The large exhibition Onion Bunton's Showstopper, that should have been sowed at Christmas should now be big enough to plant out into their final positions.
Before planting, give the soil a good dressing of Vitax Q4 fertiliser at 2oz per square yard. It's a good idea to plant your large onions 15in (38cm) apart along the row, and space rows 18in (45cm) apart in-between rows.
When planting Onions try to plant so all the leaves run down the row the same way, this will make hoeing in-between plants easier later in the season, and will hopefully eliminate the chance of breaking off any leaves.
Because every leaf you break is a skin you will lose and your onions won't be quite as big.