Having seen some of the replies to M&MBM regarding blight I am now a bit worried about my potato sacks. I have 8 bags dotted among my OH shrubs. I have made drainage holes and I do water them. Have other grapes had blight when growing in sacks. I wonder because obviously the moisture is probably retained better in a sack than in the ground and if wet weather can cause blight can a watering can do it too. Should I keep sticking my finger in to test the soil? How damp should it be, do they prefer it drier? Sanjo