The simple secret to a successful, eye-catching monochromatic container garden: a mix of foliage shapes, sizes, and textures.
Wispy stems of 'Fireworks' fountaingrass and broad variegated croton leaves provide height and structure. Wide, ruffled heuchera fills the base; the delicate leaves and deeply colored stems of bloodleaf (Iresine herbstii) spill over the edge. Assorted Swiss chard has the spotlight in its own pot. (Clay pebbles—sold as hydroponic grow medium—camouflage soil around the leggy stems.)
The Color Purple
Not much is more dramatic than a combination of the darkest black-purple plants in pots of the same hue.
Tall Persian shield and low-growing heuchera combine for a mass of solid color. Bonus: Heuchera looks good all season with deadheading. Dainty white flowers peek around the shamrock leaves of deep purple oxalis. Add spice to the grouping with a pot of 'Purple Flash' peppers.
White and pale green foliage blend to a silver finish, ideal for adding contrast to dark backgrounds.
'Sky Rocket' fountaingrass and its pink-tinged cream plumes add texture. 'Blue Star' juniper will survive winter in a frostproof container. Culinary sage and large-leaf ornamental silver sage (Salvia argentea) soften edges with their velvety leaves.
Yellow-green plants stand out against darker shades of green and brighten shady parts of the garden.
The dwarf evergreen lemon cypress scents the air when touched. Add more energy to the mix by pulling from the opposite side of the color wheel, like magenta in the small leaves of 'Burgundy Wedding Train' coleus. 'Carolyn's Gold' miniature hosta is a solid pick for the base. 'All Gold' Japanese forest grass spills over the edge. Add height wherever you like with a standard topiary of 'Gay's Delight' coleus.
Shades of purple and silver merge for a blue effect.
Sturdy shoots of 'Blue Arrows' rush stand tall in a planter, creating subtle privacy. Ornamental kale looks like flowers on steroids. Bonus: They hold their own all season. 'Silver Falls' dichondra drapes for softness. The intense silver foliage of 'Icicles' licorice plant looks powdery white.