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Devil’s beard, the garden valerian

Clusters of small crimson flowers, likened by the botanist De Candolle to a red spearhead, rise on stems 24 to 40 inches (60 to 100 cm) tall from late spring to early autumn. Native to the Mediterranean, devil’s beard (Centranthus ruber) asks only full sun and poor, well-drained soil — give it that and it will even root in a wall crack.

Devil’s beard at a glance
Name Centranthus ruber
Family Caprifoliaceae (honeysuckle family), into which the Valerianaceae family was merged
Type perennial
Height 24 to 40 inches (60 to 100 cm)
Exposure full sun
Soil ordinary, or even poor
Flowering late spring to early autumn

Sowing and planting devil’s beard

You can start sowing devil’s beard at the end of winter or transplant seedlings purchased from horticulture stores in spring.

Sowing garden valerian

Garden valerian is sown right at the end of winter with a cover, or in spring directly in the ground, when the last frosts are past.

Devil’s beard needs sun to develop and bloom.

If you sow directly in the ground:

  • Break up the soil to lighten it up.
  • Broadcast sowing
  • Thin as soon as the first leaves appear to keep only the most vigorous seedlings every 12 to 16 inches (30 to 40 cm).
  • Water regularly with a fine drizzle.

Planting devil’s beard

Spring or fall are the recommended planting seasons for devil’s beard. Keep a distance of 12 inches (30 cm) between plants.

If you’re planting devil’s beard in spring, remember to water a bit more at the beginning.

  • No need to add soil mix because devil’s beard only has very limited needs.
  • Devil’s beard literally grows on all kinds of soil, sometimes even a crack in the wall is enough for it to take root.

Propagating devil’s beard

Devil’s beard is a plant that propagates naturally through its seeds, but it is also possible to perform crown division.

Divide only young, vigorous clumps of red valerian (Centranthus ruber): older plants develop a deep, woody taproot and resent division, so propagate mature specimens from seed or basal cuttings instead.

Lift self-sown seedlings while they are still small.

Sowing, planting or dividing: which route to take

Devil’s beard can be started from seed, bought as young plants, or lifted and split, and each route has its own season and spacing. The table below sets the options side by side so you can pick the one that suits your plot.

Sowing, planting or dividing: which route to take
Method When How Points to watch
Sowing under cover Late winter Sow in trays with a cover before moving plants out Seedlings need sun to develop and bloom
Direct sowing in the ground Early to mid-spring, once the last frosts are past Break up the soil, broadcast the seed, water with a fine drizzle Thin to one vigorous seedling every 12 to 16 inches (30 to 40 cm)
Planting young plants Spring or autumn Set plants 12 inches (30 cm) apart, no soil mix needed Spring plantings need a little extra water at the start
Crown division Autumn Split young, vigorous clumps Older plants form a deep woody taproot and resent division
Self-seeding Whenever flower heads turn fluffy The plant sows itself, seedlings can be lifted and moved Can become invasive, so pull unwanted seedlings while small

Whichever route you choose, full sun and a poor, free-draining spot matter far more than any extra attention.

Pruning and caring for devil’s beard

Devil’s beard is definitely an extremely easy plant that requires no care at all.

Devil’s beard is even considered an invasive plant, it makes sense to heed the cue and control its growth.

  • Cut back short in fall, once leaves have wilted.
  • No need to water devil’s beard, except perhaps if potted since potted plants are more vulnerable to drought.

Deadhead the faded flower heads before they turn fluffy, and you will both limit self-seeding and often earn a second flush of bloom.

Shearing the whole clump back by about half after the first flush keeps it tidy instead of leggy.

Pull unwanted seedlings while small; their taproot soon anchors deep in wall cracks.

For red valerian (Centranthus ruber), the Mediterranean species, skip fertiliser: it thrives in poor, well-drained soil, whereas rich feeding tends to produce soft, floppy stems and fewer flowers.

Diseases and parasites that attack garden valerian

Very easy to care for, it fears no disease or parasite.

However, if you detect a white layer or frost-like covering of the leaves, most probably powdery mildew is infecting it.

Red valerian (Centranthus ruber) thrives in dry, well-drained, even rocky soil, and waterlogged ground can rot its crown, while the plant itself is rarely troubled by serious pests.

Mildew takes hold mostly where clumps have grown dense and airless, so divide or thin crowded plants to let air move through the foliage.

Slugs and snails commonly damage soft young seedlings of many garden plants, and tougher mature growth is generally less vulnerable, though established plants are not guaranteed to escape grazing entirely.

All there is to know about devil’s beard

Red valerian, or Centranthus ruber, owes its name to the botanist De Candolle, who likened its flowers to a red spearhead (kentron means spear in Greek, and anthos means flower and ruber means red).

Native to the Mediterranean area, devil’s beard or garden valerian has the incredible capacity to grow in all types of soil, even the driest ones.

It can be found especially along the Atlantic coast.

Also, devil’s beard is often said to share the sedative properties of its cousin medicinal valerian. But take note that devil’s beard or garden valerian (red valerian) differ from medicinal valerian.

Important note: Garden valerian is related to the Valeriana family. A compound that is present in all of these plants is valproic acid, a soothing agent. It has been shown that ingesting it during pregnancy, especially the first trimester, resulted in more birth defects (1 to 2% more) in the children born. These include spina bifida, atrial septal defect (hole in the heart), hypospadias (an abnormality in the urethra in boys), polydactyly (extra fingers/toes), craniosynostosis and cleft palate. Do not use this herb while pregnant!

Smart tip about devil’s beard

Be aware that devil’s beard multiplies on its own very easily, and sometimes becomes invasive.

Red valerian decorating a green-wire fence
It roots even in wall cracks, needing no care

Image credits (edits Gaspard Lorthiois):
Pixabay: an anonymous photographer, Gabriele Lässer

Written by Gaspard Lorthiois | Loves helping out, especially when it comes to growing things. Worked in herbal medicine, runs a farm, and dabbles in tech. Master's degree and engineer.

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