A tree mural in north London that appeared on a residential building is the work of Banksy, the anonymous street artist has confirmed.

The artist claimed the mural as his own in an Instagram post on Monday, following a morning of speculation after it appeared on a building on Hornsey Road in Finsbury Park overnight.

The work, which is painted on a wall that sits behind the tree as the viewer looks south-east down Hornsey Road in the Finsbury Park area.

It features a lifesize depiction of a woman holding a pressure washer, having apparently sprayed green paint up the side of a block of flats. Viewed with the tree in the foreground and centred on the wall, the green paint mimics the foliage of the plant, which has been cut back in a process known as pollarding

One expert said on Monday morning he believes the work bears “all the hallmarks”.

“It has the right techniques. It’s got an interesting and an easy-to-understand message, a very clever location. And it really resonates the second you see it. And, with Banksy, context is everything,” James Peak told BBC Radio 4’s Today programme.

Crowds of people turned out to see the artwork on Monday morning. Wanja Sellers, a Hornsey Road resident who lives a few doors down from the mural, told PA news agency: “We’re so proud and delighted that Banksy chose our road and chose Finsbury Park for his work.

“The bright green colours represent Islington, which is lovely and also, of course, St Patrick’s Day, which is nice and festive.

“Choosing the colours of our borough just makes it feel like a personal message to us residents. We just feel so proud.”

Lidia Guerra, another Hornsey Road resident, said: “The way it’s been done with the paint spraying down reminds me of a weeping willow, so there’s perhaps a message about the struggle of nature with the dead tree in front.

“It’s just great – when we read about it last night, we knew we to come and see it as soon as possible. We feel so proud to think he chose our street.”

Peak created the BBC Radio 4 series The Banksy Story. He went to see the work on Sunday after receiving a tip-off.

“The message is clear: Nature’s struggling and it is up to us to help it grow back,” he told the BBC.

He described the scene as a “very busy, urban, built-up environment”, with the tree sitting in the gardens of some social housing. The figure of the woman, he said, was a “classic Banksy-style stencil”. And he noted that the shade of green used to represent the foliage was “exactly the same sort of virulent shade of green that Islington use for its social housing signs”.

He said: “So, when you step back, it looks like the tree has burst into life, but in a noticeably fake and synthetic way. And it’s pretty subtle for a massive tree, I’d say.” And the broadcaster added: “It’s spring now, and this tree should be bursting forth with leaves, but Banksy must have cycled past and thought how miserable it looks,” he said.

Peak said “To my mind it looks like a dead cert. But, as ever with Banksy, you never quite know, until he fesses up by posting it on his website.”

Before this piece, his last confirmed work was in December, when he painted military drones on to a stop sign in Peckham, south London.

That work removed less than an hour after it was confirmed to be genuine on the artist’s social media, with witnesses reporting it was taken down by a man with bolt cutters.

Two men were later arrested on suspicion of theft and criminal damage.