Norland

Late blight is one of the most damaging diseases for potatoes, often showing up as dark, water-soaked leaf spots with rapid spread in cool, humid weather. Remove and destroy infected leaves immediately, avoid overhead watering, and improve airflow by keeping plants hilled and not overcrowded. If it’s already in your area or you see early spots, use a labeled protective fungicide and repeat on the schedule on the label, because potato foliage can collapse quickly.

Start checking for harvest readiness at about 65 days after planting, but use plant cues too: when the foliage starts yellowing and dying back, tubers are nearing maturity. For “new potatoes,” harvest earlier when plants have flowered and tubers are small with thin skins that rub off easily. For mature storage, wait until the vines fully die back and the skins have set (they resist rubbing off), then harvest promptly to avoid skin damage.