Gardeners in Missouri are always trying to find cultivars and unique plants to light up a display bed with color and texture. For some, it is a border of annual flowers, for others unique foliage perennials. In the never ending search for just the right plant to add color and interest to our flower gardens, tropical plants are becoming more popular; thriving in the heat and humidity synonymous with "summer in Missouri."
As a gardener one of my favorite garden center piece specimen plants, is Alocasia odora, what is commonly referred to as an up-right elephant ear. If given the right spot with plenty of moisture, a good layer of mulch, and nutrients, this monstrous tropical plant can grow up to 6 feet tall in a single summer season. Its deep green heart shape leaves stand tall above the petioles (leave stems), and can reach up to 2 feet in diameter.
Alocasia's prefer moist, well drained conditions, in bright shade. Although they can tolerate full sun conditions, the more sun they receive the greater the amount of water required. Because of their height and size, and straight lush growth, they make great focal points in a part sun garden; without excessively shading the low growing plants below. In my garden, I have these Alocasias planted amongst a bed of heuchera, growing under a high canopy of oaks.
Prior to planting both Alocasias and Colocasias, it is recommended to incorporate about 2 lbs. per 100 square feet of an all-purpose slow release fertilizer into the bed.
Colocasia esculenta are what we typically think of the common "elephant ear" tropical bulb, commonly called "Taro." Producing huge drooping heart shape leaves, on tall 4 foot high petioles, this tropical bulb makes a great foliage backdrop to any open woodland garden, if given plenty of moisture and nutrients. Because of their drooping nature, it is important to either give them plenty of space, or hold them up with a few stakes and a line of twine. Although they take fun sun conditions, like Alocasias, I prefer to give them part sun conditions, to limit water requirements.
Both Alocasia and Colocasias come in some fascinating plant species and cultivars. Colocasia esculenta 'Black magic,' is a commonly sold dark purple leaved version which adds a pop of color to garden bed. Colocasia esculenta 'Illustrious' is a variety by Proven Winners which sports purplish leaves with light green venation.
These tropical bulbs are heavy feeders, and every 4 weeks fertilizer should be applied during the summer growing season.
Overwintering the bulbs:
In the winter, Alocasias and Colocasias should be dug right after the first light frost. After cleaning off the bulbs with water, I allow them to dry. The Missouri Botanical Garden recommends packing the bulbs in peat moss or wood shavings. They should be stored at temperatures between 40-50 degrees F. for the winter. To improve drainage for next season's tropical plantings, incorporate 3 inches of compost into the bed this fall. Bulbs should be planted back outside around the 15th of May, 2-3 inches below the soil's surface.
Page 2 of 2 - Last year I packed my Colocasia bulbs in a box full of dry shredded oak leaves, wrapped in a double layer of Agribon row cover fabric. This box I placed underneath the house in a slightly below ground concrete crawl space. With the mild winter, the bulbs overwintered beautifully. There are many ways to accomplish this over wintering process, but if done properly, the plants can spread, and become quite enormous over the years.
Opportunity for Avid Gardeners interested in sharing their knowledge of gardening with others:
For those who enjoy gardening and would like to share their knowledge with others, there is a great opportunity this fall to join the Missouri Master Gardeners, a not-for profit state wide University of Missouri Extension supported program to train gardeners in horticulture so that they can in turn teach others in their community.
A new Master Gardener Core Course training session, sponsored by the Phelps and Pulaski County Master Gardeners, will be held at the Waynesville, MO courthouse on Thursday evenings from August 22nd though October 24th. For more information, please contact the Pulaski County Extension office at (573) 774-6177, or go to the Phelps County Extension Center website at http://extension.missouri.edu/phelps .