I tried an experiment this year sowing onions later on 8th April, transplanting clumps/singles on May 7th into compost which still has significant browns not fully digested.
The compost choice was after reading somewhere that ‘onions like it rough’. The late date was trying to avoid allium leaf miner spring breeding, with a harvest hopefully well before autumn breeding. I also tended to find onions not really enjoying NW London in early Aprils, even under fleece.
They seem to have accelerated away very well, nearly doubling in height since transplantation and have deep green colour signifying healthy young plants.
Is this just the perfect temperatures (14-19C max, 7-11C min) in the two weeks since transplantation meaning optimal growth conditions, or does rough compost really suit onions?
