If you have a lot of stinging nettles in your garden or in your neighborhood, then you. are. in luck! There are a lot of different things you can do with stinging nettles. You can eat them, use them for self care, and… you can use them to make ‘plant fertilizer’. Read on to find out how to make nettle ‘plant fertilizer’.
Like dandelions, nettles used to be an annoying weed that invaded our garden. But lately I have found so many uses for them. Once I started to dive into this ‘foraging world’, I saw numerous possibilities. My most recent go at foraging and making something fun with my harvest were these dandelion cookies. With the stinging nettles, however, I knew straight away that the first thing I wanted to make was this plant fertilizer; because it is apparently really simple to make, and who doesn’t want a bit of ‘free’ help to improve their crops?
The benefits of using stinging nettles as fertilizer
Apparently stinging nettle belongs to a special group of plants called ‘dynamic accumulators’. ‘Dynamic accumulators’ take up nutrients and minerals from the soil, and then store them in highly bio-available forms and concentrations in their leaves. This makes them ideal to add to botanical teas, homemade fertilizers, mulch, or even to your garden compost pile.
There have been scientific studies which show that fresh stinging nettle leaves are loaded with high concentrations of vitamins as well as large amounts of minerals. The leaves are also high in nitrogen, chlorophyll and plant polyphenols. If those terms confuse you a bit, don’t worry they confuse me. The main thing we can take away from this is that those elements all support plant health and stimulate growth. And that’s what we want!
What do you need
- Stinging nettles
- Thick (pruning) gloves that won’t allow you to get stung
- Trimming shears or scissors
- Water, preferably without chlorine. Rain water is ideal. If you only have tap water, then just let the water sit in a bucket in the sun for 24 hours. That should allow the chlorine to dissolve.
- Bucket with lid
- Stir stick
- A mesh strainer, cheesecloth, or anything that could help you to strain the plant fertilizer
How to make the fertilizer?
Before you start, I have to give you a heads-up. This plant fertilizer stinks. Bad. So when you make it, make sure to set it up somewhere outside or in a shed where you wouldn’t mind the smell.
1. Collect your nettles. You can decide how much of course, but I decided to fill two buckets. With the trimming shears remove the three or four top pairs of leaves of each nettle plant, since they contain the most vitamins and minerals. Make sure that you avoid picking them near a road or other area where they may have been sprayed with chemicals.
2. Put the nettle in the bucket with lid in which you wish to store the plant fertilizer during the fermentation process. I decided to use an old rain barrel which I had lying around. After filling it, I discovered that it was leaking on one side, hence the barrel lying on its side! Chop the nettles into smaller pieces with your shears. Finer pieces will result in better fermentation and nutrient release.
3. Add sufficient water to cover the nettle in the bucket. You should be able to stir it easily and it must not be too thick.
4. Place the lid on top of the bucket but don’t seal it.
5. Stir the brewing plant fertilizer once a day if possible. Bubbles should appear when you stir it. This is a good sign; it means that it’s fermenting! The bubbles didn’t appear with me until after four days.
6. After one to three weeks the fermentation process should be complete. You’ll know that the mixture is ready when bubbles cease, as it were, after stirring.
7. Strain the nettle solids from the mixture. I strained it using a mesh strainer into this unused drink dispenser. I used this drink dispenser since I didn’t have any buckets with lids around and I wanted to avoid buying something new. If you do have a bucket with a lid – or anything similar – go for that. The ‘leftover solids’ are ideal for your compost pile! The stinging nettle plant fertilizer will keep for around six months.
8. When you plan to use the plant fertilizer for your garden, you will have to dilute it with water. It is recommended that you use one part fertilizer to 10 parts water for watering plants, and 1:20 for direct foliar application (with a spray bottle).
Direct foliar application means that the fertilizer is applied directly to the plant’s leaves as opposed to putting it in the soil. Why would you do that? A plant takes nutrients through the leaf much quicker than it does through the root and stem. Foliar application can be beneficial when a plant is suffering from certain nutrient deficiencies. However, it’s not meant to be a substitution for healthy soil. Another good benefit of this technique is that the smell of the plant fertilizer works as a strong insect repellent.
Only apply this plant fertilizer about once every month.
9. Last but not least, it’s important to remember that not all plants will benefit from this particular plant fertilizer. I will admit, I have researched online which plants will benefit from this plant fertilizer and it was a bit confusing. Different things were being said.
The following statement on this website seems to sum it up well; it works best on leafy plants and heavy feeders. Heavy feeders are for example: sunflowers, aubergine, peppers, tomatoes, corn, cucumbers, cantaloupes, pumpkins, gourds, winter squash, courgette and all types of melons.
Another website added to it: This fertilizer works best on plants that have a high demand for nourishment such as fruit trees and bushes, roses, annuals and perennial flowering plants. It works for tomatoes, leeks, brassicas, cucumbers and courgettes. However, it is not meant for beans, peas, onions, potatoes and root vegetables.
The third and last website I am going to refer to added: Your ornamental and crop plants will profit from this, without the necessity of using chemical additives… Only for the usage with salads, peas, cabbage or vegetables the usage of stinging nettle manure is not suited.
Guess what… I added it to my lettuce before I found that last bit of information! Oops! Let’s hope they don’t die. It has become clear to me that the use of this plant fertilizer will be a bit of a learning curve. I will make sure to keep you up to date if I learn anything new!
Do share in the comments if you have any clear sources on which plants can handle this plant fertilizer. Also, are you going to give this plant fertilizer a go? Or have you already made it before?