lack of iron in soil?
United Kingdom 
Several plants in my pots and hanging baskets eg petunias are going white in their leaves and then dying. The veins remain green, but all the rest of the leaf goes white. Is this a lack of iron, and, if so, what can I add to the soil?
26 Jun, 2009
Answers
The most common cause of this in bedding plants is sudden cold, but I can't think, unless you live somewhere chilly, that's the cause. What compost did you use, and what are you feeding with? (I am assuming you're not talking about powdery mildew coating the leaves and making them white, but that the leaf itself is white)
26 Jun, 2009
It could be a high level of salts. Try mixing in a good mix of sphagnum moss throughout where poss.
26 Jun, 2009