Breeding Groots

In the movie Guardians of the Galaxy, a walking, talking tree named Groot became a beloved character. He certainly belongs to a unique species, as evidenced by the Collector's fascination with him. The Collector boasts one of the largest collections of fauna in the Universe, and desperately wanted to add Groot to his collection. Obviously there aren't too many of these creatures out there. They are called Flora Colossus from the Planet X and are raised in nurseries by a caretaker species. Groot had been exiled from his home planet as a youth, left to wander the galaxy.

We don't currently know how his species breeds or reproduces, but we do know that when he was smashed to pieces at the end of the movie, Rocket picks up a twig from the remains, planted it in a bowl, and baby Groot was born. My first question, why didn't Rocket pick up several twigs and plant a whole bunch of Groots? If it's that easy to grow more of them, why is the species so rare? Couldn't you harvest several twigs from a live Groot, then plant them to grow an army of Groots?

We would expect this species to reproduce like other trees, where one gender has seeds and are fertilized with pollen from the other. But due to how rare the Groot species is in the galaxy, it's unlikely that many new saplings are born from seedlings outside the home planet. Taking a "cutting" and planting it in soil is not classic reproduction, but cloning. If anyone did want to create a Groot army, they would probably need to clone several individuals from only a single source parent instead of using the natural fertilization process. There is a possibility that some of your clones may have genetic defects, depending on the complexity of the internal organs. We don't even know if there are any females of the species still alive, they could all be extinct.

Let's say you wanted an army of Groots, or even just a single pet Groot, but were not able to clone him directly, it would be necessary to collect some of his pollen (which would be found in those little yellow flowers that grow on him). This would probably be easier than cutting off a piece of him. Send a remote control bee to land on one of his flowers, then use that pollen to fertilize females of either the same or the closest relative species you can find. Hopefully in a few years, baby Groots will grow from the ground. And once you've got one, you can then create many, possibly even a clone army.