Ratte

Late blight shows as dark, water-soaked spots on leaves that quickly spread, often followed by a grayish fungal growth on the underside. Remove and destroy infected foliage immediately, and avoid watering the leaves—water at the soil line and keep plants well hilled to protect tubers. If the problem is starting or recurring in your area, use a labeled late-blight fungicide early and repeat according to the label schedule (don’t wait for full collapse).

Start checking for “new potatoes” around 60 days, but for full-size Ratte tubers wait closer to the 85-day maturity. They’re ready when the plants begin to yellow and flop, and the tuber skins feel firm and won’t rub off easily when you gently dig one up. Harvest on a dry day, then cure the tubers at cool, humid conditions for about 1–2 weeks to toughen skins for storage.