The best time to harvest potatoes depends on the potato variety and the stage of plant growth:
- Baby or new potatoes can be harvested about 7-8 weeks (roughly 50-60 days) after planting when the tubers are about 1-2 inches in diameter. These have thin skins and are tender but not good for long storage. At this stage, the plants are still green and lush.
- Flowering potato plants indicate the potatoes are ready to harvest soon. After the flowers drop, new potatoes can be dug up. However, not all varieties flower, so this sign may not always apply.
- By the plant's maturity date, usually between 55-120 days based on variety, potatoes are ready for full harvest. Potatoes fall into early (55-70 days), mid-season (70-90 days), and late-season (90-120 days) categories with corresponding days to maturity.
- The best sign for harvesting maincrop/storing potatoes is when the potato plant foliage has completely died back and turned brown. It's often advised to wait a few days after this for skins to toughen for better storage.
- If the first frost is approaching, potatoes should be harvested before tubers freeze and turn to mush. In mild climates, potatoes can sometimes remain in soil longer and still be fine.
- For different types:
- Early potatoes: harvest June-July, when flowers bloom or buds drop, tubers size of hen's eggs
- Second earlies: July-August
- Maincrop: late August to October, harvesting after foliage yellows and dies back
In summary, potatoes can be harvested anytime from about 7-8 weeks after planting for new potatoes up until the vine die-back for maincrop potatoes, usually within 90-120 days. Waiting for foliage to die back ensures fully matured tubers with tougher skins suitable for storage.
