Spring and Bunching
Spring (or salad) onion seed can be sown in open ground or containers at three week intervals from the beginning of April to early June to give a continuous supply throughout the year.
Japanese bunching onions can be grown and used just like spring onions.
These are a different species, and the main difference is, they produce thick white or red stems rather than bulbing up like spring onions.
Bunching onions tend to be easier to grow than spring onions, and have a longer season and are usable after only six weeks from sowing.
Some cultivars will overwinter and produce stems in spring.
To get an early crop, sow a pinch of seeds in pots or cell trays to grow on undercover.
Plant out* mid to end of April under cloches when the weather and ground temperature is warmer.
*Spacing is not critical.
Seedlings that are planted close together usually produce smaller bulbs than those thinned out to grow singly.
Sow seed thinly in drills 12mm (1/2") deep in rows 300-400mm (12"-16") apart.
Make successional sowings every two or three weeks.
Rake in a top dressing of a balanced fertiliser at a rate of 50gms (2oz) per sq m. prior to sowing.
If ground is relatively dry soak bottom of drill prior to sowing.
For pencil-thick plants, gradually thin the rows of seedlings out until you end up with plants approximately 20mm (¾") apart.
Crops take around 10 weeks to harvest.
Lift onions as required.