Trees need to grow

Well, its was bit to easy, to plant full grown trees. So, Poor Patric now has to wait some time for his trees to grow. At the moment, it takes about 15 minutes, or to be exact 950 seconds, to grow a tree to its full size . Well, for now it seems a long time, but my guess is, it will be longer in the finished version. Anyway, in my experience, time flies when you play a game...

And feel free to share your experience and suggestions in the comments.