Chinese milk vetch

Value to bees

Nectar

Very high

Pollen

High

As a honey crop

Major honey crop — yields a surplus in good years

Which bees, and why

Colonies build enormously on it before moving north for the later crops. The shallow florets are accessible to honey bees, unlike the deeper legumes.

Small shallow pea flowers with reachable nectar, workable by short-tongued bees.

Worth knowing

Very high nectar delivered at vast scale in early spring, and the anchor of migratory beekeeping across southern China.

Flowering

In flower

March to May (northern hemisphere)

Three to five weeks, ending abruptly when the fields are ploughed for rice. The flow is terminated by a tractor rather than by weather.

When nectar flows

Generous and concentrated. Whole valleys of paddy come into flower at once, which produces an enormous short-lived resource.

Year-to-year variation

Historically among the most dependable major flows in Asia, and now declining with the acreage as green manure has given way to fertiliser.

What it does to the honey

Produces a very pale, soft, mild honey with a faint green-bean freshness — unassuming, and made in enormous quantity.

Growing it

Conditions

Grown as a winter cover crop in paddy fields; it needs the moisture and the mild winter of a rice-growing climate.

Size

15-40 cm, sprawling.

Native range

China and Japan, cultivated across east Asian rice-growing regions.

Suits

Farm scale, Meadow or wildflower area

• Not a garden plant outside east Asia, and included here because it is one of the largest bee plants in the world.
• Its decline is a straightforward illustration of how agricultural chemistry removes honey crops: fertiliser replaced the green manure, and the flow went with it.

What it looks like

A low sprawling annual with pinnate leaves and rounded heads of small pink-purple pea flowers held just above the foliage.