Copper planters are decorative metal containers which don’t rust. Untreated copper bottles do tarnish with a greenish cast, however they don’t break or crack. Many shapes and sizes are available, including exceptionally detailed and textured plant pots. Copper planters often discourage insects such as slugs and snails and run heat so that the soil heats up in direct sunlight. These planters are useful for growing plants inside and outside.
Too much copper in the soil could impede plants’ uptake of nutrients, which can stunt development. Copper in the soil also kills the tips of small feeder roots. This rarely happens in copper planters since the copper is fixed in the form of the container and only tiny amounts can leech into the soil. If toxicity is an issue, either line the planter or put your plant in a container that is smaller that the fits into the copper container.
Ornamental grasses grow well in copper planters, supplying a vertical, classic look. One arching grass is that the “Fireworks” fountain grass (Pennisetum setaceum “Fireworks”), growing 36 inches tall spreading 24 inches wide in U.S. Department of Agriculture plant hardiness zones 9 and 10. The grass blades are striped with white, green, burgundy and warm pink colors, and purple tassels appear in the summer and function well as cut flowers. Ruby grass (Melinus nerviglumis) forms clumps of blue-green upright blades using 8- to 12-inch-long purplish-pink plumes throughout the summer in USDA zones 8 through 11.
Perennial flowers endure for years in copper bottles without having to be reseeded every year. One example is that the “Minarette” dwarf lupine (Lupinus polyphyllus “Minarette”), that produces showy, 1 1/2-foot-tall flower spikes in the summer over a mound of green leaves. This perennial flower is available in blue, red, yellow, pink and white in USDA plant hardiness zones 4 through 9. “Sunny Elena” African daisies (Osteospermum “Sunny Elena”), in USDA zones 9 through 11, produce rich purple blossoms using unusual spoon-shaped petals with evergreen leaves. The 6- through 8-inch-tall flowers appear from spring through autumn.
Based on the magnitude of the copper planters, small shrubs grow well in such decorative containers. The shrub-like yucca “Color Guard” Adam’s needle (Yucca filamentosa “Color Guard”) provides stunning architectural forms using green- plus yellow-striped, sword-shaped leaves reaching 2 feet tall with white, bell-shaped summer blooms on top of a 6-foot-tall stalk in USDA zones 5 through 10. The yellow coloration turns rose-colored during cold weather. “Dusky Bells” Australian fuchsia (Correa “Dusky Bells”) grows best in USDA zones 9 and 10, reaching 1 to 3 feet tall with pink, tubular-shaped flowers appearing from autumn until spring using deep green, citrus-scented evergreen leaves. This tree attracts hummingbirds to the container.