Now on Extreme Gardens, Charlie Dimmock deadheads on a cliff . . .

And now on BBC1, hold on to your secateurs, because it’s time for some Celebrity Extreme Gardening . . . despite the craze for evermore convoluted combinations of popular telly genres, no one has yet thought to mix Bear Grylls’s survivalist ordeals with the Chelsea Flower Show.

But it’s only a matter of time. Who wouldn’t tune in to see Charlie dimmock abseil down Beachy Head to deadhead some begonias, or thrill as Alan Titchmarsh jumps out of a helicopter with a trowel between his teeth?

We had a taste of the format as a 65-year- old Cambodian gardener set off to do some weeding at the temple of Angkor Wat on Sacred Wonders (BBC1).

Though I might have misheard, the man’s name sounded like Loon: that’s appropriate, because the weeds were at the top of the crumbling stone pinnacles, 200ft high, and Loon was climbing barefoot with a bamboo pole for a ladder. And no safety ropes.

Unwanted greenery on English church roofs usually means a bit of moss, but, in the sweltering tropics, a small tree can spring up overnight. Loon had to start at dawn and work fast, before the baking sunshine made the stone towers too hot to touch. Think of

that next time you’re digging up a dandelion.

Sacred Wonders is one of those compendium shows that string together gorgeous footage of interesting places and a few fleeting interviews.

We watched the vast gold throne of the Virgen de la Esperanza being carried through the streets of Malaga, in Spain, and met a novice monk at China’s Shaolin Temple preparing for his kung fu exams.

At a Hindu temple in neasden, north London, a polite medical student named Miraj revealed how much trouble goes into the acres of food offerings for the gods — 10,000 biscuits and 30,000 sweetmeats, arranged in towers and pyramids.

Carrying the ornate displays, Miraj’s hands never trembled: the boy will make a good surgeon.

But the show lost its way in the final 15 minutes, as we followed paramedics from the international humanitarian Red Crescent Movement on duty at the Wailing Wall. Suddenly, we seemed to be watching out- takes from the Jerusalem edition of Ambulance.

It got worse, with a ‘making of’ segment at the end that involved a film crew stuck in a traffic jam.

Sacred Wonders works well when it’s slow and dreamy — not when it’s plain boring.

Fred Sirieix was getting dreamy about the world’s most pretentious dishes in the final part of his roving restaurateur show, Remarkable Places To Eat (BBC2). He visited Mugaritz in San Sebastian, northern Spain, to sample a £200 tasting menu that included crisps made from sheep’s milk, garnished with wild flower petals and ‘ presented on a piece of volcanic rock’.

Then there was a piece of chicken skin moulded into a pig’s face and a spoonful of steak tartare covered with mould — that is, ‘served under a blanket of penicillin’.

In all its globe-trotting and fact-finding over the past month, the chief lesson of this series has been that I never want to go to dinner with Fred. The man’s tastes are demented.

He went into ecstasies in a backstreet bar over a tortilla that was so runny he had to mop it up with bread: ‘Look at the egg yolk, completely almost raw inside!’

The real attraction of this dish seemed to be that the chef made just one per day, and diners had to beg and plead to be granted a slice. One man came all the way from Japan and was turned away. More fool him.