This is a good time of year to keep your eyes in the cracks of buildings and edges of lanscaping searching for sprouted tree-seeds. Often times they are actually pretty obviously next to the parent tree. If you save out these seedlings this time of year and pot them up or replant them, after several years of care and regular watering you will have a lovely tree that you can gift to someone who has managed to get property but is strapped for landscaping.
I always gather japanese maple seedlings from near the library where Ilive, and my own yard is studded with lovely smallish trees in large containers resulting from this practice.
The Bamboo is starting to throw up culms this time of year as well. It is a good time to keep aneye out for stray runners that show up on sidewalks and outside of fences.