Last Updated on August 10, 2023
It is almost spring, and that means the nettles are on their way! Do stinging nettles grow rampantly in your area? If so, you’re in luck. Because that means you have an abundance of free and fabulous fertilizer – right at your fingertips! Uh, gloved fingertips that is. Read along to learn about the benefits of stinging nettle, how to comfortably harvest it, and how to turn it into homemade fermented nettle fertilizer tea. The other plants in your garden will thrive in return!
What is Stinging Nettle?
Stinging nettle (Urtica dioica, also known as common nettle or nettle leaf) is an herbaceous perennial plant. It usually pops up each spring, and easily spreads after flowering and going to seed. Nettle is native to Europe but now grows in damp fertile soils virtually throughout the world. If you’re foraging for wild nettles, look in shady and moist locations like along creeks.
Stinging nettle is often considered a “weed” due to its promiscuous growth habits. It also catches a bad wrap as a bully (admittedly justified) by causing a painful itching and burning sensation to those who come in contact with the sharp hairs that cover its leaves. An inflammatory nettle rash is uncomfortable, but temporary and not dangerous. Furthermore, after reading about the stellar benefits of stinging nettle, perhaps you’ll realize that nettle can be even more of an asset than a nuisance!
Health benefits of stinging nettle
Herbalists, naturopaths, and many organic gardeners recognize stinging nettle as a favorable plant to have around – given its numerous and well-researched healing properties. Compounds found in nettle make it excellent at fighting bacterial infections, reducing inflammation and arthritis, relieving pain, easing allergy symptoms, stabilizing blood sugar levels, and more. In fact, this natural nettle quercetin is the only “allergy pill” I take – and I am quite sensitive to environmental allergens!
How to prepare fresh stinging nettles
In order to reap the benefits of stinging nettle, they need to be “de-stung” first. (That is, if you want to consume them yourself). The best and easiest way to prepare fresh stinging nettle is to blanch them in water. The brief exposure to high heat neutralizes the stinging hairs. Rinse them afterwards, which doubles as washing them as well.
Now, you can enjoy the blanched and rinsed nettles fresh, juiced, added to soup, frozen, or dehydrated into tea or powder for later use. Nettles are delicious and earthy, like a cross between spinach and arugula. I suggest sautéing them in EVOO with salt, pepper, and even a little garlic or onion – much like you would kale or other leafy greens.
Okay, that is all fine and dandy… but isn’t this article about stinging nettle fertilizer? How does nettle benefit other plants?
Why Make Stinging Nettle Fertilizer Tea
As a vegetarian and avid organic gardener, I find it extremely rewarding to be able to create our own free and natural plant-based fertilizers. Plants feeding plants, if you will. For example, by making various botanical teas or fermented plant juice – which is what we are doing today. The process is even better when the plant ingredients come from our garden, or can be foraged for locally! We also like to routinely feed our seedlings, newly-planted trees and other plants with homemade aloe vera soil drench. Of course, composting at home is the ultimate way to create free organic fertilizer.
The benefits of stinging nettle fertilizer for plants
Stinging nettle belongs to a special group of plants referred to as “dynamic accumulators”, which also includes yarrow, borage, fava beans, comfrey, dandelion, miner’s lettuce, and chickweed. Those “dynamic accumulators” readily take up nutrients and minerals from the soil, and then store them in highly bioavailable forms and concentrations in their leaves. This makes nettles (and all other dynamic accumulators!) an excellent nutrient-rich addition to botanical teas, homemade fertilizers, mulch, or to a compost pile.
Scientific studies show that fresh stinging nettles leaves are loaded with high concentrations of vitamins A, C, D, E, F, K, P, and vitamin B-complexes, as well as large amounts of minerals including calcium, selenium, zinc, iron, magnesium and more. As a leafy green, stinging nettle is also high in nitrogen, chlorophyll, and plant polyphenols – all of which bolster plant health and stimulate growth. Plant polyphenols in particular are potent antioxidants, fight cancer, and boost the immune system.
While plants may not get arthritis or cancer in the same way humans do, plants do have an immune system – and can get sick! Therefore, the same compounds that make nettle awesome for human health provide many of the same benefits to plants. For example, plants treated with stinging nettle fertilizer are less susceptible to certain diseases due to nettles’ anti-bacterial and anti-fungal properties. Plants with a strong immune system are also less negatively impacted by pests or stress, such as drought, heat, or other unfavorable conditions.
SUPPLIES NEEDED TO MAKE NETTLE FERTILIZER TEA
- Stinging Nettle
- Prick-proof gloves. Thick leather pruning gloves (or similar leather alternative) are especially protective against thorns and nettles.
