Jumping from a perfectly good airplane... seems crazy to me, but my brother, my father, and my grandfather do it together every 10 years (next year grandpa will be 90 and still wants to go!)
I love Looney Tunes for physics. A couple years ago we even did an exam all based on Looney Tunes cartoons (watched the cartoon clips, analyzed the physics to determine what was right / wrong, etc.). Poor Coyote. http://www4.ncsu.edu/~gsparson/Physics/
Great question. When I worked at Samsung down in Texas one of my technicians played darts professionally as a hobby (and I believe was state champion). We went out one night and he was just amazing. He could put that dart just about anywhere he wanted EVERY DARN TIME. And as I recall, the darts had pretty high velocity.
Hmmm... I'm confused as to why you might say "while gravity was not acting on the plants." Why wouldn't gravity be acting on the plants when they are on the ISS?
Same thing happened to me recently. Missus F. had her copy on the dashboard as I accelerated out of a parking lot onto a faster road. Her coffee got "left behind," resulting in the "evil eye!"