I was on some allotments at the weekend and was struck how bare and scruffy they look at this time of year. We've passed the Spring equinox, but seedlings…
When growing this species, sow the seeds about 1/2inch (2cms) deep in drills. Make sure you keep the soil moist and remove weeds carefully to avoid damaging the tender roots of the onion plants.
They grow best in rich, well-drained soil, in full sun.
You can harvest them when the tops turn yellow and start to fall over. Keep the bulbs dry and harvest after several days of ripening time. Harvesting may start in late summer and end in early autumn.
This crop has a minimum growing temperature of 4C and a maximum growing temperature of 30C; the optimal growing temperature is between 12C and 25C.
As with all vegetables, it is good practice to rotate crops so as to avoid build-ups of pests and diseases.
Fairly easy to grow.
By seed or by specially heat-treated sets.
Pests, diseases or disorders
Onion fly and fungal diseases.