Mention the word “ascot” and a silky men’s tie worn by the upper crust of European society comes to mind. Today, however, I want you to associate the name with Ascot Rainbow, an evergreen perennial euphorbia capturing the imagination of the gardening world.
Botanically speaking, Ascot Rainbow is known as Euphorbia martinii. It is native to Australia, where the name Ascot is associated with an old, wealthy suburb of Brisbane. In truthfulness it is known as a spurge, which we most often associate with a host of terrible weeds. Ascot Rainbow, however, is worthy of royalty.
First, know that the plant is a perennial in zones 5-9, which means much of the country can enjoy the incredible texture this plant offers the landscape border. It reaches 20 inches tall with an equal spread. Where I am plant-lusting it now is in mixed containers as a partner to other cool season flowers like pansies, violas, kale and snapdragons. There is something about the plant that fixates my attention. The foliage is deep green with golden margins in the cool season.
The drop in temperature also fires it up with shades of red, pink and even orange. In spring and summer, the bloom is among the most unique as it features lime-colored bracts and red centers.
The Ascot Rainbow is drought tolerant, and that will thrill gardeners everywhere. It is also rabbit and deer tolerant. As you would expect from a Euphorbia from Australia, it needs good drainage and thrives in full to partial sun.
In a way I think of the Ascot Rainbow as an evergreen perennial, but it helps in your design to consider it more as a dwarf shrub and plant a cluster of three with ornamental grasses and perennials like purple coneflowers, rudbeckias and blue salvias. It fits this type of border perfectly and adds a great deal of interest from leaf texture and bloom.
If you are the lucky gardener with rocks or a slope, then let Ascot Rainbow dazzle all your visitors as you combine it with other drought tolerant, tough-as-nails flowers. But you will treasure it as the thriller plant in cool season mixed containers. It naturally forms a rounded ball, and a layer of pansies, including some trailing in front, is most picturesque. But if your container is large enough, then your options are limitless as you can use it with tall snapdragons and dianthus and blue-leafed kale, which contrasts with Ascot Rainbows golden variegation. You are the artist.
Maintenance is easy. Remove old bloom stalks in late summer or fall all the way to the ground. As with other spurges we grow, this one too is not to be eaten, but enjoyed for the beauty and texture it offers your garden.