Clusters of otherworldly chartreuse flowers hover above many other perennials just emerging from winter, bringing much-needed color and nectar for hungry pollinators.
But their flowers are just one of the many reasons they’re a staple in my zone-9 garden.
They’re also extremely drought and heat-tolerant, surviving on very little water even during the hottest summer months (and where I live, it’s HOT. We just had close to 30 straight days of triple-digit temps!)
One crucial aspect to remember is that most euphorbias are very sensitive to over watering and wet-feet. It’s vital that they have fast drainage to prevent root rot, which is the #1 cause of death.
If you think your soil has too much clay, I’d recommend throwing a few handfuls of garden grit in the bottom of the hole (click here to see what I use).
Below are some of my favorite varieties of euphorbia and the different ways I design with them.
In my book, Refresh Your Garden Design with Color, Texture and Form, I write a lot about using a plant’s subtle details to create unusual color echoes in the garden. Euphorbias are some of my favorites to use for this purpose.
Another elusive element in the garden is visual motion. I’m not talking about literal motion, like swaying grass on a windy day, but a plant that gives the illusion of movement without any breeze whatsoever
The Ascot Rainbow Spurge is a striking perennial plant admired for its colorful variegated foliage. While its vibrant leaves often steal the show, a closer look reveals the integral role played by its roots and stems. In this article we’ll explore the anatomy and functions of these two key plant parts that support the health and growth of Ascot Rainbow Spurge.
An Overview of Ascot Rainbow Spurge
Before diving into the roots and stems let’s briefly introduce the Ascot Rainbow Spurge. This plant, botanically called Euphorbia x martinii ‘Ascot Rainbow’ is a hybrid between the Mediterranean Spurge (Euphorbia characias) and the Wood Spurge (Euphorbia amygdaloides).
Native to France, Ascot Rainbow Spurge was first discovered in the late 1800s. It’s a bushy perennial that reaches 1-3 feet tall and 1.5-2.5 feet wide. The leaves are green variegated with shades of yellow, cream, and pink that become reddish-orange in fall. Small yellow flowers bloom in spring but they are rather insignificant compared to the colorful foliage.
This low-maintenance plant thrives in full sun to partial shade and tolerates drought, heat, and poor soils once established. Its vibrant hues and compact form make it ideal for containers, borders and rock gardens.
Now let’s take a closer look at the roots and stems that support this beauty.
The Extensive Root System
Though hidden underground, the roots are the foundation of the plant. The Ascot Rainbow Spurge has an extensive fibrous root system that spreads out shallowly below the soil surface.
The key roles of the roots include:
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Anchoring the plant: The wide network of roots anchors the plant firmly in the ground. This prevents uprooting from winds or heavy rain.
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Absorbing water and nutrients: The fine, hair-like roots efficiently absorb moisture and dissolved minerals from the soil.
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Storing food reserves: The roots store carbohydrates and proteins that the plant can draw upon when nutrients are scarce.
Proper root growth is vital for the health and vigor of Ascot Rainbow Spurge. Here are some tips for healthy roots:
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Prepare the soil with compost or peat to improve drainage and nutrition.
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Water deeply and infrequently to encourage deep root growth.
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Avoid disturbing the roots when transplanting and prune them if getting pot-bound.
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Mulch around the plant to maintain consistent soil moisture and temperature.
The Branching Stems: Conduit and Support
Branching upright stems give structure and support to the Ascot Rainbow Spurge. The stems also serve as conduits for transporting water, nutrients, and sugars.
Here are some key functions of the stems:
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Transport: The xylem and phloem tissues transfer water, minerals, and sugars between the roots, leaves, and other parts.
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Photosynthesis: The green stems contain chlorophyll and can perform photosynthesis.
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Support: The sturdy stems hold up the foliage and flowers above the ground for maximum sun exposure.
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Structure: Branching provides a nice rounded shape and facilitates bushy growth.
To promote healthy stem growth:
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Pinch or prune stems to encourage bushy, compact growth.
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Stake tall stems if needed to prevent breakage.
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Remove dead or damaged stems to maintain vigor.
