Tropicals for the Container Garden

Andrew Bunting

On a recent trip to the Smithsonian Gardens, I was reminded of one of my favorite tropical plants, which is in cultivation, but deserves greater use for summer interest in ornamental containers. Mussaenda is a tropical shrub that’s characterized by large colorful bracts of pink, red and white. Mussaenda frondosa has large white bracts with tiny orange flowers that are pollinator attracters. All mussaendas thrive in full sun. Mussaenda Queen Sirkit has clusters of soft pink bracts, while Mussaenda philippica Don Aurora has large clusters of white bract

Another great specimen for a summer container is Tibouchina grandifolia, a South American native with large textural leaves that have a soft, velvet-like texture. The flowers are quarter-sized featuring a vibrant violet-purple that occur at the tips of the branches. Customers should grow it in full sun to get the best growth and flowering. Hardy to USDA Zone 8 or above, this can be grown as a permanent container plant in more southern climates. In temperate climates, it takes some time for Tibouchina to grow in stature; therefore, if possible, overwinter on a cool sunny porch, greenhouse, etc. Each year the size will increase, as will the production of flowers. Another excellent relative is Tibouchina urvilleana, which has narrower leaves, small flowers and a more rounded habit.

Showstopping Elephant Ears

The elephant ear has gone through an amazing renaissance. For many years, the large green leaves of the straight species Colocasia esculenta was the only available option. But thanks in large part to the work in particular of Tony Avent at Plant Delights Nursery, there has been a resurgence in the popularity of this tropical genus, which provides bold tropical leaves for great summer effect. Colocasia Royal Hawaiian Maui Gold has leaves up to 4-ft. long that are chartreuse. It’s a great elephant ear to grow in sun or can be used to brighten a shady corner.

One of my favorite groups are those with dark leaves. One of the older cultivars is Illustris, which is medium sized and has green leaves with luxuriant black veins. Colocasia Black Magic (syn. Jet Black Wonder) makes a bold impact in the garden with clumps of large black leaves that can reach 4- to 6-ft. tall.  It’s hardy to USDA Zone 7B or higher.

Black Beauty is similar in stature to Black Magic, but has black leaves with green veins. Coal Miner has a larger stature then Illustris, reaching 4 to 5 ft. at maturity and also has black leaves with green veins. Colocasia esculenta Royal Hawaiian Diamond Head makes an amazing statement in a container with large glossy black leaves.

Including Cannas

Ever since I started gardening, I’ve been a fan of cannas. I love their tropical effect in the summer garden, and with new cultivars and breeding over the last few decades, there are many sizes to choose from. Many have beautiful striated foliage and the colors range from yellow to orange to red and a sea of pinks. An entire article could be dedicated to cannas, but these are a few of my favorites: Canna Tropicanna (syn. Phaison) is an amazing canna. The strap-like leaves can reach up to 7-ft. tall. The leaves are striated with burgundy, pink, orange and green. Vivid orange flowers are born in profusion atop the foliage. Like all tropical foliage plants, cannas will benefit from a slow-release fertilizer in the spring and then regular fertilization with a liquid fertilizer high in nitrogen.

A more diminutive version of Tropicanna is B. Marley, which will only reach 3.5 ft. A favorite that I use most every year is Canna Bengal Tiger (syn. Pretoria), which also has orange flowers, but has striated green and yellow leaves. Bengal Tiger can be effectively grown in sun or shade and can also be used as an aquatic in a pond.

Red Stripe is a relatively new introduction that reaches 5-ft. tall and has foliage similar to Bengal Tiger, but has striking pink-red flowers. Both Canna Orange Punch and Lemon Punch are cannas that only reach about 4-ft. tall and have bright orange and lemon-yellow flowers, respectively.

Another great series that has a compact habit is Canna Cannova. There are many selections, including Cannova Rose, Cannova Yellow, and my favorite, Cannova Bronze Orange, which has very dark bronze-black foliage that beautifully contrasts with the bright orange flowers.

And two cannas that have stood the test of time and are still excellent today are Australia (with shiny black-red foliage and bright red flowers) and Wyoming (with burgundy-green foliage and orange flowers).

All of these tropicals will grow very fast with ample amounts of water and fertilizer, and thrive in warm and humid summer-like conditions. Regular grooming of old leaves and removing flowers once they’re passed will make them all stunning additions for use in containers. GP

Andrew Bunting is the Vice President of Public Horticulture for the Pennsylvania Horticultural Society, which uses horticulture to advance the health and well-being of the Greater Philadelphia region. Andrew has decades of horticultural experience, ranging from his tenures at public gardens in the U. S. and abroad, as well as a published author, gardening expert and sought-after presenter. To learn more about PHS or to become a member and support greening initiatives in over 250 neighborhoods, visit PHSonline.org.