I've been ecodyeing a bit lately. With eucalypt and poppy. I used the steaming method with some vinegar in the water and a piece of metal scouring pad in the steam basket. At first I tried it with pieces of cotton and flannel but it turned out that silk worked the best.
Here you see some bundles with the eucalypt leaves after they've been cooked for an hour.
And this is one of the silks after it has been left to dry (in the bundle) for 24 hours. I find it amazing that those greyish leaves can make such a bright orange colour. (The poppies give a very dark purple/aubergine colour.)