These exciting caladium varieties were bred to withstand the heat and sun. They have performed extremely well in university trials and are suited for pots, baskets and landscape plantings.
Strap-leaf caladium varieties as a group are generally more sun tolerant than many of the fancy-leaf varieties. Nevertheless, certain strap varieties are more sun tolerant than others. In 2000, Classic Caladiums began a clonal selection and tissue culture program to reintroduce rejuvenated selected commercial caladium varieties. Similarly the company expanded its breeding program to develop and introduce new genetics into the caladium line. Classic’s selected clones of commercial varieties were introduced in 2004, and in 2007 new hybrids hit the market. Some highly sun-tolerant strap caladiums varieties are described below.
Red varieties. These include ‘Red Frills’ and ‘Red Ruffles’. ‘Red Ruffles’ is the most notable recent introduction.
‘Red Ruffles’ is a University of Florida variety with a strong, deep-red color and a green border. It has a mounding habit, which makes it good for pots, hanging baskets and landscape borders or as an intermediate bedding plant. ‘Red Ruffles’ is more cold tolerant than other caladium varieties, providing color in the landscape further into the fall season than most other caladium varieties.
White varieties. Historically, white straps have been only erratically available because of their poor production performance. Among them were ‘White Wing’ and ‘Jackie Suthers’. Included in the new Classic introductions are ‘Mt. Everest’, ‘White Wonder’, ‘White Delight’, ‘White Marble’ and ‘White Star’, all of which are sun tolerant. ‘Mt. Everest’, ‘White Marble’ and ‘White Star’ are intermediate to tall white straps, whereas ‘White Delight’ is decidedly intermediate and ‘White Wonder’ is short to intermediate, useful in border plantings.
‘White Delight’ is a beautiful white variety that can stand full sun. It makes an excellent 4- to 10-inch pot with or without de-eying. ‘White Delight’ is similar in size and habit to ‘White Wing’ or ‘Jackie Suthers’; however, it is faster than ‘White Wing’ and whiter than either ‘White Wing’ or ‘Jackie Suthers’.
Pink varieties. Until recently, the only pink sun-tolerant strap caladium varieties commercially available were ‘Pink Gem’ and ‘Sweetheart’. Recent Classic introductions to the pink sun-tolerant strap group are ‘Candyland’, ‘Rose Mary’, ‘Starburst’ and ‘Victoria’.
‘Candyland’ makes an excellent 4- to 8-inch pot with or without de-eying. Similar to ‘Gingerland’, it has a white background but unlike ‘Gingerland’, ‘Candyland’ has pink spots and main veins and much broader leaves. In bright light it will have an overall pink appearance. In the spring of 2007, ‘Candyland’ placed in the top 30 in the University of Florida field trials.
Culture, Light and Fertilization
For potted plant production, fertilize with 75- to 100-ppm nitrogen constant feed of a 6-6-6 or 20-20-20 liquid formula or 300-ppm nitrogen weekly with fresh water in between. Alternatively, use standard rates of controlled-release fertilizer in the potting mix. Light levels should start out high and be kept as high as possible, up to 8,000 foot-candles.
In most cases, smaller bulbs produce smaller leaves and somewhat shorter plants.
For landscape production, use a 180-day controlled-release 19-2-17.
B-Nine (daminozide) and Bonzi (paclobutrazol) have proven to be useful for the production of quality pot caladiums. Recently, drenches of Topflor (flurprimidol) and Piccolo (paclobutrazol) have also shown to be effective. Growth regulators do not eliminate the need for good culture. Proper de-eyeing techniques, spacing and fertilization, timely removal from bottom heat, selection of the proper bulb size and variety for finished pot, and the use of growth regulators achieve the best habit for the pot-plant trade.
In the case of Bonzi, under Florida conditions, it should be applied twice: The first application is at the beginning of the growing period either in the form of a bulb soak — immediately after de-eying but before planting (15-30 ppm for 20 minutes) — or a drench when the pots are in spike (15-30 ppm). The second application is a heavy spray (to run-off) five to 10 days before shipping (30-ppm Bonzi plus 2,500-ppm B-Nine). The first is to improve the overall habit, and the second is to maintain the habit at retail level.
Insect and Disease Control
Caladiums are rarely damaged by insects or related pests. A good pest-monitoring program together with Marathon (imidacloprid) or other insecticide program is recommended for the control of aphids. A general all-purpose insecticide is usually sufficient.
Pythium can become problematic if you grow larger pots with longer crop times. A Subdue (mefenoxam) drench three weeks after planting or Subdue granules incorporated in the planting mix will help manage this problem. Heritage (azoxystrobin), Truban (etridiazole) or Banrot (thiophanate-methyl/etridiazole) will also provide effective Pythium control. Alternatively, RootShield (Trichoderma harzanium T-22) incorporated in the potting soil or applied as a post plant drench appears to be useful.
Varieties discussed above, with the exception of ‘Red Frills’, ‘White Wing’, ‘Jackie Suthers’ and ‘Pink Gem’, are patent protected. For more information about caladiums, please go to the ABBOTT-IPCO website at www.abbott-ipco.com .