So, after a little research, I found out that this idea is very new, started a few years ago in US. There is a group in London, called Knit the City who are involved in this type of art. It has many names, yarn bombing, yarn graffiti, kniffiti.
This yarn bombing was supporting International Festival of Business and Baltic Creative. The trees received their cozies late June and I’m glad they are still on. My husband and I went to a trade show organized at IFB, we’ve participated at some seminars. The display on Park Lane was made by Karen McFarlane and the crochet group Happy Hookers.