The Gemma onion sets produce round, firm bulbs with shiny outer skins. Their flesh is white, crisp and highly aromatic, with a moderately pungent flavour. They are highly productive and store well.

Plant 3–4 cm deep. For spring onions, leave 8–10 cm between sets and 20–25 cm between rows; for dry onions, the respective spacing is 12–15 cm and 20–25 cm. Water...