Onion Harvest

I planted my heat-treated onion sets (Cupido F1 and Red Baron) on 19th March 2021. By 24th August, the leaves had flopped and were starting to yellow. We had eaten a few onions already but now it was time to dig up the remainder and cure them for winter storage. The soil was loosened with a garden fork before gently pulling up the onions. Any bulbs showing disease (white rot) or thick-necks (having bolted/flowered) were put to one side for immediate use as these will not keep. Carefully brushing off any soil and trimming excess foliage to about 25-30 cm (not roots), the bulbs were then placed on a wire mesh to dry in a covered area.

Cupido white/strong onion sets (250 g) were bought from D.T. Brown (£3.45) and contained approximately 70-75 sets. Sprouting was close to 100% and only two onions exhibited white rot (?) - see below - these were used immediately in a batch of cucumber chutney after cutting away the diseased parts.  

I estimated a yield of about 18 kg (40 lb) from the Cupido onion sets. Assuming these store well over winter, that puts a value of £0.19/kg on this crop. For comparison, Sainsbury's are selling large white onions at £1.58/kg and small organic onions at £1.67/kg. Or to put it another way, investing £1 in onion sets yielded £8 in onions for a six-month investment!

The Red Baron pack (250 g for £3.45, also from DT Brown) contained only 40 sets with, again, near 100% sprouting. Two onions bolted and developed a hard neck - see below - so they were used within a week.

The remainder were cured on a wire rack and undercover in preparation for winter storage. The Red Baron pack (£3.45/250 g) yielded about 9 kg of onions with a 'market' value of £0.38/kg. Sainsbury's are selling red onions for £2.33/kg or £2.50/kg for organic. The 'investment' return on growing red onions was, therefore, less than white onions but still a healthy 660%!!

Generally, I do not have too many problems growing onions. I use crop rotation (4-year) and a mesh insect barrier around the onion plot. Apart from adding homemade compost to the onion plot before planting the sets in March and fortnightly weeding sessions during the growing season, there is very little to do before harvesting in late summer/early autumn. In dry summers, like 2020, some watering is required but this has not been necessary in 2021 as we have had rain fairly regularly throughout the spring and summer.