Roscommon,
Ireland 
We moved to County Roscommon in Ireland just over two years ago, Before that we lived in Staffordshire where, on our clay soil, we grew onions on our allotment that were the envy of everyone. here we grow on peat. I have tried for the last two years to grow garlic with little success, and onions and leeks with even less. This soil is good for carrots, beans and spuds, and cabbages almost swoon with delight as they go in. Does anyone know if peaty soil is deficient in anything that onions need? No chemicals.
Thanks
Lorraine
31 Jan, 2016
Answers
I agree, your soil is probably too wet for onions. I would recommend constructing a raised garden bed. You can build a simple frame from 2 x 4s (untreated lumber of course). Fill with optimal growing medium and away you go. It will be good to use for years to come. I grow onions, carrots, beats, potatoes, parsnips & Brussels sprouts all side by side. They all do very well.
31 Jan, 2016
Yup agree with Bathgate a peaty soil is not what onions and garlic need, create a low raised bed and you'll be laughing...
31 Jan, 2016
My son lives up in the hills behind Bantry, West Cork, and finds he can't grow much at all. Even potatoes are difficult as they seem to get the blight. He's tried runner beans, carrots and most other veg but keeps persevering, sometimes even having enough of a crop for a meal or two. It's generally disappointing though.
It's the wet weather and the soil.
1 Feb, 2016
Your soil might be too wet for onions and might need an amendment to improve drainage as well as loosen it up a bit to encourage larger bulb growth. I do recommend that you purchase a soil test kit to analyze the soil specific to your garden so you may know what your soil needs to grow the vegetables you would like to have in your patch.
31 Jan, 2016