Ribbed melilot

How to recognise it

Growth habit

Biennial: in the first year a low, leafy plant, in the second year upright, much-branched stems of 0.5–1.5 m.

Leaf

Three-part, like clover; the leaflets are oblong, 1–3 cm, with finely toothed edges.

Flower

Small, lemon-yellow pea flowers of 5–7 mm in long, slender, loose spikes up to 10 cm, from the leaf axils. Sweetly scented. From June to September.

Fruit/Seed

Small, hairless pods of 3–5 mm, ribbed crosswise, brown when ripe, with 1–2 seeds.

Roots

A deep taproot with root nodules, in which bacteria fix nitrogen.

Confusion with

Tall melilot has hairy pods that turn black and more often grows in damp places. White melilot has white flowers. Common bird’s-foot-trefoil and black medick stay much lower and have flowers in heads.

Flowering: June–September · Pruning: March and September

Why grow it?

• One of the best forage plants for bees: honeybees, bumblebees and many wild bees visit the flowers all summer.
• Hoverflies, butterflies and wasps come for the nectar too.
• Like other legumes, it fixes nitrogen from the air with nodules on its roots: a true pioneer on bare, poor ground.
• Flowers for a long time, from June to September, and gives a sunny wild patch or verge an airy yellow haze.
• Dried, it smells of hay and vanilla; it used to be laid among the linen.

Ribbed melilot: where does it grow best?

• In the wild: verges, railway embankments, dykes, quarries, waste ground, port areas and other stony, open places.
• Full sun; in shade it stays floppy and flowers poorly.
• Dry to moderately moist, free-draining soil, often chalky, sandy or stony; poor to moderately rich.
• In the garden: at the back of a sunny wild-flower meadow or wild patch, on a bank, a stony spot or in a bee garden.

Goes well with

• Wild marjoram: Another top plant for bees, on the same dry, chalky soil.
• Viper’s-bugloss: Blue flowers next to the yellow spikes, in dry, stony places.
• Wild carrot: White umbels in the same sunny wild patch.
• White melilot: Flowers at the same time in white; together they draw even more bees.

Ribbed melilot: when and how to plant it?

1. Buy seed of native origin from a nursery or wild-flower seed supplier.
2. Sow in April–June or in September, thinly and shallowly, on loose, open soil in full sun.
3. The seed has a hard coat. Sown in autumn, winter softens it; in spring it helps to rub it lightly with sandpaper first.
4. Thin or plant at 40–50 cm. In the first year you will only see leaves; flowering follows in the second year.
5. Sow two years running, so you have flowering plants every year.
6. Never dig up plants from the wild: with their deep taproot, they do not transplant well.

Care

Watering

Only when sowing and for young plants. After that it copes even in dry summers, thanks to its deep root.

Feeding

Do not feed: it takes its own nitrogen from the air, and on rich soil it goes floppy and falls over.

Mowing

In a wild-flower meadow, mow in September–October, after the seed has set, and remove the cuttings. That way it can reseed itself each time.

Self-seeding

Let most stems drop their seed: as a biennial, it only survives through seed.

Support

In a windy spot the tall stems may fall over; among other tall wild plants it stands firmer.

Tip: Sow two years running, or let seed fall every year: because it is biennial, you will then have flowering plants every year instead of every other year.

Pruning and mowing

Pruning months: March and September.

When: Clear the old stems in March; in September, mow or cut off faded spikes if you wish.

How:

• After flowering, let most of the seeds ripen and fall.
• For fewer seedlings, cut off some of the faded spikes in September before they ripen.
• Leave the dead stems until March: small insects overwinter in them and birds search them for food.
• In March, cut or mow the old stems just above the ground.

Caution: After flowering in its second year, the plant dies: that is normal, not a disease.

Pruning: when and how · Pruning calendar and basic rules

Propagation

Seed

In August–September, strip the ripe pods, dry them and sow in autumn or the following spring. The seed stays viable in the soil for years.

Self-sown seedlings

Let the plant reseed itself; seedlings appear around the old plant.

Ribbed melilot: how does it get through the winter?

Hardy to −30 °C.

• First-year plants overwinter with a thick root and buds at the base; in spring they shoot up.
• Second-year plants die after flowering; the dry stems stay standing and give shelter.
• Fully hardy, to −30 °C; the seed survives in the soil for years.

Diseases and pests

• Falling over: On soil that is too rich or in shade the stems go floppy. Choose a poor, sunny spot.
• Gone after two years: Normal for a biennial. Let seed fall or sow some more.
• Too many seedlings: It can self-seed freely on bare soil. Weed out unwanted seedlings while they are young.
• Leaf weevils: Small weevils bite half-moons out of the leaf edges. Harmless to the plant; leave them be.

Through the year

• March: Cut down old stems. Second-year plants start into growth.
• April: Sow on open soil in full sun.
• May: Thin seedlings to 40–50 cm.
• June: First flowers on second-year plants.
• July: Full flower. Bees and bumblebees on the spikes.
• August: Flowering. First pods ripe. Pick spikes to dry for their scent.
• September: Last flowers. Collect seed. Sow. Mow the meadow.
• October: Leave the dead stems standing.
• December: Dormant; first-year plants overwinter with buds at the base.

Did you know?

• In the 1920s, cattle in North America died of bleeding after eating mouldy sweet-clover hay. Research into this disease led to the discovery of dicoumarol and later of warfarin, first used as a rat poison.
• The name Melilotus comes from the Greek meli, ‘honey’, and lotos, a name for clover-like fodder plants.
• The smell of hay comes from coumarin, the same substance that gives dried sweet woodruff its lovely scent.