So, I asked my brother while he was sitting at the writing desk and I had my morning coffee.
We looked it up, assured to get the right translation and talk about the same plant. Allium Ursinum.
My brother studied agriculture sciences, grows vegetables since decades and since more than 20 years professionally, also on the market very rare herbs, weeds in half culture etc. And he is a passionate hiker on top and sees the weeds in the woods.
We can surely call him a very good specialist for this case.
Early winter wouldn't have been totally nonsense, compared to displacing wild garlic now, what would be wrong, but nevertheless I was wrong.
You should do it like this:
You watch the wild garlic in late spring.
When the wood becomes green the wild garlic doesn't get enough light anymore and pulls in. He disappears into his onion.
Here in Berlin it's around first of June, but could happen a few weeks earlier or later in Britain, you simply need to watch it.
Exactly when it has disappeared you can dig it out and displace it in a similar habitat: He needs moist forest, loves to grow near streams and can also be found under bushes.
You theoretically could store the onions correctly until September and plant it then, but as an amateur you plant it immediately after you digged it out.
Here it grows like weed but, anyway, only in the right habitat, and anyway it is illegal here to displace it and so you should dig out just a few of them to avoid making a real damage.
Around Berlin they grow already where they can do it.
And we assume, but didn't look it up, that it is also illegal to displace wild plants in Britain.