Police warned people to keep sheds locked, install lighting and alarms and mark valuable property after a recent spate of thefts.
Richmond police said in the past two weeks there had been an increase in burglaries, particularly theft of bikes from garden sheds.
Officers said the areas worst-affected were St Margarets, Whitton Road, Hampton, Teddington and south Richmond and the burglaries were carried out in one of two ways.
Either burglars cut though padlocks on sheds or unscrew the hinge screws and remove the doors before stealing bikes and either ride them away or drive them away in vans.
People are advised to lock their sheds, install lighting and alarms, mark their property, use clutch screws rather than normal ones and padlock bikes inside sheds to other heavy items like lawnmowers.
Neighbourhood Inspector Hannah Wheeler said: “Crimes like these are fairly quick to carry out and the majority are accessed by dark rear alleyways, cycles are easy to sell on as are garden tools.
“You can help by making it difficult to gain access to your rear gardens using lighting, shed alarms and secure fencing.
“I can assure you we are doing all we can to apprehend those responsible and also prevent any further crimes.”
To report suspicious behaviour call 999 and if you have any information about these crimes call 101 or Crimestoppers anonymously on 0800 555 111.