Onion (Heat Treated) Red Baron AGM Sets

Heat treated onion sets for sale, such as Red Baron onion sets, offer strong performance and excellent flavour, making them a top choice for growing onions successfully. A heat treated onion set consists of small onion bulbs that have been "turbo-charged" by storing them in warm, sterile conditions for several weeks or months. This heat treatment specifically kills the embryonic flower inside the set, effectively preventing premature bolting and early flowering, which can ruin the bulb’s growth. As a result, heat treated onion sets establish and grow quicker, produce higher yields, and develop larger, healthier onions.

Red Baron onion sets should be planted from early March through mid-April, when the soil has warmed and is not waterlogged. If planting under cloches or in a cold frame, sets can go in about two weeks earlier, in late February to early March.

Red Baron onion sets thrive in well-drained, fertile soil, spaced about 10cm apart in rows 25-30cm apart. Red Baron onions are typically ready to harvest from late July through September in the UK. The best time to harvest is when the leaves start to yellow and fall over, signalling that the onions have reached full size and maturity. Once the tops have died back, gently pull the onions from the soil and leave them to cure in a warm, dry, and well-ventilated place for a couple of weeks.