Cranberries prefer damp, boggy acidic soil, so if you’re prepared to give a windowbox over to them, it’s best to line your windowbox with a plastic liner (eg. Pond liner) punched through with only two or three small holes. You will need to use a peat-based compost or a soil mix manipulated to be make it more acidic*. Water copiously in summer, preferably with rainwater.
Plant: Pot-grown plants at any time of year.
Varieties: CN, Early Black, McFarlin