Pussy Willows are one of our first signs of spring. Storing them is simple. You can either keep them out of water and they will stay as buds or you can put them in water and watch for new flower buds to cast off the shiny brown bud scales that surround the flower. When the flowers mature, you will see scores of yellow stamens emerge to cover each catkin. A tiny clump of pollen stands at each end. Wait even longer, and you may also see pale green, strappy leaves unfurl from the leaf buds. At this point, your willow stems will be in full spring growth and will need to be planted in soil outdoors to root for an extended experiment. The flexible stems can also be woven into a wreath or recycled in the compost pile.