From her first devil’s ivy in a macramé planter to thousands of plants both hardy and tender, Jean Starr is driven to put plants to the test in her corner of the world. She shares the results in magazines and her blog, petaltalk-jean.com.
 

 
 

Tropical Plants
by Jean Starr - posted 06/28/17

 

 

 

 

 

 

 

 

 

 

The plants in this garden all serve a purpose: food and medicine for man and beast (and insects).


“Go big or stay at home.” It’s become one of my springtime battle cries. Like me, my garden is becoming mature, (perhaps overgrown?), with plants becoming more relaxed, settled in and, some may even say, sloppy. It cries out for some eye-catching eye candy, something with a stately presence.

Luckily, Midwest garden centers finally are embracing the beauty of the tropics, so big plants are not hard to find. And I’m not talking about hardy shrubbery. Elephant ears, papyrus and tiger-striped cannas beckon and find rides in my cart along with the premium annuals and promising perennials.

‘Midori Sour’ Colocasia warrants its own container, as it has so much going for it, from its mottled chartreuse/blue-green leaves to its rose-colored spot where the stem joins the leaf.

What makes a plant “tropical?” Its origin is in the tropics, consistently hot and humid places throughout the world that serve up warm nights and steamy days, much like a Midwest summer.

Two plants that give you the best tropical bang for the buck are Colocasia and Alocasia, both of which have fallen into the collective category commonly called elephant ears. Both are in the Aroid family along with callas (Zantedeschia aethiopica) and caladiums.


Give them space
Mindy Walter, lead gardener at Como Park Zoo & Conservatory uses lots of large tropicals in the summer landscape. Mindy is responsible for all of the outside spaces, including the greater Como Park area and the zoo exhibits.

“We use a lot of palms and Alocasia, which is a steady winner for us because it makes a bold statement and takes the heat,” Walter said. “We can get them started early so they’re sizeable by the time we put them outside.” Staff at the gardens also plant bird of paradise, bananas (Musa spp., Ensete spp.), gingers (Zingiber spp.), cannas and Colocasia.

Some of the easiest to grow outdoors are birds of paradise, or Strelitzia. “You don’t have to fuss with them a whole lot,” she explained. “They only need grooming every couple of weeks.” Walter uses white bird of paradise in the zoo’s screened Butterfly Exhibit.

All of the overwintered tropical plants used in the outdoor exhibits are given a head start in the greenhouse so that they’re 3-4 feet high by late March. Walter says the conservatory soil is a custom mix containing peat, rock wool, and black dirt. “It works well in the pots for drainage,” she said. “We also use Osmocote, a slow-release fertilizer.”
 

Left: A gloriosa lily brings the look of the tropics to any garden. Middle: One of the best indoor-outdoor plants, ‘Amethyst Stars’ Pseuderanthemum laxiflorum is a tender shrub that is easy to start from cuttings and is a constant bloomer. Right: Vigna caracalla is an unusual and gorgeously fragrant flower that blooms on a fast-growing vine and likes full sun.


Tropicals in every garden
Barbara Weirich, designer/founder of Lake Cliff Gardens uses tropical plants in a big way. Each spring, she goes through the painstaking process of populating her private, 5-acre garden with tropical plants, most of which are kept in a greenhouse off-site.

“I have a lot of tropicals in every garden; even in the Asian collection where I have more shade,” Weirich said. “I find that those that tolerate more shade do better inside.”

She also starts around 800 seedlings each year for use in the gardens. Two of her started-from-seed standards are castor beans (Ricinus communis) and Hibiscus.


Barbara Weirich’s Lake Cliff Garden features loads of tropicals, such as castor bean, Dracaena and Eucomis. A few zinnias add spot color.
 

Although poisonous, castor bean provides one of the fastest-growing tropical-looking plants you can grow. Will Giles calls castor bean “a fantastic instant foliage plant for the exotic garden,” in his Encyclopedia of Exotic Plants for Temperate Climates.

If asked to name just one plant she couldn’t live without, one of the first on Weirich’s long list would be ‘Mahogany Splendor’ Hibiscus (H. acetosella ‘Mahogany Splendor’). “They can be cut as short as you want to keep them,” she said. “You almost never see a bloom, but you don’t need it.”


Brazilian fireworks is the common name for Porphyrocoma pholiana, which can do double-duty as a houseplant and still put on a show.


Easy to find
Two other favorites that are easy to find at garden centers are Acalypha and coleus (Plectranthus scutellarioides). Weirich likes to plant coleus beneath the banana plants. “They’re easy from seed and from cuttings. Now that there are so many types that take more sun, you can use them just about anywhere.”

With common names like copperleaf and jungle cloak, Acalypha species range from rangy to delicate. Acalypha hispida, often referred to as chenille plant, is known for its pink, cattail-like flowers that dangle from its pale green leaves. Acalypha wilkesiana ‘Tricolor’ is a colorful upright grower that can reach up to 5 feet in a summer, but can be pruned to size.

As for fueling the growth, Weirich uses various fertilizers at different intervals on the soil surface.


If you have a spot in the shade and a hankering for something besides Hosta, give Piper auratum a try.
 

Although using tropical plants in a temperate climate might seem like a new trend, it was really big in England during the Victorian Era (1837-1901). This period coincided with a time when the British empire was expanding into Africa, Asia, and India, where plant explorers were engaged in the discovery and collection of thousands of living treasures. It was the gentrified class that drove the discoveries. Business owners saw opportunities to cash in on the booming demand for plants fueled by the rising middle class and their newly-constructed communities.

In 1845, Britain repealed the glass tax, a method of taxing residents based on the number of windows built into their houses. Glass became cheaper to be manufactured and the Wardian case (devised to carry plants by ship from British colonies) was taken to the next level when glasshouses were built onto houses.

Even without a glass tax, most of us don’t have “glasshouses.” But with continuing discoveries and expanded hybridization, we can certainly acquire and grow as many tropical plants as we’d like.

 

A version of this article appeared in a July/August 2017 print edition of State-by-State Gardening.
Photography courtesy of Jean Starr.

 

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