It is important to wait until the crops are fully mature, with dead haulm and tubers that have hard skins, before lifting them. It is not recommended to lift crops with immature or blighted foliage. After burning off the foliage, it is advisable to allow at least 10 days for the skins to harden for most crops, and around 21 days for those with large, vigorous foliage. Certified crops for seed are burnt off by the certifying authority on a specific date to prevent aphid infestation and virus introduction. The burning also reduces the size of seed tubers. Harvesting during the relatively early period (mid-September to mid-October) results in drier conditions, cleaner and easier lifting, less dirt, better wound healing, and cooking quality. It is vital to handle the tools and machinery with care to avoid damage during harvesting and transportation.
Harvesting of potatoes is normally done by a mechanical lifter, or by hand on smaller scales. Harvested tubers should be moved to a cool, dry storage area as soon as possible. Exposing the tubers to light, induces the formation of the toxin solanine, turning them green. This affects the quality of the harvest.