The Great British Bake-Off (BBC1, 8pm)

ACCORDING to Radio Times, for the first (and possibly last) time ever it’s Botanical Week, following the rough guideline of anything that grows, goes. Nearly all opt for floral shirts and jackets in the tent of dreams, though one of the stars departing for Channel 4 next year, Paul Hollywood, is dressed top to toe in black.

Like a lot of series of this ilk, I enjoyed the first ingredients of both amateur and celebrity Bake-Offs, but found my tastebuds rather tainted by the constant confection of cooks and cakes. A whole two pages of Radio Times is devoted to readers views such as Sue Vivian-Wright who got her wish that Mary Berry wouldn't be "decamping" to Channel 4, following the example of hosts Mel Giedroyc and Sue Perkins. Just Hollywood is defecting it appears. Another reader calls for senior Beeb management to have a whip-round and buy Bake Off back; a rival series called Never Enough Dough or Battered But Not Bruised is suggested and Facebook has gone into meltdown over Channel 4's insistence of "after the break this happens" segments in most of its programming.

Columnist Alison Graham has also been critical of Channel 4's tendency to create a peak in the action every ten minutes and staging little cliffhangers to ensure that viewers return about the break. "Bake Off will no longer be a delightfully delicate meander, it will be a motorway journey with too many loo-breaks (and oh dear, we'll have to have flipping recaps every time we return to the tent)," she says.

Bravely, Jay Hunt, the C4 boss who bought Bake Off, replies: "Over the past seven years, Love Productions and the BBC have grown Bake Off from a quaint idea into a global hit. It's sold to 23 countries and is loved by viewers, from Denmark to Australia. But last week talks to make more series for the BBC broke down irreparably. In a very competitive situation, Bake Off was in danger of being lost to free-to-air audiences behind a pay wall. By bringing the show to Channel 4, Love Productions ensured Bake Off will be a on a terrestrial channel for millions to enjoy.

"It'll be made by the same team who have made it from the very start. And we'll be asking them to change is as little as possible. Like you, I love it just as it is."

Tonight's show features the biggest challenge so far, three tiers of decorated cake, which must include botanically flavoured sponges and floral designs.

Grand Designs (Channel 4, 9pm)

KEVIN McCloud follows Matt and Sophie White from Sussex as they build a giant family house of fun for themselves and their children. Going against the norm of designing a serious and practical home, the couple's property features a revolving bookcase door, secret dens, hiding places, one-way mirrors, and a fireman's pole. Matt uses a steel frame system to allow them to change the layout of the property, and other changes include amending the window shapes and sizes, and adding a half floor to create a James Bond room.

DCI Banks (ITV, 9pm)

PART one of two. The team tries to find out who was responsible for the brutal stabbing of DS Annie Cabbot (Andrew Lowe), but their dogged police work is thwarted when No 1 suspect shady businessman Steve Richards (Shaun Dooley) has an alibi. Meanwhile, as Chief Superintendent Anderson (Shaun Dingwall) puts pressure on Helen (Caroline Catz) to close the case, Banks (Stockton's Stephen Tompkinson) becomes certain that Richards is the perpetrator, but when his obsession sends him over the edge, Anderson questions if he is up to the job.

Andrea Lowe and Caroline Catz.

Britain's Lost Masterpieces (BBC4, 9pm)

IN this new series, art experts Jacky Klein and Dr Bendor Grosvenor are on a tour of the nation's museums and country houses, ready to track down previously unknown paintings by some of the world's greatest artists. In the first edition, the pair head to a museum store in Swansea, where they reveal a multi-million pound lost masterpiece with the potential to rewrite art history.

Viv Hardwick