Four fire engines and around 25 firefighters tackled a fire on The Avenue in West Wickham.
Three garden sheds and some fence panels were destroyed by the fire. There were no reports of any injuries.
The fire is believed to have been accidental and was caused by a bonfire spreading out of control.
A London Fire Brigade spokesperson said: "We would urge people to consider if their bonfire is necessary and to take care if you’re burning waste at home or at work.
"If you’re having a bonfire never leave it unattended and consider your neighbours if you do decide to have a fire in your garden.
"Make sure you build it clear of buildings, garden sheds, fences and hedges and never use flammable liquids to start it or burn dangerous items such as aerosol cans. Always keep a bucket of water or a hosepipe nearby in case of fire.
“Always check your local authority’s advice on bonfires and follow our safety tips."
Control Officers took the first of 29 calls at 1837 and mobilised crews from Bromley, Beckenham and Woodside fire stations to the scene. The fire was extinguished by 1923.