As I expected I got bored of this project and of the weekly update. Even because my "tree" was NOT a tree but just some kind of weed. However in the same pot now there is a friend that seems really a tree!You can see it in the right corner or in this close up pic:
It is summertime and my vase is 24h a day outside the balcony but it recive direct sunlight just until 10 am, so there is not a risk of burn the leaves. i'm also adding some coffee grounds sometimes to make the soil more nutrient.