1. He's going to plant some new flowers
2. Firstly, the person should take care of his garden. For example, don't forget to water plants
3. Yes, he enjoy his hobby, because, in the picture, we could see how attentively he's taking care of the plants
4. Honestly, I am not fond of gardening, because for me it's kind of boring. I prefer "extreme" hobby such as water rafting