Organic and environmentally friendly gardening is becoming increasingly popular among hobby gardeners. One of the oldest natural aids is the stinging nettle. Even if you don't really like seeing them in beds and most would rather ban them from the garden, they have many positive qualities. It is not for nothing that nettle brew, which is easy to produce, is considered the gardener's liquid gold. In the right dosage, it is a very good natural fertilizer and can repel pests.
nettle brew
Nettle stock or nettle manure?
When making a brew or liquid manure from nettles, the mixing ratio is less important than the time it takes for the fermentation process to start. While a brew is ready for use after 12-24 hours, a liquid manure takes an average of 2-3 weeks, depending on the intended use. The latter is usually only used diluted. Used undiluted on plants, it would burn them. When making a brew, the stinging nettle is not expelled, i.e. it is less pungent and therefore gentler on plants, for example when used to combat pests.
Prepare nettle stock
Harvest of the plant material
First, the required nettles are harvested. Both the large nettle (Urtica dioica) and the small nettle (Urtica urens) are suitable, with the latter supposed to have a more intense effect. They can be harvested to make a suitable brew before they bloom, i.e. between May and July. It is best to use only the leaves. The entire plants without the roots can also be used for liquid manure. To remove the leaves from the stems, it is advisable to wear gloves that cover the forearms as long as possible to protect yourself from the very unpleasant stinging hairs. In addition to fresh, dried nettles can also be used to prepare a brew.
Harvest nettles
Tip: Since nettle stock is often needed later in the year, it makes sense to dry some of the nettles. If necessary, a corresponding brew can then be made from them.
The right vessel
The vessel in question for making a brew should be heat-resistant and, above all, large enough so that the nettle brew does not overflow during fermentation. It can be made of wood, stone or plastic. Metal vessels are completely unsuitable, as the fermentation process can lead to different chemical reactions.
Instructions for preparing a brew
In addition to the appropriate herbs and a suitable vessel, you need hot water, a wooden spoon to stir the mixture and a kitchen sieve to make a broth from stinging nettles. Then you can start.
- first place a bucket or vat in a sunny spot
- location in full sun is important to speed up the fermentation process
- Half shade or shade less suitable
- Now fill the container with fresh nettle leaves
- You can also use dried herbs instead of fresh ones
- Calculate about 500 g fresh or 75 to 100 g dried herbs for 5 liters of water
- use rainwater if possible
- then heat the water or bring it to a boil
- then pour the boiling water over the herbs
- mix well and cover the jar
- Cover should be loose and not airtight
- allow the prepared brew to steep for about 24 hours
A brew usually does not have an intense smell, such as when stinging nettle manure. After these 24 hours, the mixture is poured off through a sieve.
Tip: If the brew is to be applied later using a spray bottle, the sieve would have to be correspondingly finer in order not to clog the spray nozzles. If, on the other hand, it is applied with a watering can, the sieve can also be coarser.
use
For foliar fertilization
Deficiency symptoms in plants can be remedied with foliar fertilization. If the leaves show brown and/or yellow discoloration with protruding green leaf veins, there is a high probability of leaf chlorosis. For example, an excess of lime in the soil can prevent important nutrients from being transported within the plant, causing it to suffer from a deficiency.
Use spray bottle
An excess of lime can occur, for example, if plants that actually prefer a rather acidic soil are increasingly watered with calcareous tap water. In these cases, foliar fertilization with a stinging nettle broth is a good idea. The solution is preferably applied to the leaves early in the morning or in the evening using a spray bottle. At the same time as foliar fertilization, the cause of the excess lime must be found and remedied accordingly, if necessary by changing the location or substrate.
For pest control
Nettle stock is a tried and tested means of repelling certain pests. These include aphids, spider mites and thrips. The effect of the brew is based on the dissolved nettle toxins, which are present here in a very high concentration. It is best to apply the brew undiluted, then the effect is most effective.
In the case of a stronger infestation, the treatment usually has to be repeated after two days, if necessary several times. If you want to be on the safe side, you should continue the treatment until no more pests can be seen on the plants. In the case of an initial infestation, a single treatment is often sufficient.
Nettle brew too weak for conventional fertilization
The stinging nettle is extremely popular with hobby gardeners because of its very good fertilizing properties. With the exception of foliar fertilization, a stinging nettle broth is not strong enough for conventional fertilization, then it should be liquid manure. The production of nettle manure is a bit more complex but definitely worth it. Basically, the preparation of a liquid manure is similar to that of a brew, although a larger amount is usually required here.
- prepare about 1000 g of fresh plant material with 10 l of water
- alternatively use 200 g dried herbs
- place the septic tank in as sunny a position as possible
- choose a place where the intense smell does not bother you
- then cover the septic tank with a grid so that oxygen can get to the mixture
- Oxygen supply is a prerequisite for starting the fermentation process
- after approx. 2-3 days foam forms on the mixture
- the fermentation process has started
- at the same time, an extremely unpleasant odor develops
- now stir the fermentation material daily
- Reduce odor by adding rock flour or bentonite
- Bentonite is a mixture of different clay materials
- Slurry is ready when the brown brew stops foaming
nettle brew
You pour them through a sieve and put the whole thing in a shady and cooler place to prevent secondary fermentation. The nettle liquid manure can now be used diluted accordingly. The plant remains can be disposed of very well on the compost heap, where they, like the finished manure, make an optimal composter. Due to its high nitrogen content and the proportion of potassium, the finished liquid manure, diluted accordingly, is very suitable for fertilizing so-called heavy consumers. These include tomatoes, cucumbers, peppers, Brussels sprouts, rhubarb or zucchini. On the other hand, weak consumers such as flowers, vegetables and fruit trees do not tolerate nettle manure.
durability and storage
While stinging nettle brew should be used up within a day at the latest, stinging nettle slurry can be kept almost indefinitely. However, this assumes that it is strained, covered with an air-permeable cover and kept in a shady and cool place outside.