Among the natural insecticides, one of the most important for the family garden is the nettle macerate, because in addition to being completely biological could be self-produced quite simply, with great economic savings compared to the pesticides found on the market.
Nettles are a very common spontaneous herb and very easy to recognize, which is why they are an easily available ingredient for making a biological and economical pesticide, which does not require a license for use. Nettle leaves are stinging and contain formic acid is salicylic acid, properties that we are going to use against parasites.
In addition to the use of insecticides always from macerated nettle we can make a fertilizer. The recipe is very simple: just leave the leaves to soak for a longer period of time to extract the many useful substances of the plant and make them available to the plants as foliar fertilization.
As you may have guessed, the nettle really is an important plant essence for natural cultivation, we see below where to collect it, how to prepare its macerates, with dosages and directions for use.
How to prepare the nettle macerate
There nettle macerate recipe is really very simple, timing and dosages are indicative. The following are the recipes and periods that I use, but it is also possible to use different quantities of plants, obtaining a more or less diluted product. In preparation it is important to define whether we want to achieve an insecticide or fertilizer, given that the infusion times depend on this.
I will leave some general precautions implied but those who are more inexperienced can find them in the general article on how to prepare natural macerates for use in the garden.
The insecticidal nettle macerate
The preparation of the insecticide macerate, which we will call short macerated, it's really simple: you need about a kilo of nettle plants cut at the base (the roots are not needed for the preparation), which we must leave to macerate in 10 liters of water. The water is better if it is rain, if you really use that from the water supply, let it settle a few hours after removing it from the tap, so that it loses some volatile disinfectants (especially chlorine). The use of fresh plants is to be preferred, but failing that we can also macerate dry leaves, in this case the ratio becomes 100 grams per 10 liters.
To obtain an insecticidal macerate the infusion time is one or two days, after which the mixture must be filtered and is ready to use, sprinkling it on the plants without dilution.
One of the side effects of this preparation is certainly hers pestilential stench, unwelcome to insects but also to humans. It is worth bearing it, considering how much nettle macerate is useful for the organic garden.
Macerate of nettle fertilizer
From nettles you can also get a fertilizer, leaving them to macerate for longer than the two days we considered for the insecticide. Nettle leaves contain useful substances such as nitrogen, magnesium and iron, for which we will obtain a precious liquid organic fertilizer.
The dosage is identical to that of short macerate, then 100 grams per liter in the case of fresh plants, or 10 grams of dry leaves. What varies is the infusion period, in fact for the fertilizer we have to leave to macerate for 10/15 days.
Find and recognize nettles
If we want to prepare the macerate for free we must be able to find and recognize the nettle plants in nature, going to pick them. First you better know that the best time to do it is before the plants bloom, because flowering involves a waste of energy and nutrients that impoverish the properties of the plant. However, it happens that you have to adapt to what you find and the macerate has its effectiveness even if you catch nettles in bloom.
Nettles are a spontaneous plant, easily recognizable in appearance: the emerald green leaves with serrated edges are characteristic. To remove any doubt, even if it is unpleasant, we can try to touch a leaf, which is covered with stinging hairs. If we feel the classic sting, we have almost certainly identified the right plant.
Once the nettle has been identified, it is worthwhile use gloves for collection, so as not to find the hands covered with irritation.
The nettle plant prefers soils capable of retaining moisture and very rich in organic matter and nitrogen. If we want to know where to find it, let's take it into account: we can look for it in uncultivated areas of partial shade, perhaps frequented by animals that with their manure provide the elements loved by this spontaneous herb.
Preservation of the insecticide
The short nettle macerate is kept for little, after a few days it loses its effectiveness, so it is best to prepare it just before use.
Use of the insecticide macerate
How insecticide the nettle infusion is excellent in particular against plant lice (aphids is cochineal), as well as being a product acaricide so perfect for fighting the red spider. Its effect is largely due to formic acid. substance that makes nettle leaves sting. On many other animal parasites, for example against some lepidoptera as the moth or against the diptera afflicting the orchard, however, has a repellent effect, while it doesn't work against cabbage, which indeed seems to be attracted to the nettles. In any case, it is a useful insecticide if used at the beginning of infestations, as it struggles to effectively counteract a significant settlement of parasites.
Use is very simple, it works spraying the preparation on the whole aerial part of the crops to be protected. We can repeat the treatment after 4 or 5 days, to best eliminate the parasites. We avoid doing treatments in the hottest and sunniest hours.
We can do and preventive treatments than to free us from an infestation already in progress, in this second case it is better to repeat the treatment after 4 or 5 days with a second pass, to eliminate a greater number of parasites.
Precautions and waiting time
We recommend two precautions when using this organic insecticide: the first is to be careful where you leave the bin with the macerated product, because the stench could annoy the neighbors, especially if you do the long maceration.
The second, more serious, is of pay attention because the nettle macerate annoys all insects, even those that are useful for the vegetable garden: it is slightly toxic, for example for bees. As a shortage period, we recommend letting 5 days pass, however it is a pesticide that has no impact on the environment and naturally degrades.
The fertilizer nettle
The long macerate of nettle is used as valuable fertilizer, thanks above all to the rich presence of nitrogen, and also to replenish iron is magnesium. After preparing it, we can dilute it one to ten and use it as irrigation water for the garden.
A particularly valid use is in pot cultivation, given that a limited soil offers less nutrients to crops and requires more frequent fertilization.
The macerate also has an effect of strengthen the natural defenses of plants against some pathogens, due to the salicylic acid present in the tissues of the nettle: powdery mildew, peach blister, downy mildew of tomatoes and potatoes. It is not a decisive treatment but it helps in prevention. For this use it is better to macerate fertilizer.
There are those who also use the long macerate of nettle on the seedlings at the time of transplant, wetting the roots, and who considers nettles a good acomposting activator.
Buy nettle extract
If you are very lazy or can't find nettles in your area you can also decide di buy products made from nettle extract, they are therefore natural and environmentally friendly preparations. The fact remains that it is a pity to pay, not even a little, to have something that can be self-produced. When there is no time, however, it may be worth taking the shortcut of the ready-made extract and it is always better than spending it to buy toxic pesticides or fertilizers.
We find both the insecticide extract and the one for fertilizing purposes on the market.