I'd like to get more into gardening, what's the best way to learn about theory online?
user
There are lots of books you can find in your local library or on Amazon, and some videos you can find online.  I'm also happy to recommend a particular book I've used and enjoyed myself.
assistant
I'm particularly interested in designing a garden from scratch. Are there some good resources for garden design and planning?
user
Yes!  I'm happy to help you learn more about garden design, but you'll need to ask a more specific question.
assistant
Well, I'd like to design a small garden for a garden in France. It's a temperate climate, are there some good recommendations? As in, which flowers and plants to plant?
user
You might want to use a combination of temperate and tropical plants.  A good place to start might be to research local flowers, and then choose some that would work well together.  You can also take a look at some plants that are already native to France.  There are plenty of resources for this type of information online.
assistant
I'd like to get more into gardening, what's the best way to learn about theory online?
user
There are lots of books you can find in your local library or on Amazon, and some videos you can find online.  I'm also happy to recommend a particular book I've used and enjoyed myself.
assistant
I'm particularly interested in designing a garden from scratch. Are there some good resources for garden design and planning?
user
Yes!  I'm happy to help you learn more about garden design, but you'll need to ask a more specific question.
assistant
Well, I'd like to design a small garden for a garden in France. It's a temperate climate, are there some good recommendations? As in, which flowers and plants to plant?
user
Yes, there are many good books on this subject.  Here's one that I really like, it's also a set of short stories about a woman who grows a garden in France:

Labyrinth  by Kate Mosse
assistant
I'd like to get more into gardening, what's the best way to learn about theory online?