An autumn foraging walk in the Greyling Hills, and the rules every forager should follow

On a damp Sunday morning in the woods above Tarnmere, a group of fourteen walkers follows Imelda Cartwright along a muddy path, baskets in hand. Every so often she stops, crouches and points: a rosehip here, a cluster of late blackberries there, a scatter of sweet chestnuts on the path. A forager and countryside ranger for twenty years, Ms Cartwright leads guided walks in the Greyling Hills every weekend in autumn.

This has been a generous year for fruit and nuts after a warm late summer. Blackberries are still found in sunny spots, rosehips make a syrup rich in vitamin C, and sweet chestnuts are falling from the old trees near the reservoir. Hazelnuts and sloes are also around, though sloes are best picked after the first frost.

Mushrooms: look, do not eat

The woods are also full of fungi, and this is where Ms Cartwright becomes firm. Her walks are about looking, photographing and learning, not picking mushrooms for the table. Several deadly species grow in the Greyling Hills and can look very similar to edible ones, and there is no simple test that tells them apart.

Never eat a wild mushroom unless an expert has identified it with complete certainty. If there is any doubt at all, leave it where it is.

Dr Saoirse Lindqvist of the regional poisons advice service said that every autumn people became seriously ill after eating mushrooms identified from apps or photographs. Symptoms of some poisonings may not appear for many hours. Anyone who has eaten a wild mushroom and feels unwell should seek medical help immediately and, if possible, take a sample of the mushroom with them.

For all foraging, the basic rules are the same: take only what you can use, leave plenty for wildlife, avoid roadsides and sprayed field edges, and do not dig up plants. In parts of the Greyling Hills nature reserve, picking is not allowed at all. Ms Cartwright's walks run until mid-November, cost €10, and should be booked through the Tarnmere visitor centre.