Possible Clues:

• Area in shade will be soil
• Blight? It isn’t heard of in parts of the country
• It isn’t commonly a stain or blemish
• Corrupt, as evidence
• Contaminate home, leaving rubbish round
• Corrupt leaders in thrash arranged inside Number Ten
• Base of allotment isn't soil
• Damage, as a reputation
• Informally, it is not corrupt?
• As some might say, it's not muddy