Forget the fancy raised beds, central focal point, classic rotation and boring practical paths! Send the armillary sphere back to where it came from!
First, some of the de rigeur little projects for warm ups. Cucumbers in glass bottles. Pumpkins with our initials grown onto them. A sunflower house tall enough for ALL of us to have tea in. And for tea we'll have edible flowers in ice and candied violets.
Those are the definite projects, things you can read about in books like "Ready, Set, Grow! A Guide to Gardening With Children" by Suzanne Frutig Bales (ISBN 0-02-860399-0). That book also has a fab photo of a cake with live goldfish swimming around in it - and instructions so you can make one at home if you want to. Honestly - see page 79!
We're going to serenade the hummingbirds with trumpet flower bubbles, too, if I get my way this summer. That's an idea I found in Sharon Lovejoy's "Sunflower Houses: Garden Discoveries for Children of All Ages" (ISBN 0-934026-70-X) along with betting on hops, telling time with dandelion clocks, and of course we'll make hollyhock dolls and poppy maidens! We can also have violet wars and attack each other with flowers.
Pulling now from "50 Gardening Projects for Kids" by Clare Bradley (ISBN0-8317-7941-1), we'll borrow some of our neighbor's junked tires and paint them in bright colors and stack them up to make whimsical planters. (Who knows, maybe we could start a trend!) We have already learned by sad experience that steel belted tires can not be made into tulip-shaped planters.
And the following are strong possibilities, although they've come from many sources including my own imagination. Grow a pumpkin as big as a boat. Then carve it out and see if it floats. Actually make one of those pot people - or maybe a whole family. And plant stuff in their heads.
Turn an old commercial sized satellite dish into a planter for succulents. (If you have such a one, please email me. Thanks.) Use split rails to make a teepee frame and cover it with a tapestry of vines. Surround it with a moat. Recycle materials into a crazy paving path and tame it with a geometric pattern of river stones. Build a bridge for it to cross.
Turn the round stock tank pond into a living sundial. Grow some edible starchy tubers in a bale of straw. Train one of the random privets into a giant basket shape so the Easter Bunny will have a place to rest next year.