Red valerian is a common perennial wildflower found across most of Europe and North America.

Appearance
The plant can vary in size from a small herbaceous plant to a woody stemmed shrub. The size depends greatly on the quality of material it grows in and the length of time it is undisturbed. As it is perennial a small herb may turn into a large shrub over several growing seasons.
The leaves are generally 5–8 cm in length. Their form changes from the bottom to the top of the plant, the lower leaves being petiolate while the upper leaves are sessile. The leaves grow
The flowers can range from bright pink to purple and in some varieties white. Each flower is very small (approx 2mm diameter) but they grow clustered together in very large numbers. These clusters of flowers give the plant a very obvious and beautiful appearance.
Seeds are distributed on the wind. When fully developed they have feathery tufts that catch the wind and send the seeds great distances.
The flowers have a strong smell but cause a large amount of debate about what the smell is. I’ve found the following descriptions: like grape jelly, like vanilla, smells of sweat, rank and slightly fragrant. There is some evidence that the smell changes depending on the temperature and the time of day. So the same plant may smell different morning to evening or in cold to hot weather.
If you have any opinion put it in the comments.
Distribution
Red valerian is native to the Mediterranean region but is now naturalised in France, Australia, Great Britain, Ireland, Isle of Man and the United States mostly due to garden escapes.
It was introduced into UK gardens from the Mediterranean before the 1600s. This plant soon escaped and became naturalised in the wild.
As it grows and spreads so well it can end up being regarded as a pest. In fact it is listed as a NEMBA 1b invasive in the Western Cape, South Africa.
Habitat
Red valerian can be found almost anywhere below 200m. It is found growing on waste ground and road edges especially where the ground has been disturbed.
The RHS give it a hardiness rating of H5 which means:
As it is able to tolerate very alkaline soil conditions, it can grow and in many cases thrive in the lime in mortar. This allows Red valerian to grow in old walls in Italy, southern France and south-west UK.

Uses
Pollinators
It is known to attract insects and it is a good source of nectar from May to October for bees, butterflies, hoverflies and moths like the Hummingbird hawk-moth.
It is used as a food plant by the larvae of some moths including the angle shades.
Medical
The flowers, young shoots, roots and soft young leaves of Red Valerian are used in a folk remedy for cold, flu, or cough although they almost certainly don’t work.
Red valerian is related to the Valeriana family. Inside all these plants is valproic acid, a compound that helps relax.
It has been shown that eating any during pregnancy, especially at the beginning, resulted in more birth defects (1 to 2% added risk) in the children. These include spina bifida, atrial septal defect (a hole in the heart), hypospadias (in boys, an abnormality in the urethra), polydactyly (extra fingers/toes), craniosynostosis and cleft palate. Do not use this herb while pregnant or if hoping to be!
Lastly, red valerian is often said to share into the sedative properties of its cousin medicinal valerian. This again has not been proven and there is no proof red valerian has the same medicinal compounds as valerian.
Food
The leaves and buds of the plants can be used as a salad but are bitter and an acquired taste. They can be boiled to make soup which helps to reduce the bitterness.
Very young leaves are boiled in butter in France and Italy again helping to reduce the bitterness.

Growing
Plant seeds in the ground or in a tray at the end winter / early spring.
When the first leaves appear thin the plants leaving only the strongest.
If grown in a tray transfer straight into the ground leaving gaps of at least 30cm around each plant.
If grown in the ground choose the strongest plants and thin out leaving 30cm around each plant.
Take care when watering when the plants are young as the roots are easily disturbed.
Red valerian is tolerant of poor soils so there is no need to add fertiliser or soil improver.
You can cut off old flower heads but only for aesthetic reasons. It won’t improve the plants performance.
Cut the plant back short in the autumn.