The onions available as sets are generally of a mild flavour, Jeanniellie. You need to look at onion seeds for this variety.

You need one of the 'yellow onions' (also called brown onions) for a more pungent flavour, which makes you cry when you chop it!! The yellow onions also store better and are less likely to bolt. Varieties are numerous, but a google on 'yellow onions' may help with ordering which type you prefer. I have found prices vary between £2-4 for a pack. Sets of 'sturon' and 'centurion' are available, or should be!, until the end of January. Check out fothergills, thomson & morgan, etc - all the usual top of the range seed and set providers. For a late plant of sets, fothergills have in the past come up trumps for me.

Sturon and Centurian etc would be classed as mild onions, Avkg. These are what we grow as they work well in our climate. But tey are not the 'strong' onions that Jeanniellie is asking about.

Intriguing bulbaholic as I have found the yellow/brown skins to be more pungent than anything other than the spanish purple which are not available as sets at this time here!! The sturon giant always make me weep with pleasure!!

I hope you're right about the yellow Sturon onions being strong, avksomething47, I set about 50 a couple of months ago and every one is growing well.
I'm keeping them covered for the Winter by a high polytunnel I've made, but wonder if this is necessary ?

Hello Hank - there are some mild yellow onions out there too - you need to choose carefully. In general though the purple tend to be sweeter than the yellow. I understand that the theory behind planting onions and garlic in the autumn/winter is that the colder temperatures cause a chemical reaction in the plant that makes them grow larger and put on more cloves. Your polytunnel will keep temperatures, especially in the day, higher. You could use the polytunnel - if it is transferable - for winter lettuces, rocket, salad onions, pak choi, starting some carrots, and land cress, for harvesting in spring, rather than waiting for summer. Rocket especially doesn't bolt when planted early or late - I never try to grow it in summer anymore.