Medwyn Williams advises on planting shallots and onions for showing
David Lewis, by email
Medwyn says: For exhibiting shallots the traditional planting date used to be on the shortest day, December 21, and harvested on the longest, June 21, and this practice, to a certain extent, still holds good today. I normally try and get them in between Christmas and new year, planted up in 10cm (4in pots) or 9cm (3½in) pots. I use either Humax Original Multi-purpose compost or Levington M3, both are excellent for this job.
The pots will stay in a cold polytunnel until early to mid March when they'll be planted in their beds outdoors, provided the soil is in good condition. For the best results grow either 'Hative de Niort' or 'Aristocrat', as both are proven winners on the show bench. When exhibiting shallots there are normally two classes, one for ’shallots large exhibition’ and the other for ‘shallots pickling’.
Some growers grow their pickling shallots right through to harvest time in their 9cm (3½in) pots and they're then checked so they pass through a 30mm ring. This measurement is usually shown in the schedules as a ‘must’ and therefore has to be adhered to, otherwise you will receive the dreaded NAS card (not according to schedule). I've grown shallots in pots quite successfully for Chelsea and they were grown in 23cm (9in) pots, three to each pot.
They were started off in 9cm (3½in) pots and potted up later on into a stronger mix by adding some good quality top soil to the Levington M3. A 10 litre sieved potful to a 70 litre bag as well as 6oz of Nutrimate powder will give the compost a buffer and help carry them through until ready to harvest.
Keep them inside the tunnel until early May, at which point they can be moved outdoors, when each bulb would then be thinned down to leave three in each clump. You should be able to grow them singly in 3 litre pots but they might need some liquid feeding as they mature.