Here is a neat idea that may help re-grow the trees from which they came from. The Sprout Pencils seem like any ordinary pencil you may have come across only that when they reach the stub, they can be actually replanted to grow new plants.
Apparently the pencils come with seeds at the top. People who get them can choose from various seeds that include herbs, vegetables and flower seeds. Reportedly, the seeds sprout a week after being planted.
The seed capsules are water activated so no need to chew or resort to anything once it reaches its useful life. The pencil stub can be thrown out or used as a labeled planting marker.