Epimedium grandiflorum, a ground cover plant that’s quite the stunner

Surprising flowers give Epimedium grandiflorum an uncommon name, “Bishop’s hat“, and this slow-growing perennial will, in time, provide you with an abundance of flowers.

Epimedium grandiflorum key facts

Botanical name – Epimedium grandiflorum
Common names – barrenwort, bishop’s hat
Family – Berberidaceae
Type – perennial ground cover

Height – 8 to 20 inches (20 to 50 cm)
Planting density – 6 to 8 plants per sq. yard (m²)
Exposure – shade to part shade

Soil – not chalky, cool, well drained
Blooming – April-May
Foliage – deciduous

A seemingly fragile elegance, gracious flowers, and a very long lifespan are certainly what gave Epimedium grandiflorum one of its foreign common names, that of “Fleur des Elfes“, or elvenbloom in French. Though it seems frail, it’s covertly a very resistant perennial. In the garden, it will grace your flower beds with magnificent blooms and the ever-changing colors of its foliage will enthrall you as seasons come and go.

Planting Epimedium grandiflorum

For it to grow well, barrenwort needs a proper growing environment:

• A growing space that isn’t in direct sunlight. Ideally, part shade. Even the dense, dark shade of forest underbrush is well suited to this plant.
• As for the soil, better if it’s a bit acidic, but neutral pH will also be fine.
• Soil should contain lots of organic material. For instance, if the soil of your garden is rather on the poor side in terms of nutrients, you’ll definitely have to add a portion of rich, well-decomposed compost or a sack of soil mix before planting.

The number of plants you’ll need at the start depends on how fast you want to reach the end result for your bed. Typically, around 6 to 8 specimens will do per square yard or meter. However, if you want to cover the ground faster (say within a single year), you can add more and even double this amount.

Smart tip : since barrenwort loves cool soil, applying mulch is a good idea when you’re done planting. It will help the soil store moisture. Use pine bark if you have access to it, since it will keep the soil somewhat acidic as it breaks down.

Caring for Epimedium grandiflorum

Regular maintenance for Epimedium grandiflorum is simple and you’ll only have two things to do:

1. Control watering in times of drought.
2. Cut the clump back before the blooming at the end of winter or at the beginning of spring. This will let the plant renew all its leaves and make it look great for the spring and summer.

Multiplying and propagation

The best way to propagate a clump of Epimedium grandiflorum is to split it apart. You can perform this in spring, but a better time is autumn since this raises the chances of the plant properly settling in. You’ll also save on watering since usually fall and winter are rainy. In order to do so, you must:

1. Dig the Epimedium clump out of the soil with a spading fork.
2. Break the clump up into several portions with a spade or an edge liner (half-moon). Choose a tool that’s sharp-edged and not too blunt.
3. Transplant the split portions as if they were brand new plants.

Diseases and pests

Epimedium grandiflorum is one of the hosts of black vine weevil, also called scientifically Otiorhynchus sulcatus. This insect will attack all parts of the plant: roots, leaves and root collar (the portion where the roots and stem join).

Diseases that might infect barrenwort are most often the one or the other type of mosaic virus.

Landscaping and pairing

Thanks to the fact that it tolerates shade, Epimedium grandiflorum is perfect to add flowers under forest cover or in a shaded growing bed. So any plants to pair with bishop’s hat must also do well in such shady, darker settings. Options that match this requirement very well are lungwort, bergenia, brunnera and also Omphalodes.

To add both height and a dramatic backdrop, taller ferns or species of Heuchera are also worth considering.

A few interesting cultivars

• ‘Lilafe’: grows about a foot tall (30 cm), a particularly vigorous and flower-bearing cultivar. Blooms are a rich purple-violet hue (shown below).
• ‘Nanum’: as the name suggests, the ‘Nanum’ cultivar is more compact than others on average. New leaves unfurl to reveal a bronze-like color at the beginning.
• ‘Red Beauty’: also bears abundant flowers. At the onset of spring, its flowers are a lighter violet hue than those of the ‘Lilafee’ cultivar.

Learn more about Epimedium grandiflorum

Identifying barrenwort

Leaves are heart-shaped, but somewhat lopsided, similar to those that are typical of the begonia family. Flowers are clustered in small numbers at the tips of long, delicate scapes, and they tend to face downwards with petals folded back, similarly to those of winter cyclamens.