When the leaves are still turning from green to yellow (which is usually the case at the beginning of October), then as long as the weather is fine you can continue to persuade yourself that it is summer. But when the leaves are unambiguously brown, and there are almost as many of them on the ground as on the trees (which is always the case by the end of October), then it's time to face facts: summer's over. That's okay, though - because now you can concentrate on the many culinary delights of autumn.

If you weren't already on the case in mid-September, then it's time to get out the woolly socks and garters, along with the cleft walking stick and leather hat. (You don't have to dress like an idiot when mushroom hunting but a lot of people seem to think it helps.)

You certainly don't need to live in the country to forage fungi. Urban enthusiasts should be on the alert, too. Many of our parks and play areas have grass and wooded areas that are unsprayed and ungrazed and therefore prime habitat for wild-mushroom hunting. Hyde Park in central London has been known to yield some monster puffballs. Hampstead Heath and Epping Forest are also teeming with edible varieties. No doubt urban parks across the UK can yield similar finds. Even the rural mycophile should be ‘urban aware'. Here in Dorset I have found a good crop of parasol mushrooms growing on a roundabout on the outskirts of Bridport.

Don't forget to look up as well as down. Some of the tastiest fungi grow on trees, including pleurottes and the unmissably sulphur-coloured chicken of the woods. But my favourite is beefsteak fungus, also known as ox-tongue (you'll see just how appropriate both these names are when you find one). This reddish-brown bracket fungus grows on chestnut and oak trees, especially big old ones, and is usually found at head height or below. It is relatively common, and a great treat if you happen to find it. Trim it, discarding any coarse, woody edges, and slice thinly, like liver. You can cook it like liver too, frying the slices gently in butter, with garlic and chopped fresh sage. Add a splash of white wine and a little cream at the end, letting them bubble down with the juices from the mushrooms to make a delicious sauce.

Don't take any chances when collecting fungi. A comprehensive field guide, such as Roger Phillips' Mushrooms and Other Fungi of Great Britain and Europe (Pan Books, 1981), is invaluable or *John Wright's River Cottage Handbook No 1 - Mushrooms or River Cottage Mushroom Magic DVD.  You should never risk eating a mushroom unless you are completely confident of its identification.  There are some virulently poisonous fungi out there, so there's not mushroom for error (sorry).

*John is also the host of our Walk on the wild side - mushroom foraging courses and the photographer of our beautiful wild mushroom prints.

Incidentally, we may be in the October section but it's worth noting that the season for gathering mushrooms is far longer than many amateur enthusiasts generally give credit for. Many varieties - notably chanterelles and field mushrooms - are a summer phenomenon as much as an autumn one. And when autumn is preferred (as with hedgehog fungus and wood blewits, for example), the very mild weather of recent years has meant good hauls can be had as late as early December. Your forest foraging may also lead you to some other October treats: sloes, crab apples and the first of the sweet chestnuts. British chestnuts gathered from the wild may be smaller than those imported from the Continent but they have at least as good a flavour. If you find a windfall, it's worth filling your boots, as they keep well too. Let them dry in a warm room for a day or so, then store them in a cool, dry place and they'll keep until Christmas.

One often-unsung hero of the October garden is the late-fruiting raspberry. The aptly named Autumn Bliss is a particularly fine variety, for which I would urge anyone who grows soft fruit to make space. I often find myself doubting whether it will really produce the promised October crop. Then, just when I've almost forgotten them, those bedraggled canes, with yellowing leaves and drooping stems, suddenly remember their autumn duty and throw up cluster after cluster of luscious, crimson berries. They're so good I've even invented a new dish to celebrate them, and given it their name.  Click here for the recipe.

And, of course, it would be criminal not to make the most of our native apples and pears. I have chosen six varieties of apple for my little orchard, with two trees of each variety. I can tell you, I agonised over the catalogue (from Scott's of Merriot, which is luckily just a few miles away in Somerset). My aim was to get a range of delicious, characterful apples, favouring those that are crisp and tart over ones that may be sweeter and softer (that's my personal taste). I also wanted a crop that spreads through the season, in both directions, from its prime in October. I had the catalogue in bed for weeks. But in the end I think I did pretty well, Here's what I plumped for, in cropping order:

Discovery: the first to ripen, these can usually be picked by mid-August. Crisp and juicy, tart and refreshing, though relatively ‘one-note' in flavour. Discovery are useless keepers and are best eaten straight from the tree. They are all over by the beginning of October.

Grenadier: a very useful early cropper, this is technically a cooker. However, thin slices of the tart, crisp flesh have a fresh, summery taste and go very well in a salad or with cheese. They also make a delicious, tart juice that can be sweetened with a little icing sugar and frozen as a granita or sorbet.

Bramley's seedling: the ultimate cooker, Bramleys cook naturally and quickly to a tart, refreshing pulp, which is the basis of all the best apple pies and crumbles, as well as my Bramley burnt creams. Usually ready to pick by the end of October, they are really a November apple. If you wrap them individually in newspaper and store in a cool place, they will keep right through the winter until March.

Egremont Russet: though a few people seem mildly phobic about its rough, russeted skin, this apple is widely loved, and rightly so. It has to be the ultimate 'nutty' apple. Crisp and sweet, it is very hard to beat for flavour. Personally I prefer it towards the beginning of the season (October), when it has more crispness and acidity, but others go the opposite way, admiring the fully rounded flavour of apples that have been in store for a while. As this implies, it is a reasonable keeper - but not much cop after Christmas.

Ashmead's Kernel: an outstanding late apple, which is not usually ready until mid-November. It has a brilliant crisp texture and delightful, almost sherbety taste, with an excellent balance of fruit flavours, sweetness and acidity. Sadly they are not very productive. My two-year-old tree produced only two fruits last year! Should come good in a few years, though.

Orleans Reinette: Another late apple, this is fortunately hardier and more prolific than Ashmead's Kernel, which, with its slight russeting and pinky-orange bloom, it closely resembles. But it doesn't keep as well. Apart from that, I can't recommend this underrated apple highly enough. It has a wonderfully complex flavour, which combines the Russet's mellowness and nuttiness with Ashmead's lively sparkle, and even some tropical, lychee-like overtones.

Of course, this is a highly personal selection. There are dozens of other English varieties that I could have gone for, and would probably now love just as much. As a matter of principle, I taste and buy every new English apple I encounter during the season. With this kind of exploratory tasting in mind, October is a great month for visiting farmer's markets. You may well discover a new personal favourite, and perhaps even feel moved to grow it.

Incidentally, we are generally very bad at keeping our apples at home. Almost any apple left in the fruit bowl in a warm kitchen will go into rapid decline, getting wrinkly on the outside and soft and mealy inside. Apples should be kept in a cool larder or even the fridge, and they will remain the outstanding seasonal treats that they ought to be.