Potatoes have a long growing season and with a little crop management their continued production can be easily maintained. It is good practice to understand when to start growing potatoes. Potatoes can be divided into 3 categories, early, second early and maincrop varieties.
The categories are defined by the length of time they take to reach maturity and by preparing and planting according to these characteristics it is possible to have a steady supply of potatoes harvesting from June through to October. First earlies are ready for harvest after 100 days, second earlies can be lifted around 120 days weeks after planting while maincrop can stay in the ground for up to 160 days, producing a much heavier yield of larger potatoes.
The first and second early varieties, well suited to container planting, reach maturity before pest and blight can develop in the garden producing small clutches of new potatoes. They generally have thin skin and a delicate texture, traditionally steamed and eaten as a salad potato straight from the garden. The shorter growing period and extra protection provided with container or bag cultivation means the seed potato can be planted earlier in the season resulting in an early harvest and the opportunity for a successive sowing.
All varieties benefit from chitting before planting by setting the seed potato in a light, frost free room and allowing shoots to develop. Egg cartons are ideal for this. Chitting should be started about six week before planting and will normally result in bringing the harvesting date forward by 3-4 weeks. The potato is ready for planting when the shoot is 1in/25mm long.
Early potatoes can be planted mid-March with second earlies a few weeks later although planting times will vary throughout the country. More northerly areas should be delayed by up to two to three weeks depending on weather and risk of frost. Maincrop varieties are generally planted in April.
The potato year starts in January when seed is delivered and chitting starts, then remains on the gardening calendar through to the late Autumn harvest. In more temperate climates or by using a polytunnel it is possible to grow a second maincrop, planted in late summer, ready for the table at Christmas.