University of FloridaSolutions for Your Life

Download PDF
Publication #ENH1042

'Summer Rose' Caladium—A University of Florida Cultivar for Containers and Landscapes1

Zhanao Deng and Brent K. Harbaugh2

Cultivated caladiums (Caladium ×hortulanum) are known for their bright, colorful leaves and ease in growing and are used widely in containers, hanging baskets, and landscapes. Commercial caladium plants are grown from tubers. Over 95% of the caladium tubers used in the world are produced in Florida.

The predominant leaf colors exhibited in caladium are white, red, and pink. According to a 2003 survey, pink fancy-leaved cultivars represented 25% of the Florida tuber producing industry (Deng et al. 2005). 'Rosebud' is ranked fourth for acreage grown (11% of total acreage) among the pink fancy-leaved cultivars. This cultivar is well liked for its unique pattern of bright pink color. However, tuber yield in 'Rosebud' has been rather low and tuber production has been rather costly, due to a disorder called “grassy tuber." This disease results in diminutive plants with many small leaves and reduction of tuber size and yield (Polston et al. 1991). Tuber producers have to manage this disorder by rouging symptomatic plants manually. For many tuber producers, costs of rouging and reduced yields make production of 'Rosebud' unattractive economically and a replacement cultivar would be welcome.

'Summer Rose' is similar to 'Rosebud' in color and container-performance, except that de-eyed tubers sprout several days earlier and petioles are red-purple at the leaf attachment and gradually darken to brown at the petiole base. Tuber production and field performance of 'Summer Rose' were better than 'Rosebud', adding another benefit to both tuber producers and landscapers. 'Summer Rose' would make a good replacement for tuber producers desiring a new cultivar to replace 'Rosebud'.

Origin

'Summer Rose' was derived from a cross between 'Aaron' and a seedling, S-25, which was from a cross of 'Fire Chief' × 'Torchy'. 'Aaron' was selected as the female parent for its large leaves and tubers. 'Fire Chief' and 'Torchy' were selected for their vivid red veins and interveinal areas. Ancestry of 'Aaron', 'Fire Chief' and 'Torchy' are unknown.

Description

Jumbo tubers of 'Summer Rose' are multi-segmented, usually bearing three to four dominant buds. Tuber surfaces are brown with the cortical area very light yellow.

Leaves are peltate, sagittate-cordate, with palmate-pinnate venation. The center veins are red-purple. The upper surface has an irregular dark green margin bordering the entire leaf, except for the basal leaf sinus, where it is grayed-purple. Interveinal areas in the center of the leaf are red-purple, but this is bordered by a green-white speckling on a green background. Petioles are red-purple at the leaf attachment and gradually darken to brown at the petiole base.

'Summer Rose' plants grown from 1-inch tuber propagules for about 4 months in full sun in ground beds had an average height of 20 inches. Their leaves averaged 12 inches long and 8 inches wide, larger than leaves of 'Rosebud', which were 9 inches long and 6 inches wide. The largest leaves on plants grown in a 50% shaded greenhouse produced from an intact, No. 1 tuber in a 5-inch pot averaged 10 inches long and 8 inches wide 7 weeks after planting. This size was very similar to other pink cultivars tested.

Tuber Production

'Summer Rose' was evaluated for tuber production at the GCREC–Bradenton, FL, during 2003 and at the UF/IFAS GCREC–Dover, FL, in 2004. The soil in Bradenton was an EauGallie fine sand with approximately 1% organic matter and a pH of 6.2, and the soil in Dover was a Seffner fine sand with approximately 1% organic matter and a pH of 6.5. Plants were grown in a plastic-mulched raised-bed system. The beds were 36 inches wide and 8 inches high with 1-inch caladium seed pieces planted 6 inches apart in three rows (Bradenton) or 12 inches apart in two rows (Dover). Osmocote(R) controlled-release fertilizer (15-9-12, 8 to 9 months) was applied to the bed surface when shoot tips were emerging from the soil with N at 300 pounds per acre.

