Walk through a wood at this time of the year and you’ll probably encounter that distinctive musty aroma of moist earth, rotting leaves and fungi. My favourite wood – both in spring and autumn – is Pinsley Wood, Church Hanborough, is an ancient remnant of Wychwood Forest which you can find by walking the green lane besides The Hand and Shears pub. My dog loves this wood too; it has such a magical feel. The assortment of fungi here is exciting but as I’ve never mastered the skill of identifying mushrooms with confidence we don’t walk the wood to pick them. Rather I admire their beauty and tenacious pushing through the earth and I spend ages photographing them and the leafy earth on which they grow. Fungi can be found on grassy areas too, particularly fields where cattle and sheep have grazed. The fascinating thing about fungi is that instead of feeding from the sun, they draw nutrients from dead or decaying vegetation and organic matter. Because of this it’s disputed as to whether they should be classified as a plant. But there’s no dispute about their health-giving properties and high protein content which makes a great addition to a vegetarian’s diet. Mushrooms contain useful B vitamins too, also potassium and vitamin D, essential for the absorption of calcium. Nutritionists advise eating a mixture of varieties to reap all the benefits.

Fortunately several varieties can be cultivated. Have fun with gourmet growing kits on the kitchen windowsill for pearl oyster mushrooms. You can also buy plugs of spawn to insert into freshly-cut logs for shiitake. There’s even a mushroom named Lion’s Main which grows on logs and produces attractive cascading white spines, which taste vaguely of lobster. You can grow popular chestnut mushrooms in your own home too. There was a time when there were loads of excellent farms in the UK, but growers in Poland began flooding the market with a cheaper product, making it hard for ours to compete.

Mushroom farmer Richard Lainchbury and his wife Wendy have beaten that trend, however. They sell at Farmers’ Markets in London, Deddington, Banbury, Reading and Oxford, as well as to local chefs. For this enterprising couple, small is beautiful. They set up Morten Mushrooms on their 100-acre farm in 1994 and have never looked back.

Because their mushrooms are always harvested on the morning of the Farmers’ Market, they are sought after. Some customers say they are so fresh they can keep them a couple of weeks in a paper bag in the fridge. (Plastic bags will make them sweat).

Compare a button mushroom with a large flat open mushroom and you find the only difference is a few days’ growth and if you want to use fancy names, a big flat chestnut mushroom that can be stuffed and cooked as a meal is a Portabello whereas the baby button chestnuts are Portabellini. Morten Mushrooms also produce a delicious pate and cartons of soup – a use for misshapen mushrooms, so there is absolutely no waste. Richard encourages his customers to buy his freshly harvested crop and have fun experimenting with the many flavours.