When the kids finally tire of using that old wagon wheel as a spaceship, sailing ship or runaway train, moms can use it to add rustic charm to their gardens. Plants are grouped closely in between the spokes of a wagon wheels, lending formality to this rustic planter. As with a formal garden, planting should be based on a theme, such as edible plants, flowers of complementary colors or related plant families. Drought-tolerant plants will cope well with the dry conditions beneath the wheel and spokes.
Herb gardens are popular design solutions for wagon wheels. Perennial herbs, such as oregano (Origanum vulgare), can form the basis of the design, returning reliably year after year and providing a regular supply of fresh leaves and pretty, bee- and butterfly-attracting flowers. Annual herbs, such as cilantro (Coriandrum sativum), can fill other spaces between spokes, and allow the gardener the opportunity to experiment with new plants and new tastes in the kitchen. Oregano grows 12 to 18 inches tall and wide and is suitable for U.S. Department of Agriculture plant hardiness zones 4 through 8, and cilantro grows 18 to 24 inches tall and 12 to 18 inches wide.
Drought-tolerant, long-flowering perennials can fill a wagon wheel with blooms throughout the year and require little more than weekly watering. Sneezewort Gypsy White (Achillea ptarmica "Gipi Whit") produces prolific white double flowers from June through September and tolerates dry, rocky soil. Hardy in USDA zones 3 through 9, it grows 9 to 18 inches tall and 12 to 24 inches wide. Wild cranesbill "Variegatum" (Geranium macrorrhizum "Variegatum") blooms from May through June, bearing magenta flowers, and provides interest through the rest of the growing season with its grayish-green, cream-splashed leaves. Growing 12 to 18 inches tall and 12 to 24 inches wide, this perennial is hardy in USDA zones 3 through 8.
Grasses are sometimes under-appreciated for their ornamental value, but they offer a low-maintenance, attractive solution to wagon wheel landscape design. Variegated Japanese sedge (Carex morrowii "Aurea-variegata") has cream-striped green leaves that grow in clumps 12 inches tall and wide. Team it with black flowering fountain grass (Pennisetum alopecuroides "Moudry"), which grows 24 inches tall and 36 inches wide, for a striking contrast. Grow each plant in alternate spokes of the wheel, or add more grasses for greater variation in color and height. Both plants are hardy in USDA zones 5 through 9.
Tolerating full sun sites and providing long seasons of interest, succulents fill wagon wheel spokes with reliable color. Always Red hybrid aloe (Aloe x Always Red) provides blood-red hummingbird-attracting tubular blooms from spring through fall. Hardy in USDA zones 9 through 11, this succulent grows 12 to 14 inches tall and wide. "Lemon Coral" sedum (Sedum reflexum "Lemon Coral") grows 6 to 10 inches tall and up to 24 inches wide, and is hardy in USDA zones 7 through 11. It bears golden yellow, evergreen foliage, sometimes tinted reddish-orange in winter, and its small yellow star-shaped summer flowers are attractive to butterflies.