All plants are not created equal in the eyes of children. Although they don't differentiate when it comes to flowers over vegetables, annuals or perennials (in fact they're likely to plant them side by side), kids have their hands-down favorites.
Kids like extremes: huge flowers, like the classic sunflower, and small vegetables, like cherry or tiny grapelike tomatoes. If you have room, try 'Atlantic Giant' pumpkins; if you don't, try bush cucumbers and pick them at cornichon-size for tiny pickles. Try plants that come in surprising colors, such as purple carrots, striped beets, rainbow chard, and 'Easter egg' radishes.
"Performing plants" always tops our list. We grow Mimosa pudica sensitive ferns because they close to the touch; snapdragons to make the flowers "talk"; and bleeding hearts, whose flowers reveal treasures when dissected. We've also tried Chinese lanterns (invasive), balloon flowers, love-in-a-puff, and money plants (Lunaria).
Textured plants are irresistible. If your conditions are right for them, include the fuzzy woolly thyme and lambs' ears, the prickly coneflower and strawflowers, and the delicate maidenhair fern and columbine.
Fragrant plants transport the imagination. If you grow them now, your child will always remember the scents of heliotrope, mignonette, roses, peonies, and lilacs. If you show them which plants to rub between their fingers, they'll never forget lavender, pineapple mint, lemon balm, rosemary, basil, and scented geraniums.
Butterflies are beloved in the garden. Everyone says plant monarda, butterfly weed, and salvia to attract them. I say plant parsley, dill, milkweed, thistles, and knapweed--wild plants are the diet butterflies expect.
Night bloomers fill summer evenings with magic. My children will never forget the nights we went out with flashlights and saw the sphinx moths zooming among the nicotiana and moonflowers. Four o'clock strikes, and evening primrose open, as their name promises.
Positively pickable plants also get the thumbs up from kids. While mom's landscape may be off-limits for bouquet gathering, children should have free reign over certain cutting gardens. Cosmos, snapdragon, salvia, zinnia, coleus, and celosia are just a few that produce more vigorously if picked. At our house, kids know that the dandelions, violets, hawkweed, and other surprises growing in the lawn are free for all.
And besides all these high-performance plants, parents shouldn't overlook those stalwarts of the nursery trade. Common annuals or tender perennials are common because they bloom reliably all summer long. That's what kids want, so include these hard-workers in the mix:
For full sun: geraniums, morning glories, marigolds, nasturtiums, petunias, salvia, snapdragons, strawflowers, and sunflowers.
For semi-shade: begonias, forget-me-nots, impatiens, Johnny-jump-ups, and pansies.
For deeper shade, flowering annuals are hard to come by: abutilon, variegated ivies, sensitive plants, and ferns. Don't overlook bulbs and corms--especially the tiny ones such as daffodils and irises. Grape hyacinth, crocus, and snowdrops are naturally small.