- Trimming shears or scissors
- Water, preferably un-chlorinated – such as collected rain water. To dechlorinate city tap water, either allow it to sit out in the sun in a bucket for 24 hours to allow the chlorine to dissipate, or use a carbon hose filter.
- Bucket with lid
- Stir stick
I will go ahead and air the dirty laundry now: fermented stinging nettle tea fertilizer stinks. Big time! So much so, that it’s sometimes referred to as “nettle manure”. Or as I like to call it: Stinking Nettle Tea. Therefore, I strongly suggest you make your stinging nettle fertilizer outside somewhere and not in your garage or house. Please don’t let the funky aroma dissuade you from making nettle tea! But don’t say I didn’t warn you.
Steps to Make Stinging Nettle Fertilizer Tea
- Collect nettle in a bucket. We typically loosely fill a 5-gallon bucket. To harvest stinging nettle, you can either pull it out by the roots (if you don’t want it to grow back this season) or use scissors/shears to trim it instead. Wear gloves to protect yourself!
- In the bucket, chop the nettle into smaller pieces. Finer pieces equals more surface area for fermentation and the release of nutrients.
- Add enough water to cover the nettle in the bucket. It should be able to stir freely and not be overly thick.
- Set the lid on top of the bucket, but don’t seal it.
- Stir the brewing nettle tea once per day if possible. Bubbles should appear as you stir it.
- After one to two weeks, the nettle tea is finished brewing. A good signal that your fertilizer is ready is when it stops visibly bubbling after stirring. That means the nettle is no longer actively fermenting.
- Strain the nettle solids from the tea liquid. We do this by pouring the solution through a funnel lined with a reusable paint strainer (which we use to brew actively aerated compost tea) into another bucket. Compost the leftover strained solids.
- Store the finished concentrated stinging nettle tea in a bucket with a lid. Nettle tea fertilizer must be diluted before it is applied to the garden! Read instructions below.
- Use brewed nettle tea fertilizer within about 6 months.
How to Use Stinging Nettle Tea as Fertilizer
Nettle tea is very potent, and therefore needs to be watered down before using it to feed other plants in your garden. To dilute it into a usable fertilizer, mix 1 part brewed nettle tea to 10 parts water. For example, one quart of nettle tea to 10 quarts of water. We find it easiest to dilute and mix a small portion of nettle fertilizer in a separate container as-needed (immediately before use), rather than diluting a huge batch and storing it all.
Nettle tea soil drench
After diluting, simply water your plants of choice with it as a “soil drench”, much like you would with other liquid fertilizers. The recommended dose depends on the size of the plant or container. A smaller plant or pot will be happy with just a cup or two. To feed larger plants or an entire raised garden bed with nettle tea, try applying it with a watering can evenly across the soil. When in doubt, start with smaller feedings, see how the plants respond, and go from there.
Feel free to repeat nettle fertilizer tea applications once every month or two, but not more often than every 3 weeks. Because of the odor, I personally avoid using nettle tea to feed houseplants – though it can be done! I stick to using compost tea or dilute seaweed extract indoors.
How to use stinging nettle tea foliar spray
In addition to feeding the soil and roots, you can also spray diluted nettle tea onto a plant’s leaves. When applied as a foliar spray, stinging nettle tea works as a strong insect repellent. The active compounds in stinging nettles are reported to deter aphids, mites, and thrips. Even more, plants readily absorb nutrients through the leaves, entering their vascular systems even more quickly than those taken up by their roots.
To make nettle foliar spray, be sure that your brewed nettle tea has been strained very well with a fine mesh strainer. Otherwise, leftover plant material will easily clog your sprayer. This time, dilute 1 part nettle tea to 20 parts water and add it to your sprayer of choice. It is best practice to apply any type of foliar sprays in the evening hours once the plant is out of direct sun. This reduces the risk of sunburn to wet leaves, and is the time when beneficial insects are least active. Spray the leaves until they’re thoroughly coated and dripping.
Due to the funky odor, we generally avoid spraying leafy greens like kale or lettuce with nettle tea. Or, directly on to fruit and veggies. However, nettle tea foliar spray is excellent for things like hemp (before flowering), ornamental plants, or tomatoes, peppers, eggplant or fruit trees – before their fruit appears.
So simple, right?
In summary, plants that receive stinging nettle fertilizer tea will experience increased growth and resilience! Making your own nettle tea with homegrown or wild nettles is free, sustainable, and easy to do. I hope you enjoyed this article, and feel excited to go hunt down some nettles of your own! Please feel free to ask questions in the comments below, and spread the nettle love by sharing this article.