Five fire engines and around 35 firefighters were called to a fire on Lavidge Road in Eltham.
A number of garden sheds and a fence were destroyed by the blaze. One woman was treated at the scene for smoke inhalation and taken to hospital by London Ambulance Service crews.
Firefighters cooled and removed four LPG cylinders as some cylinders can explode when exposed to heat.
The fire is believed to have been caused by a bonfire.
Leading Firefighter Kieran Lovell, who was at the scene, said: "The fire was across three gardens and was very visible and crews worked hard to stop it spreading further.
"The blaze also involved garden equipment and some pallets and wood which fuelled the fire and prompted a high number of calls to our Control Room.
"We would urge people to consider if their bonfire is necessary and to take care if you’re burning waste at home.
“Always check your local authority’s advice on bonfires and follow our safety tips.
"Never use paraffin or petrol on your bonfire and make sure you build it far away from any buildings, sheds and fences and never leave it unattended.”
The Brigade's 999 Control Officers took 45 calls to the blaze.
The Brigade was called at 0235 and the fire was under control by 0416. Fire crews from Eltham, Sidcup, Lee Green, Bromley and Lewisham fire stations were at the scene.
Bonfire safety tips