HENRY ASHBY has been foraging for 50 years and is the self-proclaimed Grandfather of the Foragers. A former submariner in Plymouth, six years ago Henry started foraging as a career and making a living from it. A large part of this was working with chef and now friend James Sommerin.

Henry said: “It started with my grandad. We lived out in the Middle East, but I had to come back here for my education.”

There was Big Grandad and Little Grandad, both from Yorkshire and both into foraging.

Henry, 57, who is also a Forestry Commission warden, said: “Big Grandad would take me down the river bank to find mushrooms.

“The other grandad was a hedgerow forager. The first thing he ever gave me was a hawthorn bud. Then he took me out and showed me bilberries.”

This followed a stint in the Scilly isles, where he spent his time shrimping and collecting seaweeds, cockles and sea spinach.

Henry said: “It was a bit like a film, my childhood. I wasn’t into games. To earn pocket money, I used to go out and shoot rabbits and pigeons.”

There’s no shooting these days, just foraging. Leaving his home in Chepstow, our adventure took us to Beachley. First stop – a car park by the army base.

For the amateur, blackberries are a great place to start. There are bush or hedge blackberries, which typically have big, flat leaves and are relatively bland to taste.

Vine blackberries however, on plants with smaller leaves, are much stronger and sourer in flavour. For those not confident on their leaf size, tasting really is the definitive test here. The vine blackberries are much better for cooking with and you wouldn’t need to add lemon or apple to any pie or crumble with these in.

Further down the path, we stopped next to a lone horseradish plant. The long green leaves and distinct flavour make this a safe bet to find. Pick the leaves from the roots and grate the stems for the fiery flavour. According to Henry, horseradish is plentiful in the wild, especially along the A48.

As we walked back to the car, we spotted some orangey-red, jewel-like pendants in a bush next to the blackberries. These are rosehips and won’t be ready for picking until October, when they ripen and are fully red. I nibbled off the end and removed their notorious itching powder. Fruity and sweet, once boiled they can make perfect syrup for desserts.

Something I soon learned while out with Henry, is that wild foods have some great names. ‘Ale hoof’ is the case in hand. This is the plant’s original Anglo-Saxon name and comes from the fact it was the plant used to make beer before hops. Today, it is also known as ground ivy.

A brewery in Caerphilly is actually planning to make some special beer using ale hoof in time for Christmas. It will be called ‘Forager’s Ale’. Henry admitted there’s a fifty-fifty chance of it being nice.

Henry gathers supplies for about four restaurants. He said: “I turn restaurants away.” The day before, he’d been taking kitchen staff from one of the restaurants out mushroom hunting.

Unlike some foragers, Henry is not secretive with his locations. He said: “I show everybody everything. I offer to show people because I know I can always find something.”

And I do not doubt his ability. As we were driving back up the lane, he spotted a mushroom that we went back to. Flat to the ground and no bigger than 8cm in diameter, I was baffled how he saw it among the leaves. This is ‘the miller’ mushroom, given its name due to its flour scent.

Skips the dog is ten years old and goes out foraging every day with Henry. The name for Henry’s company, Wild foods 365, comes from the fact he bet a chef he could pick one mushroom every single day of the year.

“I go out every day, even if I just take the dog out, I can’t stop myself. I can’t really say it’s work, I just love it.”

He often takes people out who want to train as foragers, as well as schoolchildren or Brownies.

Sloe-picking season has begun and though we didn’t spot any on this occasion, they should be around until November. Henry recommends using them to make a sloe sorbet, which he claims was the best sorbet he ever had.

Next stop was under the Severn Bridge, an area that many would dismiss as wasteland. Henry picked a small fern-like leaf called yarrow. This is popular with the chefs, who use it in salads for its unique pinenut taste.

Just a few steps away were charlock and fennel. Pulling the fennel seeds from the top of the plant, you can smell the liquorice before you taste it.

Hogweed is another plant that pops up everywhere come spring. Using the end of the shoot, it tastes similar to asparagus or marrow to cook with. But beware, it is known to smell a lot like marijuana when cooked.

Other edible leaves we came across include plantain – with a hazelnut taste, great for salads – and mallow leaves which, when boiled up, make marshmallow.

A lone elderberry tree stood beneath the bridge, laden with heavy bunches of small berries. These are musty, sharp berries and according to Henry, make the perfect ice-cream sauce, or failing that, wine.

Going back to the car, we drove down to the banks of the River Severn, to forage the mud flats. Here, Henry’s latest recruit, Wayne, met us with a basket full of long stemmed honey fungus mushrooms he’d just found in some nearby woodland.

A must for all foragers, especially mushroom hunters, is a wicker basket.

Henry said: “You must use a basket. If you use plastic carrier bags, they’ll all go to mush.”

Among the rocks on the muddy riverbank are plenty of sea blights. Rubbery in texture and quite flat to the rocks, this looks and tastes very much like samphire, the salty green that is a must for any on-trend chef and now found on the shelves of Waitrose.

There are also plenty of long, green, sea spinach leaves.

“The chefs like this, as it won’t wilt like normal spinach and can last up to a week,” Henry explained.

So many of the leaves found here go into what some of the chefs dub ‘Salt Marsh Salad,’ to avoid using the unfamiliar names.

“Everything apart from the grass here is edible.” And we went on to find sea asters, more elderberries and even baby acorns.

But one type of grass is edible. The long strands of sea arrow grass are easy to find and pick all year round and are a great substitute for coriander.

This year, Henry has been nominated for a food tourism award in the upcoming Monmouthshire Business Awards.

What’s clear from my hours out with Henry is that foraging blind isn’t a good idea. For novices, he can recommend two books: Richard Mabey’s Food for Free and Rodger Phillips’ Wild Food.

“Between the two of those, that will start you off really well.”

But there are serious dangers. There’s a ten per cent chance of survival with certain mushrooms.

“If you have any doubt, leave it alone – especially fungi. The deadly lookalikes aren’t worth trying. You have to know what you’re doing.”

Henry believes wild food plays a significant part in making Monmouthshire a centre for food and has big plans for the future, when he hopes to convert his garage into a place to train sous chefs how to cook and prepare foraged food.

There’s no one ‘best’ area, but the coast, moors, fields and woodlands of Gwent are all ideal for exploring. Even after years of foraging, Henry is confident he will always find more.

“Not one forager will ever know everything,” said Henry. So let the hunting begin.

Follow Henry on Twitter @wildfood365 for tips and advice.