My oldest started a fairy garden last week with some garden statues and rocks. I added a bunch more stuff last week that I found around the house, like painted sticks and leaves, a cinnamon broom from last fall, acorn caps, painted flower pots and dried lavender. She got busy arranging the garden. Its pretty fun to walk by and see it change everyday as she moves things around.
My son of course also wanted his own play garden, so I quickly gathered a few dinosaurs, sea shells, rocks and dried lavender. They both spent a good hour playing in these little gardens. Many of my plants are just starting to come up so they are perfect for play gardens. But you could also use wheelbarrows, old wagons, saucers for potted plants, orphan drawers, wine boxes/barrels or just a spot in the backyard.
You can also make a garden for any toy... trucks, farm animals, my little ponies, littlest pet shops, etc.
Some supplies to make your garden fun:
small plants - succulents are great so is moss.
small dishes - that can hold pebbles, rocks, water
Rocks and gravel
Sticks, acorns, pine cones, pine needles, tree nuts/seeds (walnuts, eucalyptus nuts, etc) leaves, flowers, sea shells.
Pots, jars, coir pots
Just looking around your garden or home you are sure to come up with some fun items for your next play garden. K