what ph do potatoes like
1 Grow your potatoes in soil with a pH between 5.0 and 6.0. 2  Potatoes grown in soils with a higher pH seem prone to a disease called 'scab', which produces rough spots on the potato. 3  Adding compost or peat will help. 4  Don't plant your potatoes where tomatoes or eggplant were grown the year before.