Green manure

Definition

Phacelia, buckwheat, mustard, sweet clover and Chinese milk vetch are all grown to improve soil, suppress weeds or fix nitrogen, and all produce honey as a by-product. Chinese milk vetch is the largest example: sown into rice paddies over winter and ploughed in before the rice goes down, its few weeks in flower once supported one of the biggest honey flows in Asia.

Where the word gets used loosely

These honeys are hostage to agricultural chemistry rather than to weather. Chinese milk vetch honey has declined sharply as fertiliser replaced green manure, exactly as sainfoin honey vanished from Europe a century earlier for the same reason.

Honey records that discuss this

• Sulla honeyVery delicate and clean, with a soft almond-and-fresh-grass note and almost no aftertaste.
• Phacelia honeyMild, clean and gently floral with a faint herbal freshness — an easy honey with no rough edges at all.
• Milk vetch honeySoft, mild and slightly floral with a faint green-bean freshness — an unassuming honey made in enormous quantity.
• Karanj honeyWarm and herbal with a faint bitterness and a light caramel base — mild by Indian standards and more interesting than its modest reputation suggests.

Plant records that discuss this

• BuckwheatGenuinely useful as a late-summer gap filler, and its speed from sowing to flower makes it one of the few forage plants that can be deployed tactically within a single season.
• PhaceliaOne of very few plants rated top for both nectar and pollen, delivered late in the season when both are scarce. That combination is why it appears in nearly every agri-environment seed mix in Europe.
• Chinese milk vetchVery high nectar delivered at vast scale in early spring, and the anchor of migratory beekeeping across southern China.
• KaranjA good nectar and pollen source at the thinnest point of the Indian year.
• Crimson cloverA good nectar and pollen source, and accessible to honey bees in a way that red clover is not.
• Fodder radishA generous late nectar and pollen source in arable country where autumn forage is otherwise nearly absent.