Hitching a ride in the pockets of Roman soldiers, walnuts made their way to British Isles in the 16th century – the good old days when walnut trees were considered rather valuable and made regular appearances on the family inheritance list. It didn’t take long for this tough nut to crack to become a worldwide kitchen table star; it’s currently ranked the second most popular nut after the almond.
Although the English Walnut does not technically grow wild in Northern Europe, you can find many feral trees across the UK, thanks to squirrels inadvertently forgetting where they have buried their nut stash. Walnuts are ripe for the picking in early September but reach their full-flavoured splendour in October.
However, you don’t have to wait until then to enjoy this delicious nut as it can be picked while it’s still young and unripe. And although, the green walnut is best picked in June/July, the rather mild summer we’ve had this year has prolonged the season and juvenile walnuts can still be found in abundance along public footpaths, hedgerows and waste ground. The green (aka wet) walnut is superb pickled into the English delicacy or steeped into a famous Italian/French lush dark brown, espresso-like liqueur.
Seasonal period: Midsummer to early autumn
Where to find them: Waste ground, hedgerows, public footpaths
How to recognise: Tall and wide-spreading, the walnut tree can reach up to 50m high. It has a grey, dark brown furrowed bark and large pinnate leaves which have 5-9 elliptic, glossy leaflets with prominent midribs and veins. The smell of a crushed leaf is highly aromatic. The twigs have a central pith divided into chambers, and distinctive Y-shaped scars where the leaves have fallen.
Male flowers are in catkins, female flowers in short, spike-like clusters of 2–5 on the same tree. The fruit are 3.5–5cm long, globe-shaped or slightly pear-shaped. The nuts are covered by a hard green, fleshy husk when unripe and is notorious for staining everything in close proximity when removed, so make sure to wear gloves and do it outside. This husk changes to a brownish colour when it ripens and looks like two halves of the brain. They tend to split when dry, making it much easier to remove the nut inside with a nutcracker.
What to eat: The nuts!
Cleaning and storing: Green walnuts can be washed and then pickled or steeped in alcohol. The ripe unshelled nuts can be washed and then either hulled or dried for later use. Make sure they are completely dry before storing, they go mouldy when wet. They store for up to a year if kept in a airtight container in a cool, dark cupboard.
Cooking: Green walnuts can be pickled or steeped in alcohol or (see recipes below). The dried nuts can be eaten raw – enjoyed as a snack, thrown into salads, blended into a pesto, added to cakes, biscuits or pies. The mild tasting but nutty tones are encouraged by toasting.
Toasting: Place the nuts on a baking sheet in a single layer and bake on medium heat for 10-15 minutes. They are ready when they turn a golden colour.
Medicinal uses: Walnuts are rich in antioxidants, omega-3 and 6 fatty acids, and they are a natural source of manganese which maintains healthy cells and strong bones. They help reduce inflammation, lower cholesterol and even reduce heart disease. The leaves and root bark are used in anti-parasitic preparations and used to treat a range of skin diseases from herpes to eczema. Taken internally, it can stop diarrhoea.
Other uses: The hulls, husks, leaves and bark are all used as vegetable dye and produce a colour rich in tannins ranging from yellow to dark brown or black. The oil has been used for oil paints as an alternative to Linseed oil.
Know hazards: As with all nuts, people who are allergic should stay far away from walnuts.
Remember to always wear gloves when handling walnuts – especially when they are still green as they will stain your skin and everything else.
Responsible foraging: Unless you are 100% sure of what it is and 100% sure that it is edible, DON’T EAT IT! Harvest only what you need from large, healthy trees. Consider pesticides, herbicides and pollutions. Think about all that could, might and will have drifted onto the trees and pick wisely.