Sarah Biren
Sarah Biren
October 11, 2023 ·  5 min read

Harnessing the Power of Nettle Fertilizer Pesticide for Sustainable Agriculture

It’s a weed of many names, including common nettle, stinging nettle, nettle leaf, and burn nettle. But don’t let some of these names scare you. Nettles have six subspecies, and only five sport hollow stinging hairs on the stems and leaves that are painful to touch directly. Nettles are found all over the world, and good thing too. They have been used for food, tea, and traditional medicine for centuries, but their potential uses don’t end there. Nettles can also make an effective and natural fertilizer. 

What are Nettles?

Nettles are herbaceous perennial plants that tend to appear each spring and die down in the winter. They tend to grow in northern Europe, most of Asia, Canada, the United States, northern Mexico, Australia, and South America. They thrive in temperate climates with moist soil. This plant has a similar taste to spinach and is available in the form of tea, although some people cook it into dishes such as soup, pesto, and polenta.

There’s limited research into nettles as a natural remedy. However, there is some evidence showing that nettles contain potential health benefits from its assortment of nutrients including amino acids, minerals, vitamins, and antioxidants. For instance, nettle products might help reduce inflammation and improve hay fever symptoms. But nettles could interact with medications including blood thinners, diuretics, and lithium. Pregnant women should avoid consuming nettles because they can increase the risk of a miscarriage. [1]

Nettles are also a favorite food for many insects, some of which are extremely beneficial to home gardens, like ladybugs and pollinators. But they also contain compounds like histamine, formic acid, and lectins that can serve as a natural pesticide against thrips, spider mites, and aphids. Nettles crave soils rich in nitrogen and phosphorus, so their growth indicates the quality of the surrounding earth. But more than that, nettles themselves contain compounds like nitrogen, magnesium, iron, and sulphur, which can work as a natural fertilizer. It’s best used on young plants to aid their growth but you might want to switch to another fertilizer once they begin to flower to avoid growing lots of foliage with few fruit or blossoms. But you can continue using nettle fertilizer for non-flowering plants such as cabbages and leafy greens. [2]

How to Make Nettle Fertilizer

Step 1: Harvest 

Nettle stings and rashes are harmless but they are uncomfortable, so when you harvest these plants wear thick gloves (preferably made with leather, canvas, or rubber coatings), long sleeves, and pants instead of shorts. Nettles don’t have hard thorns like cacti but rather thin, hollow needles one could brush against without noticing. That is until the itchiness and stinging begins. Use small pruners or scissors to cut off the stalks of the nettles. Pick enough to fill a five-gallon bucket. 

Step 2: Make fertilizer tea

Use hedge clippers or a similar tool to chop up the nettle stalks into a mulch. The mulch should fill about half of the bucket. Now fill the rest of the bucket up with rainwater, or another form of non-chlorinated water, and mix the contents. Next, cover the bucket but don’t seal it. Stir the fermented stalks every couple of days. Look out for bubbling; that’s a sign that the slurry is fermenting. The bad news is that nettle fertilizer tea smells foul, so keep the bucket where the odor won’t bother you. After 10 to 14 days, the nettle slurry will stop bubbling, which is a sign that the fertilizer is ready. Now strain the tea using a strainer, funnel, or cheesecloth. You can use the solids for compost while the liquid is ready to be used in your garden.

Step 3: How to use the fertilizer

Keep in mind, this nettle tea is extremely concentrated, so only use it when diluted with water. Apply the ratio 1:10, or a one cup of fertilizer to 10 cups of water. Next, pour the diluted nettle fertilizer directly to the base of the plants. You can use this fertilizer every three to four weeks but too much exposure can cause fertilizer burn. 

You can also create a foliar spray, using the ratio of 1:20 (one part fertilizer to 20 parts of water). In spray form, nettle tea can ward off pests. However, you will need the ensure the mixture is strained very well, since bits of plant can clog the nozzle of the spray bottle. Remember, don’t spray this on flowering plants. [3]

If you don’t have nearby nettles, you can purchase nettle extract and use the same ratio to dilute it before using it as a fertilizer in your garden.

How to Treat Nettle Stings 

Rashes from nettles often include raised bumps and redness. They may feel like painful stinging before becoming itchy. If someone experiences an allergic reaction, they should seek immediate medical attention. But most cases can be treated at home. Firstly, don’t touch the rash for about 10 minutes after touching the nettles to allow the chemicals to dry. Touching or rubbing the area can push the chemicals into the skin and worsen the reaction. Letting the rash dry makes the compounds easier to wash off with soap and water. 

Next, use tape or a wax strip to remove any needles from the skin. Avoid hot temperatures and scratching the skin since that could worsen the irritation and lead to infection. Instead, use a cool compress for relief, or dab (not rub) aloe vera, creams with hydrocortisone, or a baking soda and water paste onto the area. Speak to a medical practitioner if the rash covers a large area of skin, looks infected, or doesn’t improve within 24 hours. [4]

Sources

  1. What are the health benefits of stinging nettle, and what does it look like?Medical News Today. Aaron Kandola. May 23, 2023
  2. “How to Make Stinging Nettle Fertilizer Tea to Feed Plants.Homestead and Chill. Deanna Cat. August 10, 2023
  3. “Stinging Nettle Fertilizer Tea – Free Organic Fertilizer Made From Weeds.” Rural Sprout. Tracey Besemer. May 11, 2022
  4. “How to Get Rid of Stinging Nettle Rash.Healthline. Becky Young. September 29, 2018