces elliptic leaves at the ends of stems, accompanied by large, yellow/green, showy bracts.
Where is Euphorbia Native to?
With over 2000 members in the genus, euphorbias are native to many different places, and with very extensive growing ranges.
Most of the succulent varieties can be found growing wild in the most tropical areas of Africa. Other varieties grow naturally in places like Madagascar, the Pacific Islands, Australia, and the warmer regions of Europe and Asia.
What are the Growing Conditions of Euphorbias?
Growing euphorbia can be accomplished by anyone, not just green thumbs! Whether they are growing as herbaceous perennials, fleeting annuals, perennial herbs, or anything else, these plants will bring glory to your garden. All you need to know is how to keep them happy!
Though euphorbias aren’t particularly picky about their soil type, there are some things to keep in mind when planting your own specimen.
It is best to plant a euphorbia in sandy soil or low fertility soil. This is because very fertile soils will cause too much growth, and they can easily spread beyond their boundaries.
The main characteristic necessary for a happy plant is well drained soil. Even if it is completely dried out, euphorbia roots require plenty of aeration.
The vast majority of euphorbia species are sun loving. This means that they require a minimum of 6 hours of full sunlight throughout the day. There are a small handful of varieties that prefer to exist in partial shade.
Since euphorbias are accustom to living arid, desert landscapes, they are completely drought tolerant once they’re established.
If it’s being grown as a cultivated plant, it can exist on natural precipitation alone. If it’s growing as an indoor plant, water in the same way you would a succulent — sparingly, and only when leaves begin to dimple.
One of the main reasons why euphorbia plants are so valued is because of their tolerance to both high temperatures and to drought. They can exist in USDA zones 6 through 9.
Incorporating an organic compost to an establishing euphorbia plant will help it along its first growing season, but after that it does not need fertilizer at all.
As previously mentioned, living in soils that are too fertile can result in a plant with an uncontrolled growth habit that quickly spreads beyond intended boundaries.
If there were ever a plant that loved to be pruned, it’s the euphorbia. These guys really benefit from hard pruning.
First thing is first, remember to wear gloves when pruning euphorbias. They secrete a white, milky sap that is a severe irritant to skin, so make sure to glove up!
They can be cut back hard right after flowering, and you can prune away at least a third of the flower stem.
This severity of pruning helps keep the plant tidy and healthy, prevents flowers from free seeding, and encourages a lovely explosion of fresh foliage.
At the end of the day, euphorbia plants are wonderfully resilient and easy to care for — that is, if you have experience caring for cacti and succulents.
Remember that they do not function like a regular garden plant would, and that they pretty don’t need to be cared for.
Them main things to remember are that euphorbias are intolerant to water logged soils, intolerant to freezing, and that’s pretty much it!
How is Euphorbia Used?
With so many different species and cultivars to choose from, you are guaranteed to find a euphorbia plant that will perfectly suit your property.
They are often used as feature house plants, as border plants in evergreen gardens, statements plants in rock gardens, and an addition to help keep a winter meadow green.