No, no, not the nettles! – Dilo de Alwis

“Ouch, Ouch”, squealed my grand daughter 3 year old Eva, “they stung me!”. “Those are Nettles”, chortled her elder brother, “grand dad grows Nettles!”. “Why, granddad? Why do you grow Nettles?” asked Eva, indignantly. “They are horrible!”.

Nettles have long been reviled, and hunted down as evil weeds in our gardens. We have all been stung by them and gardeners have fought with their extensive root systems. With the burgeoning movement towards organic gardening, we are beginning to recognise that nettles are not the enemy, but an important ally in our garden and environment.

Lets start with insects. Many butterflies and moths depend on nettles as a vital source of food for their caterpillars. These include the tortoiseshell, the comma and the peacock. Leaving patches of nettles will help to protect these species. Additionally, if they lay eggs on the nettles, then your vegetables and flowers will be less likely to be attacked by caterpillars.

More than forty other species of insects live on nettles. Aphids are attracted to nettles and this will keep them from your fruit and vegetable plants. In turn, Aphids will  attract  natural predators such as lady birds, damsel flies and hover flies to your garden.

Many insects are keystone species and their decline affects the entire ecosystem. To quote Sir David Attenborough, “If we and the rest of the back-boned animals were to disappear overnight, the rest of the world would get on pretty well. But, if the invertebrates were to disappear, the world’s ecosystems would collapse”. Just leaving a patch of nettles is a simple and effective step we can all take to help our threatened world.

All the insect life around nettle patches also provide food for frogs, toads, hedgehogs and shrews.

Nettles produce large quantities of seeds that are a good source of food for house sparrows, chaffinches, and bullfinches.

We too can benefit from nettles. They can be eaten: the fresh tips can be used like spinach and cooked in a variety of dishes, and also made into teas and soups. There are many recipes on the internet. Nettles also make a rich, deep green dye that can be used as on organic food colour.

There are nutritional benefits to eating nettles. They are rich in minerals such as calcium, iron, magnesium, phosphorus, potassium and sodium. Additionally, they contain significant amounts of vitamins including A, C and K. Nettles also contain many beneficial antioxidant pigments and polyphenols, although probably not in significant levels compared to dark coloured fruits and vegetables such as beetroot, carrots, plums etc.

Less well supported by good research are the various health benefits and medicinal recommendations. A quick search on the internet will throw up wonderful lists of diseases that can be treated with nettle formulations but there is little robust evidence to support many of these claims.

Gardeners too can benefit from preserving a patch of nettles. By having an extensive and deep root system, nettles are more efficient than most vegetables and flowers in absorbing minerals from the soil. This fact has been used by some canny gardeners who use nettles as nutrient-rich, organic, fertilisers.

Traditionally, gardeners have crushed or shredded nettles which are steeped in water, allowing them to rot. This “nettle tea”, however, stinks (as does the much venerated Comfrey tea). When the liquid stops stinking, it’s ready to be added to your plants in a much diluted form as an efficient liquid fertiliser.

A better way, minus the stink, is to ferment the nettles by adding some sugar to the mix – it’s also faster. There is a lot of lore about the exact way to do this and makes for interesting debate

As for me, my technique is based on the same principles as making Kim-chi or other fermented foods. Use three parts of crushed or shredded leaves to two parts of brown sugar. I put all of this with a little rain water (or bottled still water – chlorinated water will hinder the organisms that produce fermentation) into a liquidiser.  Once you have a thick mush, decant into a bottle and place a weight on top of the material to hold it down so that all of the bits remain within the liquid. This prevents moulds forming on top. You can get fermentation jars with glass or ceramic weights from Amazon or other retailers. You can use a stone as the weight but best sterilise it first by steeping in boiling water for a few minutes. Leave the mix in a warm dark place for at least a week. Then mix in a ratio of one part to ten parts of water to apply to your plants. Leave a little behind to add to the next batch as the active culture of organisms will kick-start the process.

This diluted nettle fertiliser is supposed to work well as a foliar feed but I am not convinced of the science behind foliar feeding. I add it directly to the soil.

Interestingly, several other “weeds” including dock and dandelions are also packed with minerals as their deep root systems extract nutrients that cannot be reached by the shallower roots of most vegetables and annual flowers. They too can be fermented into similar feeds, either on their own or as a mixture.

It is important to understand that both rotting and fermentation does not increase the amount of minerals and other nutrients, but simply makes it available in a form that can be readily absorbed by plants. If you just mash up the leaves and add to the soil around you plants, they will extract the same nutrients as the nettle leaves breakdown, albeit over a longer time.

Cut and Drop, a gardening technique backed by science and gaining momentum, simply involves snipping your weeds and letting them fall on the ground, returning the nutrients to the top soil, making them accessible for your flower or vegetable plants.

If you continue to harvest the same patch of nettles many time over, however, you will exhaust the mineral and nutrient content of that patch of earth. So I would suggest that you keep your patch of nettles for the wildlife in your garden but harvest nettles sparingly on your countryside walks, avoiding using the same patches each time. Given time, natural decomposition will return nutrients to the soil and you can return to the same patch after a year or so.

So the next time you reach for those gloves and a fork, take a moment to consider this unsung hero. Preserving a patch of nettles in your garden is another little thing that can save our ailing Earth.

Dilo de Alwis