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Ensure proper sunlight, water, and nutrition for strong stems.
Caring for the Roots and Stems
Caring for both the roots and stems is key to growing a thriving Ascot Rainbow Spurge plant. Here are some tips:
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Select a site with full sun to partial shade and well-draining soil.
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Water deeply to soak the entire root zone then let the soil dry out between waterings.
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Apply a balanced fertilizer in early spring to provide nutrients.
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Prune leggy stems in late winter to maintain a compact shape.
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Mulch around the plant to regulate soil temperature and moisture for the roots.
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Stake tall stems to avoid damage by wind or rain.
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Check regularly for pests or diseases and treat promptly if found.
The vivid foliage of Ascot Rainbow Spurge catches the eye, but the real work happens underground and inside the stems. Strong roots nourish the plant while the stems transport nutrients and provide support. Proper care of both organ systems is needed for the plant to thrive. Paying attention to the roots and stems along with the colorful leaves results in a healthy, floriferous specimen that brightens up any garden.
Euphorbia amygdaloides ‘Charam’/’Red Wing’ zones 7-9
An incredible variety for the front of the border is ‘Charam’ (also sold as ‘Red Wing.)
It grows to a tidy 2’x2′ mound with very compact blooms, but my favorite quality is the contrasting red stems.
I LOVE the bright green and deep red combo with the blue-ish tones in the foliage. A must-have, for sure.
Euphorbia ceratocarpa, zones 8-10
While this variety’s foliage isn’t maroon, blue, or even variegated, I decided to put it in this category because of its fresh and bright green color (it’s the oversized plant with the acid-yellow blooms behind the brick wall.)
I love how the chartreuse flowers contrast with the burgundy foliage of the Japanese maple. (click here to read about the transformation of this area of my garden.)
It’s hands-down my very favorite euphorbia of all, not only because it’s perfect for waking up a hot and tired garden but because it is the longest blooming euphorbia I’ve ever seen.
More often than not, I’ll still have flowers on this plant in December!
It’s a biggie, quickly growing to an impressive 5’x5’ so make sure you give it enough room – the middle or back of the border is ideal.
The foliage and flowers of the e. ceratocarpa are looser in form than some of the other varieties, giving it a light and airy quality.
The only downside is that it’s virtually impossible to find in the nurseries.
But luckily, you can easily propagate it via cuttings or by transplanting the occasional seedling that might appear.
What an Ascot Rainbow Euphorbia Look Like in a Landscape & at Maturity
FAQ
How deep is leafy spurge root?
How big does Ascot Rainbow Euphorbia get?
How do you transplant ascot rainbow Euphorbia?
Do you cut back Euphorbia ascot rainbow?
What is a ‘Ascot Rainbow’ spurge?
Never fear ‘Ascot Rainbow’ Spurge is here. Also known as Euphorbia martinii, this is a low growing evergreen subshrub (20 inches in height) that looks stunning in masses. This plant has an upright bushy habit with creamy green and white variegated leaves. The top of each growing tip has a tinge of magenta pink that gives off a tropical vibe.
Can Ascot Rainbow spurge grow in shade?
The Ascot Rainbow Spurge prefers to grow under the full sun, particularly when grown in the cooler USDA zones. For the warmer zones, it grows optimally in partial shade. However, be sure to protect the plant from the harsh rays of the afternoon sun. Moreover, this plant grows well in USDA hardiness zone 5 to 9.
Do spurges ‘Ascot Rainbow’ need a lot of water?
This dwarf hybrid grows well in containers and stands out in mixed borders. Spurges ‘Ascot Rainbow’ needs regular watering about once a week, especially during growing seasons. The plants don’t need great amounts of water during temperate environmental conditions, but during hot summer days they need as much water as any other plant.
When does Ascot Rainbow spurge Bloom?
The bloom time or growing season of this plant is typically between July and September. The Ascot Rainbow Spurge prefers to grow under the full sun, particularly when grown in the cooler USDA zones. For the warmer zones, it grows optimally in partial shade. However, be sure to protect the plant from the harsh rays of the afternoon sun.