'Candidum' was grown on 120 acres in a 2003 survey and was among the top two caladium cultivars ranked based on production acreage (Deng et al. 2005). 'Summer Rose' tuber production was excellent with tuber weights nearly 1.3 and 1.6 times higher than 'Candidum' in 2003 and 2004, respectively. Also, its production index (an economic indicator of crop value) was greater than 'Candidum' in both years (1.3 or 1.4 times greater). Similarly, 'Summer Rose' had higher yields than 'Rosebud' as seen in tuber weight (1.3 and 1.8 times higher) and production index (1.2 and 1.3 time higher) measurements. Although 'Summer Rose' did not have the greatest number of marketable tubers, it produced 40 tubers from 30 chips and had as many tubers as or more than other cultivars tested. There was also a greater percentage of tubers in the mammoth and jumbo grades compared to 'Rosebud' and 'Carolyn Whorton', and these grades have a high market value.

Container Forcing

'Summer Rose' tubers were forced in 4½-inch containers, and its growth was compared to three pink-fancy commercial cultivars. No. 1 tubers were planted in a peat/vermiculite mix (Vergro Container Mix A) on 24 June 2002. The study was conducted in a glasshouse with 50% light exclusion during the summer in Bradenton, FL. Average daily temperatures ranged from a low of 70°F at night to 85°F in the day during the experiment. Plant performance of 'Summer Rose' in containers was similar to plant performance of the other cultivars tested. Noticeable differences included fewer days to sprout for 'Summer Rose' than 'Rosebud' for de-eyed tubers and greater plant height for de-eyed 'Summer Rose'. Since 'Rosebud' is known as an excellent pot plant, these results indicate 'Summer Rose' also has potential for use as a potted/container plant.

Figure 1. 

'Summer Rose' forced in a 4-inch-container using one No. 1 tuber.


Credit:

UF/IFAS Gulf Coast REC


[Click thumbnail to enlarge.]

Landscape Performance

'Summer Rose' and several commercial cultivars were grown under full-sun conditions in 2003 and 2004. Plant height, number of leaves, and foliar characteristics were recorded about 4 months after planting. 'Summer Rose' was taller with larger leaves than 'Rosebud' but similar in height and leaf size to 'Candidum' and 'Carolyn Whorton'. It had excellent performance ratings all through the growing season.

Figure 2. 

Plants of 'Summer Rose' in a landscaped area.


Credit:

UF/IFAS Gulf Coast REC


[Click thumbnail to enlarge.]

Summary

In summary, 'Summer Rose' is intended for use in containers and the landscape. It should perform well in partial shade or full sun conditions. Although extensive research and evaluations of this cultivar have been performed on small acreages, tuber producers are encouraged to plant only limited quantities of 'Summer Rose' until they have gained experience in producing this cultivar. Standard postharvest treatment of tubers is recommended (Harbaugh and Tjia 1985) and preplant hot-water treatment of tubers is encouraged to prolong their life.

Availability

A plant patent (PP20,446) has been issued for 'Summer Rose' by the United States Patent and Trademark Office, and production of this cultivar is to be with a licensing agreement with the Florida Foundation Seed Producers, Inc., PO Box 309, Greenwood, FL 32443. Information on tuber availability and propagation agreements can be obtained from the Florida Foundation Seed Producers, Inc (http://www.ffsp.net/varieties/caladium/).

Literature Cited

Deng, Z., B.K. Harbaugh, R.K. Schoellhorn, and R.C. Andrew. 2005. 2003 Survey of the Florida caladium tuber production industry. ENH 1007. Gainesville: University of Florida Institute of Food and Agricultural Sciences. http://edis.ifas.ufl.edu/EP258

Harbaugh, B.K. and B.O. Tjia. 1985. Commercial forcing of caladiums. Circ. 621. Gainesville: University of Florida Institute of Food and Agricultural Sciences.

Polston, J.E., M.R. Evans, and J.H. Tsai. 1991. "Investigation of the etiology of grassy tuber of caladium." Proc. Fla. State Hort. Soc. 104:334–336.

Wilfret, G.J. 1993. "Caladium," p. 239–247. In: A. de Hertogh and M. le Nard (eds.). The physiology of flower bulbs. Elsevier, New York.

Tables

Table 1. 

Performance of plants grown from 1-inch tuber propagules in ground beds in full sun.

