Avery Hill Park, Eltham, Kent.

‘Colonel’ John Thomas North was desperate to leave his humble beginnings behind. He was even keener to leave behind the story of how he made his fortune – selling South American bird droppings as fertiliser. Victorian head gardeners across the country may have been grateful to the Nitrate King but none of their employers wanted anything to do with a man who had had his hands in seagull muck.

When he bought Avery Hill House North immediately set about improving both it and his reputation, hoping for a visit from the Prince of Wales, later Edward VII. That would show the chattering classes…

There’s not much left of the house – by all accounts even the Victorians thought it rather vulgar and certainly after his death no one wanted it. It fell into the hands of the local authority, various educational establishments and, more recently, the University of Greenwich and only the facade remains. Even that’s surrounded by unimaginative modern buildings. It’s a shame, since the Turkish baths alone  would have been worth seeing.

Part of North’s social mountaineering onslaught saw, in 1880, the building of a magnificent palm house, second only in size to the one at Kew Botanic Gardens.

North filled his grand conservatory with exotic plants from all over the world, with a fabulously erotic marble statue of the nymph Galetea reclining on a dolphin by the Italian sculptor Leopoldo Ansiglioni.

The Avery Hill Winter Garden is pretty much all that’s left, after years of being picked at by the University of Greenwich, who currently own it and even that is permanently on the watch-this-very-carefully list.

After the university announced plans to sell the campus for development locals amassed a ‘Save Our Winter Garden’ campaign. The council has pledged to enforce covenants on this extraordinary Victorian glasshouse and English Heritage are ‘interested’, but I’d suggest visiting this most secretive of secret gardens sooner rather than later.

Not all of it’s open and it’s in varying states of repair. The grand central area is reasonably well planted and maintained with a splendid Norfolk Pine as its centrepiece, and sundry giant palms and cacti filling four beds. Smaller, slightly less exotic specimens (though probably enticing to the Victorian eye) fill the beds lining the walls.

To the left of the main room another, of similarly large size, is pretty much closed off to the public. It’s hard to tell whether this is for structural reasons or just because it doesn’t have that much in the way of plants. When I visited a few years ago it was open but filled with bizzy-lizzies and Christmas cactus; now there isn’t even that.

Generally, though, despite the odd ferny intruder, the buildings seem to be in halfway decent nick.

It’s clear the Winter Gardens’ meagre funds have been directed to the conservatory to the right of the main hall. Here, lush planting surrounds Galatea’s pool – palms, ferns and a lot of arum lilies. A simple planting, but effective and carrying a real feel of sumptuousness.

Avery Hill Winter Garden is open, free of charge, Monday to Sunday 10.00am to 12.00pm and 1.00pm to 4.00pm (closed Christmas Day, Boxing Day, and New Year’s Day).

Enjoy the iron-work columns, many tree palms, naughty Galatea and Norfolk pine while you can. Edward VII never did.