During my summer of natural dyeing I have found many plants from which you can get similar kinds of shades of yellow and green. Usually white yarns turn to yellow and grey yarns to green. I have collected some of them in here. All the yarns displayed have been mordanted previously with alum (read about it here.) I used the same technique as I did when dyeing with lupine (read about it here.)
I collected the cow parsley early in the summer when they were blooming. The result was not the most intensive one but still pretty.
Both meadowsweet (on the left) and fireweed (on the right) were collected early in June when they were not yet blooming.