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...

Now that summer's over, you can concentrate on the many culinary delights of autumn. And if you weren't already on the case in mid-September, then it's time to get out the woolly socks and garters...

Variety is everything with squashes and pumpkins: some (the Atlantic Giant pumpkin, for example) are bland and uninteresting, whereas others are sweet, creamy and delicious. Recommended varieties include Hundredweight (the traditional lantern pumpkin), Sweet Mama (a lovely small squash), Baby Bear, and most varieties of acorn squash. They are easy to grow if started under glass or on a windowsill. Don't plant them out until the risk of frost has passed. They need plenty of space, and love manure so much that some people actually plant them on top of old compost heaps. I just dig plenty in when I transplant them.

Interest in traditional apple varieties is on the increase, and has been one of the causes championed with considerable success by the farmers' markets movement. Some of the supermarkets have earned themselves a rare plus point by getting in on the act, too.

I always make a point of tasting any apple variety I have never encountered before. At the Bridport farmers' market I discovered for the first time the delights of the Lord Lambourne - a lovely crisp apple with a tart lemon tang and a hint of rosewater. People who really like apples tend to be quite fussy about the apples they like. Galas and Golden Delicious, sweet but bland, do nothing for me, whereas the first, hard, sharp, home-grown Cox's Orange Pippins, with their unmistakable honeyed citrus flavour note, are unbeatable. The later Cox's are often too sweet and mealy, and the recent mass imports from New Zealand, which keep us in Cox's through our early summer months and have a yellow skin and suspiciously even tiger streaking of red, don't seem like real Cox's at all.

The distinction between cookers and eaters can be a misleading one. From the cook's point of view, the more useful distinction is between apples that keep their shape when cooked, and those that dissolve into a purée. The best known of the latter is the good old Bramley, which is ideal for crumbles and pies. But if you want to make a classic French-style apple tart, with layers of thinly sliced apples overlapping in concentric circles, early-season Cox's, Reinettes or even Russets are the best bet.

Most varieties of apple travel and store extremely well. In some cases, notably Fiesta, Jonagold and Granny Smith, the flavour is actually improved by storage. However, even the best storing apples, once exposed to warm air in the greengrocer's or the house, will gradually begin to deteriorate. If the skin moves to form a wrinkle when pushed sideways with your thumb, it is starting to lose its crispness and, for me at least, is devoid of interest. The pigs, however, love them.

The walnut tree was introduced from Asia about 500 years ago. It does not spread very successfully when left to its own devices but they are not uncommon in woods and parkland, and indeed in people's gardens. The nuts do not always ripen fully in our climate, and it is best to allow them the benefit of any autumn sunshine and pick them as late as possible: late October or even early November. Ideally the fruit surrounding the nut should be split and the shell of the nut showing through. Peel away this fleshy case and, if you are not ready to use the walnuts straight away, or want to keep them for your nut bowl, leave them to dry in an airing cupboard for 24 hours, then transfer them to a cool, dry place. This should ensure they don't go mouldy. Wild walnuts can be used instead of the imported cultivated kind in any recipe, but because they have a particularly strong flavour I prefer to use them in savoury ones. They make a great pesto, in place of pine nuts.

The eating qualities of hare have long been celebrated, and there is still a regular market to supply those in the know. Good butchers may keep them in stock, but to be sure of getting one you should order it a few days in advance.

The price of a hare may vary considerably according to local availability but they are rarely expensive, and a large one will feed six greedy people. You may get a better price from a game dealer, and better still from a gamekeeper (you should get them for a knockdown price from a keeper just after a hare shoot).

The hunting of hares by almost any method is becoming controversial. Some conservationists maintain that hares are in great decline and should be protected. Many farmers, on the other hand, claim to be overrun with them. The truth is that both parties probably have a point: the distribution of hares in this country is very uneven. Hares are not strictly classed as game, and do not benefit from a close season as such. But they do enjoy partial protection, in that it is not permitted to 'offer a hare for sale' from the end of March to the beginning of August. This is when they are rearing their young and, given the concern that has been expressed about numbers in some areas, I think it is appropriate that they should be considered off-limits during these months.