Fern gully.

I used the hapa-zome method of beating color into cloth using a fern frond on silk. Hapa-zome is literally "leaf-dye" in Japanese, according to India Flint, author of Eco Colour: Botanical Dyes for Beautiful Textiles. 

It's one of the easiest ways to transfer the color and pattern of plant material onto fabric. Be patient, as hammering too hard will no doubt create holes.
Hapa-zome Technique by India Flint

Materials

• Leaves
• A small hammer or mallet
• Some cloth of fairly dense weave (not too flimsy)
• Thin cardboard or thick paper (such as cardstock)

1. Place the paper or cardstock on your work surface (such as a sturdy bench or uncarpeted floor) and place your cloth on the paper.
2. Arrange your leaves on the fabric. You could make a discrete array of leaves, overlap them slightly, or chop and scatter them over the surface of the fabric.
3. Fold over the cloth and place another piece of paper on top of the cloth and apply the hammer. It can take a little practice to get the hammer strokes just right, so experiment.
4. Remove the plant material and let the cloth dry thoroughly. Then press with a steam iron or heat press to set the color. (Despite this, the color will probably fade over time. Consider it part of the natural process.)
Eco Colour is filled with techniques for using plant materials to print and dye with in every season. Along with ideas for how to use the resulting fabrics. India suggests, for example, that you use the hapa-zome method to decorate t-shirts.
The fern may fade and change with time... but, so will I!