Nobody’s perfect, and the same is true of garden plants. Part of the fun in gardening is to grow as many varieties as you can to learn their secrets. A few, though, like myrtle spurge (or donkeytail spurge; Euphorbia myrsinites), harbor some secrets you really don’t want to learn about firsthand – it’s better to hear them before you plant!
Myrtle spurge is a colorful, tough creeper for rock gardens and the front of borders.
Photo Credit: Gerald L. Klingaman
In summer, myrtle spurge forms a carpet of blue-gray foliage.
Photo Credit: Gerald L. Klingaman
But before I reveal what this plant’s hiding, it’s important to know that myrtle spurge is a pretty little beauty that can prove quite useful in the garden. This sprawling evergreen perennial belongs to the euphorbia family, and it’s great for rock gardens, Xeriscapes and at the front of the border. It grows about 8 inches tall and sends out sprawling branches covered with waxy, blue-gray leaves. The sessile foliage is only about an inch long and is tightly clustered down the stem in a beautifully congested spiral.
In early spring, small, yellow flowers appear in terminal clusters at the ends of branches. These petalless affairs are called cyathia, and they’re clustered inside a bowl-shaped structure consisting of two yellow, cup-shaped bracts. The cups are ¾ of an inch across, but they’re clustered together to form an inflorescence that’s 3-4 inches wide.
This easy-to-grow euphorbia just needs full sun and well-drained soil to grow beautifully in USDA hardiness zones 4-10. Myrtle spurge tolerates drought well during the summer and is well-suited to high pH soils, but good drainage is essential for winter survival.
The plant reseeds freely, but it’s never really weedy in a garden situation. It just pops up here and there among other plants. For the most part, myrtle spurge really only lasts long-term in dry perches where it gets the drainage it needs.
That being said, there are at least four Western states – Colorado, Oregon, Washington and Utah – that list this plant as being a noxious weed that’s escaped cultivation. That’s the first big secret behind myrtle spurge, so be wary of planting it where it’s proved problematic!
There’s also another secret to myrtle spurge you need to know: Like many of its euphorbia relatives, this spurge’s sap can cause extreme allergic reactions in some people (including me). Even though most people show little reaction to it (or if they do, they only develop a poison ivy-like rash), for sensitive individuals, contact can lead to anaphylactic shock!
Whether you’re allergic or not, it’s obviously not worth taking any risk, so always wear gloves when handling myrtle spurge, and wash your hands thoroughly afterward! I’ve now had three stressful encounters with Euphorbia sap, two resulting in emergency room visits. These were classic anaphylactic shock reactions which – trust me – are no fun, but compared with getting the sap in my eye, they were a cakewalk.
And yet, despite the sap risks, I still grow a number of euphorbias, including Euphorbia myrsinites – I’m just much more cautious when I work around them! As I said, using gloves when working around any of the ornamental spurges seems like a sensible precaution for all gardeners, even for those showing no indication of sensitivity.
So if you’ve got the courage and the right planting site, consider giving low-maintenance myrtle spurge a try. With just a bit of precaution, this easy-care perennial will add lots of color and texture to your garden – just be sure to handle it with care – and a good pair of gardening gloves!
