Aside from gardening, of course.
Habitat restoration
That's basically what my garden is, does it count? I'm constantly thinking about ways to continuously improve the habitat I've created.
Camping & Hiking
Absolutely love camping, mostly because it means hours and hours of hiking in nature, as well as canoeing, biking, and submerging myself in nature. Tons of fun!
Photography
My #1 hobby, mainly because I can easily combine it with my previously mentioned hobbies. I love being able to show people photos of insects, animals, plants, and habitat that need to be recognized and protected. I hope the more people understand how quickly we're losing so many unique things, the more people will want to do something about it.
Gaming
This was a bigger hobby for me when I was younger. Now it's just a way to pass time in Winter or when it's rainy. I have a very small selection of games that I play. I like games that include exploration. I also love racing games.
Music
I listen to music all the time, so I consider that a hobby. I'm listening to it right now. I combine it with everything I do. I listen to just about every genre. A lot of people are stuck on specific genres, but I judge a song based on the song itself, not who it's by or what genre it is. My itunes library includes artists like Eminem, Tupac, Brooks & Dunn, Metallica, The Scorpions, Kid Cudi, Carrie Underwood, Bob Seger, Pink Floyd, Phillip Phillips, The Beatles, Whole Wheat Bread, Garth Brooks, AC/DC, Miley Cyrus, and literally hundreds of other artists and bands. I even have some of The Lion King score by Hans Zimmer. Oh, and I used to produce music, too, but that's a story for another day.