How to protect potato tubers from phytophthora during late summerYellowing foliage and wilting potato stems in August often lead gardeners to harvest prematurely. To determine if potatoes are ready for mass harvest, gardeners should observe the plants: look for noticeable wilting and yellowing of the lower leaves. Managing Late Blight (Phytophthora)The appearance of characteristic dark spots on leaves in late summer indicates phytophthora. The Curing Period and Storage PreparationTo ensure long-term storage, tubers must undergo a curing period rather than being moved directly into a damp cellar. Excess moisture in the cellar promotes fungal growth; therefore, it is safer to gently remove dry soil by hand using gloves.