My head started swirling with all the areas of interests, but here's my 1/2 cents.
Find a major that gives you flexibility to take what you're interested in but also a smattering of other stuff. The fewer requirements frequently the more flexibility to design your own curriculum. I started out as a bio-major but it was too restrictive b/c it was also pre-med and I wanted to take art, and other stuff. I ended up as a Animal Science major but now grow plants for a living!
Look into tissue culture, right up your alley and it's as much an art as a science in some ways. Also look into Plant and soil Science could give you some good fundamentals to build on. Also start looking into plant breeding (genetics can get pretty esoteric pretty quick). Some plants take years to develop and to get new characteristics, you're young start now and you'll have stuff that people will kill for by the time your in your late 20's!