Recycling is so popular in Birmingham that exhausted council bin men have to collect up to 250 tonnes of garden waste a week on top of their normal duties.
The pressure on crews has led to fresh calls for refuse sacks to be replaced by wheelie bins, which are automatically lifted by machines when being emptied.
Officials have been taken by surprise at the success of a fortnightly green waste collection pilot project, which is being rolled out to 100,000 households across suburban parts of Birmingham.
More than twice as much waste for composting is being put out for collection than the council anticipated.
In one eight-week period 2,000 tonnes of garden material was collected from 80,000 homes.
The strain on crews led a senior city councillor to suggest that the sacks might be replaced by wheelie bins.
Martin Mullaney, chairman of the transportation scrutiny committee, said: "Sacks of garden waste are being collected somewhere in the city every day of the week. The crews also have to pick up household waste as part of their normal duties.
"You can put out as much as you like and some people with big gardens are putting out up to 20 sacks of green waste, which then have to be picked up and thrown into a lorry.
"We have got to be open minded about wheelie bins. They wouldn't be suitable in some parts of the city, where paths are hilly, but they would be suitable in areas like Moseley."
Coun Mullaney's remarks are likely to re-ignite a bitter row over wheelie bins. The council's ruling Conservative-Liberal Democrat coalition said last year it would not pay an estimated £2.2 million to equip Birmingham households with wheeled bins.
The stance contrasts with Solihull, where the borough council yesterday unveiled its new wheelie bin-based green waste collection service.
The scheme, which is being phased in over three years, follows a successful pilot project.
Coun Mullaney (Lib Dem Moseley & King's Heath) said he hoped a number of teething problems affecting the green waste collections in Birmingham could be resolved.
He added: "It is taking longer than expected to collect the compost, partly because of an unexpectedly huge amount being left out but also because residents keep tying the sacks which means the refuse collectors have to cut open the sacks to empty them into the truck.
"People are also getting confused as to which week is compost collecting week." ..SUPL: