Valerian

Valerian is a tall perennial whose root has been used as a sleep remedy since ancient Greece. In early summer it sends up big, airy clusters of tiny white to pale pink flowers with a sweet, vanilla-like scent that drifts across the garden.

The root smells very different: strong and musty, like old socks. Cats love it almost as much as catnip.

It came from Europe and Asia as a garden herb and has escaped into damp meadows, ditches and roadsides. In some places, including parts of the Great Lakes region, it's spreading fast.

How to spot it

• Leaves are divided into 7 to 25 narrow, toothed leaflets in a single row on each side of the stalk. They grow in pairs on the stem.
• Flowers are tiny, white to pink, in rounded, branching clusters at the top of the plant.
• Stems are tall, grooved and hollow, often 1–1.5 m.
• The scent of the flowers is sweet. The root smells strong and musty.

What it's good for

Valerian root is one of the best-known herbal remedies for poor sleep and anxiety. People dry the root and use it as a tea, tincture or capsule. Studies are mixed: some find it helps people fall asleep a little faster, others find no effect.

Dig roots in autumn from plants at least two years old. Be ready for the smell.

Don't confuse it with

From a distance, its white flower clusters on tall stems can look like poison hemlock or water hemlock. Those are in the carrot family: their flowers sit on spokes that spread from a single point, like an umbrella, and their leaves are finely cut. Valerian's flower clusters branch, its leaflets sit in one simple row, and its flowers smell sweet.