Caladiums (Caladium species) are in the arum (Araceae) family and native to Central and South America. They are hardy only to USDA zone 9 or 10; therefore, caladiums should be used as annuals in South Carolina gardens. These tropical foliage plants are grown for their decorative, multicolored foliage. They are used in containers, borders, or as bedding plants throughout the state to provide summer color in shady locations and will thrive in heat and humidity.
Caladium leaves are combinations of red, pink, green, and/or white, with colored midribs and contrasting backgrounds and borders. The varied leaf colors and patterns create many uses for caladiums in the landscape. The leaves do not have stems, but instead originate on long petioles emerging directly from the tuber. They may produce a greenish-white spathe flower similar in appearance to jack-in-the-pulpit or calla lily. Caladiums are grown for their beautiful foliage; therefore, remove the flower as it takes food away from the leaf production and reduces the tuber size.
Fancy and lance-leafed cultivars are the two main types of caladiums. Fancy-leafed types have large heart-shaped leaves, grow best in semi-shade, and may reach a height of 12 to 30 inches, depending on cultivar and growing conditions. The lance or strap-leafed types have narrow, elongated leaves with ruffled leaf margins. The lance types tend to produce more leaves than the fancy-leafed cultivars. Use both as accent plants in borders, hanging baskets, window boxes, and patio planters.
Fancy-leafed caladiums grow between 12 and 30 inches tall depending on cultivar and growing conditions. Lance-leafed caladiums are generally a little smaller, usually less than 12 inches tall.
Caladiums are not hardy year-round, although it is possible to overwinter the dry tubers indoors. They grow to full size in one season.
Mass plantings of caladiums create a focal point in the landscape. They provide a striking contrast with the green foliage of other plants, especially when planted in the foreground. White cultivar selections are excellent choices for mixing with ferns, hostas, and Lenten roses to brighten a shady area.
Caladiums need protection from full, hot sun for best growth and color. Some newer cultivars will tolerate full sun for a couple of hours daily, but all prefer dappled or moderate shade with protection from hot afternoon sun.
Caladiums require warm, moist, well-drained soil to grow. Planting tubers in cool soil results in slow growth or tuber rot. A good rule of thumb in determining when to plant out caladiums is to set them out at the same time okra seed is planted in the vegetable garden. Do not plant the tubers or plants until the soil temperature reaches 70 °F.
Caladiums may be grown from tubers or plants. Large tubers have more leaf buds than small tubers; therefore, producing more abundant and better displays.
Each caladium tuber has a large central bud surrounded by several small buds. Most caladium varieties produce only a few colorful leaves when the prominent central bud is allowed to grow. Remove the central bud to allow the tuber to produce many more shoots and leaves. Use the tip of a sharp knife to lift out the large central bud, being careful not to injure any of the surrounding small buds. Tubers should be planted 1½ to 2 inches deep and 8 to 14 inches apart with the eyes (buds) pointing up.
Water frequently and thoroughly, keeping the soil evenly moist to touch but not saturated. If planted in a container, be sure it is well-drained and has a drainage hole, as caladiums rot when kept too wet.
Fertilize caladiums growing in containers every two weeks with a soluble liquid fertilizer to promote strong foliage growth, such as Miracle-Gro® Liquid All Purpose (8-7-6). Another fertilizer option is to use a 6 month time-release fertilizer, such as Osmocote® Outdoor & Indoor (15-9-12 plus micronutrients). Caution should be taken not to use a fertilizer too high in phosphorous, the middle number of the fertilizer analysis. If grown in the ground, do a soil test to determine what additional nutrients the caladiums may require. For more information on soil testing, see HGIC 1652, Soil Testing. In the absence of a soil test, use a 12-6-6 fertilizer every six weeks. The coastal areas of South Carolina tend to have soils naturally high in phosphorus. In that case, use a 15-0-15 fertilizer without phosphorus.
Save caladium tubers for planting next year by digging the tubers in the fall before the leaves have lost all color. Spread them out and allow them to dry for a one to two weeks. Cut or pull the dry foliage from the tubers and remove all dry soil and pack in dry peat moss, perlite, or vermiculite for storage. To prevent rot, the tubers should not touch each other. Store them in a dry, warm place where the temperature will not drop below 50 °F.
Starting with new tubers each year may give better results since second year foliage is usually not as good as the first year. White-foliaged caladium tubers tend to store better than those of other types.
Tuber rot is a fungal decay of tubers in storage or during the growing season. Select disease-free tubers for planting. Store tubers properly to avoid high humidity and in a dry warm place where the temperature is above 50 ºF. Never store caladium tubers in the refrigerator. Tubers purchased in early spring should be kept at room temperature. Leaf spot causes lower leaves to develop light tan to brown spots. Remove and dispose of diseased leaves as they appear.
The burning of the edges of older leaves and scorching of leaves usually are the result of fertilizer touching the leaves; therefore, always wash off any fertilizer that may be on the leaves. Other problems are watering during the hot part of the day or too little water.
- ´Aaron´ is white with green margins and has some sun tolerance.
- ´Candidum´ is an old cultivar that has white leaves with green veins.
- ´Carolyn Whorton´ has pink leaves with red veins and green margins.
- ´Fire Chief´ is a dark pink, with limited sun tolerance.
- ´Florida Elise’ has green leaves with rose pink brush strokes and speckles and tolerates more sun.
- ´Florida Fantasy´ is white with red veins.
- ´Freida Hemple´ is deep red with green margins and no sun tolerance.
- ´Gypsy Rose´ has pink veins with green blotches.
- ´June Bride’ is white with green margins.
- ´Kathleen´ is red with green margins.
- ´Marie Moir´ is whitish green with red spots.
- ´Moonlight´ has luminescent white leaves with a faint green margin.
- ´Pink Beauty ´ has medium green leaves with hot pink veins and medium pink splashes.
- ´Pink Cloud´ is pink with green margins and some sun tolerance.
- ´Postman Joyner´ is a well-known dark red with green margins.
- ´Raspberry Moon’ has vibrant green leaves with raspberry splotches.
- ´Red Flash´ is dark red, with fuchsia spots, green margins and good sun tolerance.
- ´Strawberry Star´ has white leaves with red square-like flecks and speckles and green veins.
- ´White Christmas´ is a popular white leafed cultivar.
- ´White Queen´ is white with red veins and has some sun tolerance.
- ´Caloosahatchee´is white with a green margin.
- ´Candidum Jr.´is a dwarf white caladium with green veins.
- ´Florida Sweet Heart´ is mauve pink with green margins.
- ´Gingerland´ is white with red blotches and a green margin.
- ´Miss Muffett´ is a dwarf caladium. Its leaves are green with white veins and red blotches. This cultivar has no sun tolerance.
- ´Peppermint´ has white and red candy cane striped leaves with green margins.
- ‘Pink Gem’ is pink and excellent for hanging baskets.
- ‘Pink Symphony’ is pink with green veins.
- ‘Lance Whorton’ is red with white blotches and a green margin.
- ‘Red Frill’ is red and excellent for hanging baskets.
- ‘Rosalie’ is red with green margins.
- ‘White Wing’ is white with green margins.