How to Grow and Care for ‘Purple Emperor’ Sedum (Stonecrop)

Hylotelephium (syn. Sedum) ‘Purple Emperor’

‘Purple Emperor’ is a regal-looking, hybrid sedum cultivar with dark violet foliage and pinkish-red blooms.

Violet leaves aren’t too common in the plant kingdom, and ‘Purple Emperor’ creates a striking visual contrast with the typically green leaves of surrounding plants.

Growing 12 to 18 inches tall with an equal spread, ‘Purple Emperor’ has fleshy, succulent foliage.

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It has an upright, yet mounded growth habit that manages to keep pretty tidy, in spite of its densely-growing shoots.

In our guide to growing stonecrop, we cover broad cultivation requirements for these plants.

This guide concentrates on how to grow ‘Purple Emperor’ in your landscape.

Here’s what we’ll be discussing:

A member of the Crassulaceae family of stonecrops, ‘Purple Emperor’ is a hybrid perennial sedum that’s hardy in USDA Hardiness Zones 3 to 9.

Many botanists consider it to be a member of the distinct Hylotelephium genus, while others still include it as part of the Sedum genus.

Persisting until mid-fall, these blooms are especially attractive to pollinators like butterflies and bees.

‘Purple Emperor’ was awarded the Royal Horticultural Society’s prestigious Award of Garden Merit in 2006.

You can grow ‘Purple Emperor’ in a container, in beds and borders, or with others of its kind as a mass planting. The blooms are ideal for cut or dried flower arrangements.

How to Grow

Full sun is best for ‘Purple Emperor,’ along with lean, well-draining soil that has a pH of 6.0 to 7.0.

You can get away with planting in part shade if your region is very hot during the summer months, but in general, full sun will ensure an abundance of flowers.

Ideal ingredients for well-draining and lean soil include coarse sand and fine gravel, or even perlite if you’re going with a soilless medium for growing in a container.

Where to Buy

‘Purple Emperor’ should be fairly easy to find in your local plant nursery or garden center.

‘Purple Emperor’

If you prefer to shop online, you can find plants available at Nature Hills Nursery.

Maintenance

Removing spent blooms can help to tidy up the plant, though leaving them in place can provide texture in the fall and winter garden.

Dead, diseased, or damaged leaves and stems should be pruned as you notice them to prevent them becoming a drain on the plant.

Propagation

Since it’s a hybrid cultivar, if you collect seeds, there’s no guarantee that they’ll grow true to the parent.

You can propagate via stem cuttings or purchase transplants from the nursery.

From Cuttings

You can take stem cuttings in spring or summer. Here’s how:

1. Choose a healthy stem and cut a four- to five-inch length.
2. Strip the lower leaves, so just two to three remain at the top of the cutting.
3. Set the stem in a dry location for two to three days so the cut end can callus over.
4. Prepare pots filled with well-draining soil.
5. Plant the cutting about two to three inches deep and set it on a sunny windowsill.
6. Maintain even moisture but don’t allow the potting medium to become waterlogged.

After two to three weeks, the cutting should have developed roots and it can be transplanted into the garden or into a permanent container.

Transplanting

Make sure you transplant when all risk of frost has passed. It’s best to set plants out in spring so they have plenty of time to become established before winter rolls around.

Set the root ball in the hole and backfill with soil. Water in the transplants.

Pests and Disease

With its tough, succulent leaves, this variety is resistant to both deer and rabbits.

Scale, mealybugs, and black vine weevils are critters that may cause problems, though.

Scale and mealybugs will both suck sap from leaves and stems while also excreting honeydew, which can weaken individual leaves and the plant as a whole.

To control these pests, you can blast them off of plant surfaces with strong sprays of water.

Alternatively, you can use rubbing alcohol to kill them – to do so, dab them with a cotton swab that’s soaked with a 70 percent solution of rubbing alcohol and water.

Black vine weevils are two pests in one, really. The immature grubs munch on the roots, while the adult beetles will consume the leaf margins at night.

To control the larvae, you can apply species of beneficial nematodes like Steinernema kraussei and Heterorhabditis bacteriophora to the soil.

To combat the leaf munching from the adults, you can use pyrethrin sprays on the foliage while the adults are feeding in late spring to early summer.

Don’t forget about slugs and snails, either. These pests will chew irregularly-shaped holes in foliage and sever stems.

Powdery mildew will coat infected leaves with powdery white mycelium and spores, which can weaken plants as well as interfere with photosynthesis.

Leaf spot can be caused by various genera of fungi like Cercospora, Colletotrichum, or Septoria.

The spots eventually develop into necrotic patches. Treat leaf spot with a fungicide like copper.

Empurple Your Garden

Fun fact: empurple means to “make purple.” Which you can do to your landscape with ‘Purple Emperor!’ How ’bout that?

With what you’ve learned, you can add some violet to your garden alongside the green.

Add some orange via pumpkins or nasturtiums on top of that, and you’ve got a nice garden of secondary colors.

Still have questions? Have some awesome pictures of your own ‘Purple Emperor’ plants to show off? Visit the comments section below.

And to learn more about growing stonecrop plants, have a read of these guides next: