If you're plant is going mouldy then it may have a bacterial or fungal infection, an example is shown below.

None of the infections are harmful to human health, but local farmers can get worried about problems spreading to their crops. The risks are very low but we need to ensure that it doesn't happen.
If you think your plant is infected please dispose of it either by putting it securely in a bin bag or by burying it. Thank you for your help and if you have any queries please ring us an we will be happy to advise, telephone 01865 782260.