Really, though, don't beat yourself up if you can't let them roam, except maybe on the odd holiday.
Your garden is a world unto itself if you have one.
It's about valuing imagination and fantasy, about making these and a hint of magic a part of your lives.
We don't have a garden.
But we saw some friends who had one this past week, and just turned them all loose.
And that, well, what can you say? They had a blast.
Fantasy is chucking a blanket or sheet over the table and making it a fort, a house, a castle, a ship.
Playing hide and seek in the house on a cold winter evening.
Hunting for sea glass, pretending it may be leftover pirate fare or even treasure, maybe from a bottle of rum - Yohoho! And a bottle of rum!
It's about telling stories. Stories in song, even.
About visiting places at the weekend or in summer - castles, ruins, stone circles, places. Pointing out the wee isle in a loch. And the tale that goes with it.
Legend has its place here.
And I make sure mine are full of it.
Giving them a name. A name and what it means.
A place, a flower, a Gaelic translation of something.
What was her story?
It's about valuing things that, if you don't, might be lost.
Not just imagination. But, say, food production. British food production and farming.
Showing them where their food comes from.
Teach them traditional remedies and their native flora and fona. Like my friend, her daughter ran up to her with nettle stings and she told her to find docken leaves, where to go to find them, how did they look.
Even cities have farmer's markets.
Honour the seasons. Honour nature. Honour the heavens.
If they see you doing it, so will they.