Staffordshire,
United Kingdom 
Hi can u tell me why my sweet peas get white spots and gradually the leaves and stems go completely white brittle and the whole plant dies. I buy from different garden centres and have also brought dwarf types.
25 Apr, 2012
Answers
You could take them back to where you bought them for their verdict...and some replacements. They should be selling healthy plants.
25 Apr, 2012
Sounds like Mildew. That is usually caused or made worse by dryness at the roots. So give them a lot more water and spray with a fungicide or full cream milk/water mix (1part milk to 9 parts water) as the first sign of the leaf spotting.
25 Apr, 2012