I'm new to allotment gardening. last October I planted some white (Radar) and (Red Baron) onion sets. They have grown fairly well in places, but some bolted and others seem to have grown the stems from the root area, and not from the top of the onion. The latter makes the onion misshapen by leaving a "V" notch in the side. My soil is quite sandy and has been watered well, but somewhat irregularly during the Spring and Summer. Other onions I grew from seed and planted out March/April are all OK.
Does anyone know what's caused the strange stem growth.
