As soon as your seed potatoes arrive, unpack them and if you've time, start chitting by placing them in a single layer in a light, cool, frost-free spot. Begin this around six weeks before planting. While not essential, chitting will help get your potatoes off to a good start, and subsequently they'll produce an earlier harvest. There’s also no need to chit autumn or Christmas potatoes, as these are planted in summer.
First early and second early seed potatoes can be planted outdoors under fleece protection, while maincrops should wait until the risk of frost has eased, usually from mid-April. Autumn and Christmas potatoes are planted straight into trenches or potato bags from late July.
Dig a trench 8-13cm (3-5in) deep and add a balanced fertiliser before planting the tubers 30cm (12in) apart with the shoots facing upwards (if present), then cover lightly with soil. If using potato bags, plant into general-purpose compost with at least 20cm (8in) beneath the tubers.
When shoots reach about 20cm (8in) tall, earth up soil or compost around the stems to cover the lower two-thirds of the plant. Keep plants well watered as this boosts yield and helps prevent scab.
Planting and harvest times depend on the type:
First earlies: Plant mid-March to April and lift 10-12 weeks later (June to early July).
Second earlies: Plant early to mid-April and lift after 13-14 weeks (mid-July to August).
Maincrop: Plant from mid-April and harvest after 15-20 weeks (late August to October).
Autumn/Christmas: Plant from late July and lift from 12 weeks, protecting plants from frost.