Children and their gardens

I think the key word in your title is "their"
their gardens, their choice what they do in them.

Both my DDs have smallish, easily maintained gardens, as both they and their DH’s work.
I’ve a big garden and they love to be outside when they’re here. I think it’s just a change for them with different toys, a shed, sandpit and room to kick a football around. Garden picnics are a high point, both here and at home.
However, they do take full advantage of nearby parks and areas where they can run around and feed ducks and swans, etc.

Whether he is at home or at ours, our GS is out in the garden most of the time. He's never happier than when he is outdoors, but he loves playing in the garden, especially practising his football skills.