Gangs of rogue gardeners offering tree and hedge cutting services are operating in parts of mid Wales, Dyfed-Powys Police have warned.
People living in Llandrindod Wells, Powys, are being urged to be cautious after complaints.
Trading standards officers and the police in the area are working together to tackle the problem.
The gangs are said to carry out poor work which is often used as a distraction to steal from households.
Councillor Graham Brown, the board member responsible for public protection, said: "Some residents are tempted by offers of cheap work from these people but our experience is that that work is extremely poor and they charge extortionate rates.
"Anyone thinking of having any work carried out should consider all aspects very carefully and particularly ensure that the prices quoted are fair and reasonable, including the total price payable on completion of work."
Ch Insp Andy Twigger said people should remain vigilant: "It's important that householders never allow anybody access to their homes or premises without first checking identification.
"In regards to Trading Standards issues, I would also like to remind members of the public that they have a cooling-off period with any contracts, which allows them to change their mind within that timeframe."