By popular request, I'll be explaining more about my gardening in the next few days, once I have time to organize my info. In the meantime, let me just say that I'm addicted to the Palm OS game Plant Tycoon. It is like Sim City for gardening. You manage a nursery, and you get to create new hybrid plants through cross-pollination.
The game works in "real time" whether your Palm is on or off. If you plant a seed, it will take several hours of real time for it to grow. You just have to check back later. It is still much quicker than real gardening, but it is slower than almost any other Palm game. I highly recommend this game.