Cultivar

 

Leafz

Overall plant performancey

 

Plant height z

Leavesz

Length

Width

 

(in)

(number)

(in)

(in)

Early

Middle

Late

Candidum

18.1

13

11.0

7.1

3.3

3.7

3.5

Carolyn Whorton

18.9

16

13.0

8.7

3.0

4.6

4.5

Rosebud

16.5

20

9.1

6.3

2.5

3.2

2.0

Summer Rose

20.5

17

12.2

8.3

4.5

4.5

4.5

z Values presented are means of three replications with three plants measured per plot per year, averaged over 2 years (2003 and 2004).

y Overall plant performance was rated July 22 (early), August 31 (middle), and November 16 (late), 2004.

Table 2. 

Plant performance for caladium cultivars grown from No. 1 tubers planted 24 June, 2002, in 4.5-inch containers in a 50% shaded glasshouse, Bradenton, FL. Values represent the means of five plants produced from intact or de-eyed No. 1 (1.5 to 2.5-inch-diameter) tubers planted individually per container.

 

Days to sproutz

Plant ht (inch)

Leaves (no.)

Leaf length (inch)

Leaf width (inch)

Cultivar

Intact

De-eyed

Intact

De-eyed

Intact

De-eyed

Intact

De-eyed

Intact

De-eyed

Calypso

14

13

15.4

15.7

11

19

9.8

7.9

7.1

5.5

Carolyn Whorton

20

18

16.9

16.1

10

14

10.6

8.3

7.1

5.5

Rosebud

20

23

15

12.6

12

19

9.4

6.7

5.1

5.1

Summer Rose

18

17

14.2

15.4

9

22

9.8

8.3

7.5

6.3

z Number of days from planting to the first unfurled leaf.

Table 3. 

Tuber weights, production index, and tuber grade distribution of caladium cultivars harvested in 2003 and 2004.

 

Tuber

Tuber distributiony (%)

Cultivar

Weight (lb)

Production indexz

Marketable (number)

Super mammoth

Mammoth

Jumbo

No. 1

No. 2

 

Year 2003

Candidum

6.1

98

33

1

12

30

43

14

Carolyn Whorton

6.3

101

39

0

9

28

40

24

Rosebud

5.8

109

45

0

4

24

45

27

Summer Rose

7.8

126

40

0

8

47

40

5

 

Year 2004

Candidum

6.3

96

35

2

6

27

54

12

Carolyn Whorton

9.4

132

53

0

9

20

45

26

Rosebud

5.6

102

49

0

2

18

47

33

Summer Rose

10.1

132

40

0

15

42

32

12

z The production index is an indicator of economic value of the crop harvested and is calculated as N (No. 2s) + 2N (No. 1s) + 4N (Jumbos) + 6N (Mammoth) + 8N (Super Mammoth); where N = number of tubers in each grade.

y Tubers graded by maximum diameter; No. 2 (1 to 1.5 inches), No. 1 (1.5 to 2.5 inches), Jumbo (2.5 to 3.5 inches), Mammoth (3.5 to 4.5 inches), and Super Mammoth (>4.5 inches).

Values presented are means of three replications with 30 propagules per 13.5 square feet plot per year.

Footnotes

1.

This document is ENH1042, one of a series of the Environmental Horticulture Department, UF/IFAS Extension. Original publication date June 2006. Revised November 2009, March 2013, and November 2016. Visit the EDIS website at http://edis.ifas.ufl.edu.

2.

Zhanao Deng, professor; and Brent K. Harbaugh, professor emeritus, UF/IFAS Gulf Coast Research and Education Center, Wimauma, FL 33598.


The Institute of Food and Agricultural Sciences (IFAS) is an Equal Opportunity Institution authorized to provide research, educational information and other services only to individuals and institutions that function with non-discrimination with respect to race, creed, color, religion, age, disability, sex, sexual orientation, marital status, national origin, political opinions or affiliations. For more information on obtaining other UF/IFAS Extension publications, contact your county's UF/IFAS Extension office.

U.S. Department of Agriculture, UF/IFAS Extension Service, University of Florida, IFAS, Florida A & M University Cooperative Extension Program, and Boards of County Commissioners Cooperating. Nick T. Place, dean for UF/IFAS Extension.