Off-track bletting: Forget apple and pear trees - grow a taste of the unexpected

Pick of the crop: Mark Diacono examines Otter Farm's quinces (Jason Ingram)

Bletting. It's not your average sort of conversational word. But talk to Mark Diacono, the owner and sole proprietor of Otter Farm in Devon, and it works its way in pretty quick. Because "bletting" is what everyday folk do to their medlars – a hard, tart fruit if eaten raw – to make them edible. Effectively, it means leaving them lying around for a week or two to rot ever so slightly. Sounds disgusting, tastes delicious. And Diacono is on a one-man quest at this time of year: to get more of us bletting.

"And just now it's bare-root time, the perfect time to plant fruit," he insists. "There's a little bit of warmth in the soil, so you can get a little bit of root growth before the real cold sets in." Apart from medlars, what kind? "All sorts," he laughs – and he should know. For six years now he's been running his "climate-change farm" near the market town of Honiton, which incorporates not just a fruit-tree nursery, but also exotic crops that benefit from warmer summers.

Otter Farm bare-root trees are a select bunch, from a distinguished selection made by Diacono himself. As author of the River Cottage Handbook on the subject of fruit, he has plenty of useful opinions on the subject. But he also has some strict views, too. If you were pondering treating a delightful relative to a partridge in a pear tree this Christmas, you'll find him urging you to think again.

"Look, apples and pears are fantastic trees," he says, "but if you have room for only one or two, don't buy them. You can get good apples and pears in the shops." Instead, the author of 2011's award-winning cookbook A Taste of the Unexpected is, not surprisingly, urging us to veer off the standard path and walk on the wild side.

Which is where the bletting comes in. Big time. "Medlars, quinces, mulberries," he pronounces, "you can't buy them for love nor money." And these old-fashioned fruits are fantastically juicy, beautifully fragrant and totally unusual. So why don't we hear more about them? "They don't fit into the supermarket system." But plant one yourself, Diacono urges, and you too could be home-bletting.

If that idea sounds just a bit much, consider the halfway house of the peach family. "Apricots, nectarines and peaches are unbelievably good when you grow them yourself. Plus, they have the most beautiful pink blossom. And on a genuine dwarf tree you get 30 or 40 peaches, no trouble, once they're established. On a tiny little tree!"

So if you're wondering how to say goodbye to 2012 and see in the new gardening year, think on a new fruit tree to see you through the winter.

Diacono will be spending his winter out walking his fields, but what does he do on those dark days when there's no going outside? It turns out the answer is Scrabble. "Last year, I won a game by putting down all my letters, so I got 50 extra points, on the triple-word score. And it was the last word of the game!" And the word he played? "Bletting!"

Diacono's delights

Peach – Paraguayo

"Just delicious," says Mark. "It's like a doughnut – slightly flattened, white flesh, really juicy gorgeous dark-pink flowers. And it'll only ever grow 1½m tall." £44 for four-year-old tree

Quince – Lezcovacz

"Siberian and marvellous. The flowers are like little barbershop twists and the smell is a cloud of loveliness. The fruit is gorgeous just baked with cream, brown sugar, butter, some Christmas spices and raisins spiced with brandy." £29.50 for a dwarf tree

Medlar – Nottingham

"They look beautiful, with gorgeous dog-rose flowers, which will flower erratically all the way through the year, and the leaves do classic autumn traffic-light business." And that's before you get to the bletting. £30 for two-year-old tree.

All available from shop.otterfarm.co.uk