The garden is too dangerous for the kids because there are a lot of sharp things around. :) I didn't build it with kids in mind, so for example all the wire fencing is just cut with no ends. We'll get out there with them in a few years. My daughter helps with the front yard sometimes.
Its all rusty barbed wire fence by us, so rationally it doesn't make a difference, wouldn't want my kids injuring themselves on something like that in the garden though.