David Clark Staff asked 14 years ago
I have potatoes in tubs all in fresh multipurpose compost with added Osmocote, religiously watered. In the last 2 weeks some leaves have yellowed between the veins and turned brown. There is no sign of any mould. Dr Hessayon’s book (The Vegetable Expert) suggests it could be magnesium deficiency. If you think this is likely, I would be very grateful if you would recommend a product to boost Mg levels.