Sourwood

Value to bees

Nectar

Very high

Pollen

Low

As a honey crop

Major honey crop — yields a surplus in good years

Which bees, and why

Worked hard by honey bees moved up the ridges for the flow, and by bumblebees, which handle the pendulous narrow-mouthed flowers more easily.

Small urn-shaped flowers hanging downwards — the same shape as blueberry and heather, and the same mild bias towards bees that can grip and hang.

Worth knowing

A serious nectar source with very little pollen to offer, which is a useful illustration of why the two are rated separately: sourwood feeds foragers superbly and contributes almost nothing to brood rearing.

Flowering

In flower

June to August (northern hemisphere)

Late June into early August, moving up the mountain with elevation. Three to four weeks at any one altitude.

When nectar flows

Needs moisture. A dry July suppresses nectar secretion sharply, and the difference between a wet and a dry summer is the difference between a crop and none.

Year-to-year variation

Strongly weather-dependent, and the resource itself is in slow decline as Appalachian clearings revert to closed canopy and land is developed.

What it does to the honey

Sourwood nectar gives the honey its anise-and-clove spice and its dry, faintly tannic finish. The spice register is shared, at a distance, with other Ericaceae honeys — heather and blueberry both carry an aromatic edge that separates them from ordinary floral honey.

Growing it

Conditions

Acid, well-drained soil, sun to part shade. Intolerant of alkaline soil, root disturbance and urban pollution, which is why it is rarely planted as a street tree despite its ornamental quality.

Size

8-18 m.

Native range

The eastern United States, from Pennsylvania to the Gulf, concentrated in the southern Appalachians.

Suits

Large gardens, Small gardens

• Slow-growing and worth the wait: few trees combine midsummer flowering, autumn colour and genuine forage value this well.
• It cannot compete once overtopped, so it persists on woodland edges, clearings and slopes rather than inside closed forest.

What it looks like

A slender tree with drooping branches, glossy leaves that taste distinctly sour when chewed, and long one-sided sprays of small white urn-shaped flowers in midsummer. It produces some of the most reliable scarlet autumn colour of any eastern American tree.