I used leaves from a tree of my parents' neighbours, who happily gave them to me. I modified the dye with a bit of iron after the dyebath. (much less for silk & wool, though)
this last photo shows a silk scarf (with hand rolled hem),available for purchase in the shop.
The tie-dyed pieces of cotton you can see on the photos will be pouches for wrapping naturally dyed items purchased from the shop. You can see the first ones I had made here, and some others here too.
If you want to see more details, click the photos, they will take you to Flickr.