Yes, I'm sure we've all had an experience from time to time with the plants in the picture.
The burning tingle of nettles is something we eventually get used to if we work in a garden or do landscaping. These are some nice specimens by my pond.
There are many species of nettles, these are European stinging nettles. I seem to remember the nettles in Northwestern Ohio as having rounder leaves, but the same sting.
The sting can be extremely dangerous in some tropical and Australian species of Urtica. It is caused by a mix of irritants and toxins delivered by hairs, like tiny hypodermics.
Here in the Dordogne, old people claim that nettles or ortie can relief the pain of arthritis and you can develop a resistance to them over time. I believe this, as my personal discomfort from touching them seems to be diminshing.
They spread by seeds and develop very deep and intricate root systems. The roots are yellow and very hard to eradicate if you've ever tried, you know what I mean.
But, what seems to be a curse is actually a blessing.
Nettles are one of the most useful garden plants. They can eliminate the need for commercial fertilizers and insecticides. This is ancient knowlege, but now, it is being systematically proven.
A horiculturalist, Jean-Francois Lyphout near here has been championing the use of Ortie Slurry for years and one of the major local strawberry farmers has turned his entire operation into an organic hydroponic system with raised beds and uses ortie as his major fertilizer. This was a big gamble, but in the last few years, it has really paid off.
The strawberry farmer, Didier Clerjoux is also using Comfrey slurry and a Fern slurry.
The Nettles should be cut before they go to flower and broken and crushed. The crushed orties are steeped in water. The water turns deep green from the chlorophyl. Ideally, the water should be filtered and kept in dark sealed bottle sfor long tuerm use.
It is pretty powerful stuff and can burn sensitive plants, but I have never had this experience. When the slurry is kept in a bucket too long, it starts to really stink, so it is important to filter it, the stink doesn't develop if it is filtered. Do not store the finished ortie liquid in metal containers! I use plastic liter water bottles and keep them in the barn in the dark.
This year, for the first time, I put crushed ortie in the holes I planted my tomato plants in. So far, the plants look great, but it's very early in the season for me to tell you jhow much better they are.
The slurry is rich in nitrogen and can be used to occasionally water plants and when it is sprayed on, it makes the plants resistant to diseases and insects like mites and aphids.
In Europe, the nettle is traditionally a food source. The sting disappears after cooking.
The ortie is high in protein and very high in vitamin C and Phosphorus.
We make ortie soup occasionally by boiling the ortie leaves in a little chicken broth, then making a puree in the processor and adding a little cream. When made this way, the soup tastes a like advocado.
We have been using ortie for years on flowing plants, but this is the first time I have really started to use it in our vegetable garden.
Recently, I aquired some comfrey plants which are another very powerful "green manure" source as well as having many other medicinal uses. They are very attractive, and they don't have a sting...I used to wage a war against the Nettles on my property, of course all I have to do is go to road side and their are fields of them, all for me and my raspberries!