Gardeners' Dirt: Caladiums are shady summer superstars
By Beth Ellis - Victoria County Master GardenerEdited by Charla Borchers Leon
May 16, 2013 at 12:16 a.m.
Are you at your wit's end over a spot in your yard or on your porch where nothing will grow because it is too shady?
Are you about to give up and allocate that dank corner to the strange little garden gnome statue you found at last week's garage sale? If so, don't despair - I promise you are not doomed to eventually populate a portion of your property with salvaged statuary cast-offs.
Instead, you can make that dull space pop with vibrancy, courtesy of caladiums. Green leaves brightly patterned with white, pink and red will wake up that dark spot and convert it from a moldering gnome home to your very favorite place to hang out when relaxing in your yard.
Caladiums are another one of those lovely plant discoveries that coincided with the Victorian plant craze of the 1800s.
Amazon natives to European hybrids
These beauties are native to South and Central America with most coming from the Amazon River basin. The first specimens were discovered in 1773, with additional species collected about 80 years later in the 1850s.
Within a few years after the discovery of the additional plants, caladiums began to become available to European plant enthusiasts when Frenchmen Louis Van Houtte and Alfred Blue developed several hybrids.
Two originals available today
Happily for us heirloom gardeners, two of the original hybrids developed by Van Houtte and Blue are still commercially available today - "Triomphe de l'Exposition" and "Candidum."
Florida breeding program
Even though caladiums are New World plants, they were not really discovered by American gardeners until the 1893 World's Fair in Chicago, when German hybridizer Adolph Leitze reportedly exhibited more than 400 varieties to the public.
Public interest in the plants increased, and by 1910, famed Florida nurseryman Henry Nehrling began a successful breeding program. Several of Nehrling's varieties are still available commercially, including "Mrs. W.B. Hadlerman" and "Arno Nehrling" as well as others.
Fancy, strap leaf varieties
From the beginning, plant breeders capitalized on the characteristics of the original wild plants to develop two different varieties of caladiums - one with "fancy" heart shaped leaves (Caladium bicolor hybrids), and another with "lance" or "strap" shaped leaves (Caladium picturatum hybrids
The fancy leaf varieties produce taller plants with fewer but larger leaves, while the lance leaf varieties produce shorter plants with a greater number of smaller leaves. Nehrling concentrated primarily on fancy leafed caladiums, and by the 1930s fellow Floridian and hybridizer Theodore Mead concentrated on those with lance leaves.
As the 20th century progressed, various small growers continued to develop new varieties, and in the 1970s, the University of Florida developed an extensive breeding program with the goal of improving leaf color, disease and nematode resistance and cold tolerance.
Today, a festival is held each year in Lake Placid, Fla., to celebrate caladiums and introduce new varieties developed each year.
The first thing to consider when growing caladiums is that they are truly tropical plants - they love heat and detest the cold. For our area, that means planting them outdoors no earlier than around May 1. Here forward, you should be safe to plant them.
Most prefer shade to partial shade
As tropical rainforest plants, caladiums generally do best in shade or partial shade in the home landscape, although in recent years hybridizers have worked to produce more sun-tolerant varieties as well. In this neck of the woods, leaf colors will be most intense if the plants are not exposed to too much direct sun. Harsh sunlight will fade the colors and even produce "burn holes" in the leaves.
Plant with organic matter in moist soil
As to soil and water, caladiums prefer lots of organic matter and moist soil, but they dislike wet feet. Plant corms about 2 inches deep with the bumpy side up - the bumps are the eyes from which leaves sprout. If you can't tell which side is which, just plant the corm sideways - it'll grow.
Make sure corms are planted in well-drained soil to prevent rotting. Water regularly enough to prevent wilting, and feed them once or twice a month with a balanced fertilizer.
Disease and pest resistant if not too wet
Disease and insects are not much of a problem for caladiums. Root rot can be an issue if the corms are consistently too wet - to help avoid it, treat plants with a fungicide a couple of weeks after planting. If rot problems continue, consider adding amendments to improve drainage, or adjust your schedule to avoid overwatering. If insects such as aphids appear, use a general purpose insecticide to eliminate them.
There's more to come
Next week's article will remember those who have gave their lives for our country with red, white and blue garden pride, but the following week, there will be more on caladiums.
We'll look at selecting the right varieties for specific jobs, preparation methods for getting the best results from corms, and over-wintering options.
The Gardeners' Dirt is written by members of the Victoria County Master Gardener Association, an educational outreach of Texas AgriLife Extension - Victoria County. Mail your questions in care of the Advocate, P.O. Box 1518, Victoria, TX 77901; or email@example.com, or comment on this column at VictoriaAdvocate.com.