An early savoy cabbage with green inner heads, wrapped by deep purple leaves. A sweet, nutrient-packed vegetable, that has always been a ‘superfood’ and may well have invented the idea. Stores well. When to Plant Zone 1: August–May Zone 2: Any time Zone 3: Any time Zone 4: April–December For zone map click here Soil Prepare your garden bed with green manure at the end of the previous season. Cut down your summer beans and turn them through the soil a couple of weeks before planting.  Add well-rotted manure and compost to increase the amount of organic matter in the soil. Soil pH Level 6.5–7.5 Position Sunny, well-drained spot in the patch. Avoid planting brassicas in the same place each year.