sign in sign up
<<
Home , Cabbage, Kale

Ornamental and Production Brian E. Whipker, Extension Floriculturist Department of Horticulture, Iowa State University, Ames, IA 50011

(Reprinted from Whipker, B. E. 7996. Ornamental cabbage and kale production. North Carolina Flower Growers' Bulletin. 4 l(3): 1-5.)

Ornamental cabbage and kale have become increasingly popular as a fall flowering crop because of their long lasting colorful foliage. They will often remain colorful until temperatures drop below 20 OFand are well suited to areas of the Southeast which have mild winters. Ornamental cabbage and kale are also an excellent complement to garden chrysanthemums and fall pansies in increasing autumn sales. Ornamental cabbage and kale cultivars have red, pink, or white foliage. They are firther grouped by tvues constituting the ornamental leaf shape, with the round, smooth leaf iibbages and thgfeathered or fringed types constituting the ornamental kales. Table 1 Table 1. Characteristics of ornamental cabbage and kale cultivars (Adapted lists the characteristics of from McAvoy, 1994). some of the most popular cultivars. Name Color Growth Habit Leaf Tvpe Red Peacock Red Tall Feat hered Scheduling White Peacock White Tall Feathered Plants generally require Coral Queen Pink Medium-Tall Feathered between 21/2 to 3 months Coral Prince White (pink center) Medium-Tall Feathered of growth to achieve Red Feather Dark Red Very Tall Feathered marketable size, when White Feather White Very Tall Feathered produced in 6" pots. Red Pigeon Light Red Dwarf Round Allow an extra 2 weeks of White Pigeon White (pink center) Dwarf Round growth for 8" pots. For Pink Beauty Pink Dwarf, early Round northern locations, seeds Rose Bouquet Bright Red Dwarf, early Round should be sown in June, White Xmas White (pink center) Dwarf, early Round while for southern Red Sparrow Red Dwarf Fringed locations a July sowing is White Sparrow White Dwarf Fringed optimal. Prima Donna Light Red Tall Fringed White Lady All White Tall Fringed Seeding and Red Kamome Red Dwarf, early Fringed Containers White Kamome All White Dwarf, early Fringed takes around Fringed Red Chidori Dark Red Dwarf 10 days at 70 OF. White Chidori All white Dwarf Fringed Germination is best in the presence of light. Seeds can be sown increase in pH over the growing in plug flats, germination trays, or season. If alkalinity is higher than 2 directly into an 806 flat. Avoid letting meqL, consider using an acidic the plants become root bound in the fertilizer (as long as the N03-N to container before transplanting them. NH4-N ratio is greater than 2: 1) or Restriction of the roots will result in acid injection. Fertilize the plants with stunted plant growth. Transplant the a balanced fertilizer such as 20-10-20. seedlings into 6" or 8" pots "Ornamental cabbage and kale are not tolerant when of drought stress. This will result in the sufficient growth stalling of plant growth and the yellowing and has occurred. drop- of the lower leaves." If the plants have become too tall in the seedling For the seedling stage, fertilize at the flats. they should be planted deep (up rate of 50 to 100 pprn N on a constant to the first set of leaves). liquid feed basis. After transplanting into the final container, fertilize at the Spacing rate of 150 to 250 ppm N and K. The plants required adequate spacing Electrical conductivity should be to encourage growth and prevent foliar maintained between 1.0 and 2.0 mS/ diseases. Use 6" centers for 4" pots, cm. Some recommendations suggest 1 " to 12" centers for 6" pots, and 16 fertilization should be discontinued to 18" centers for 8" pots. during color. Excessive fertilization will prevent good coloration, but Substrate, Irrigation, and deficient levels of plant Nutrition nutrients will result in Substrate. Plants can be grown in any the yellowing and loss good quality soilless substrate that has of the lower leaves. La- good water holding capacity. If the Deficiency symptoms plants are to be grown outdoors, a are more likely to occur soil-based substrate or the addition of in a soilless s6bstrate sand may help avoid toppled plants that has a lower cation during windy weather. exchange capacity (the 1 ability to hold 6i2-J Irrigation. During the summer months nutrients) than in a soil- /m Wl the plants will require adequate based substrate. For the - moisture. Using an automated final three weeks of watering system similar to one used growth, a fertilizer r.ate on garden chrysanthemums will assist of 50 pprn N and K in irrigation. Ornamental cabbage and should be sufficient to kale are not tolerant of drought stress. allow the plants to This will result in the stalling of plant develop color and growth and the yellowing and drop of avoid deficiency the lower leaves. symptoms. Extensive research on the Nutrition. Maintain a substrate nutritional requirements of ornamental cabbage solution pH between 5.8 and 6.5 for and kale are not available, but best nutrient uptake. Irrigation water numerous studies have been alkalinity should be adjusted to a completed for cabbage. maximum of 2meqL (100ppm CaC03 Cabbage is susceptible to internal or 120 ppm HC03-) to avoid a general tipburn which appears as a browning Page - 7 of the tissue. It is caused by an cabbage and kale grown as a nonfood inadequate supply of (Ca) crop.) Luczai ( 1992) recommended (Becker, 1986). Members of the using B-Nine at 1,500 to 3,000 ppm to cabbage family (crucifer crops) achieve desired height reduction. require high levels of Ca, and McAvoy ( 1994) recommended fertilization rates of 50 to 100 pprn Ca multiple applicatior of B-Nine at may be beneficial if your irrigation 1,500 ppm. water is low in calcium content. Black is Research another conducted at internal Table 2. Foliar concentrations of elements in Purdue disorder of cabbage plants ( oleracea var. University cabbage which capitata). Values are from wrapper leaves of (Whipker et al., appears as an cabbage plants sampled near harvest when the 1994) internal heads had formed (adapted from D.J. Reuter compared B- blackening of and J.B. Robinson (eds.). Plant Analysis: An Nine at 2,500 the cabbage Interpretation Manual) and 5,000 ppm; head. It is Element Units Adequate Ranae Bonzi at 15 thought to be a ppm; and N YO 2.5 to 4.0 nutritional Sumagic at 5 P YO 0.25 to 0.5 imbalance that ppm on two K O/O 2.0 to 4.0 occurs when ornamental Ca YO 1.5 to 3.0 the kale cultivars. O/O 0.2 to 0.6 (K) levels are Mg Na O/O <1 .o On ‘Coral low and the B PPm 20 to 60 (P) Prince’, foliar cu PPm 5.2 levels are high Fe PPm 50 to 200 spray (Becker, applications of Mo PPm 0.3 to 0.5 1986). Boron Zn 10 to 200 Sumagic and (B) deficiency PPm B-Nine at has also been 2.500 and reported to 5,000 pprn had cause a brown spotting of the greatest effect on plant height, heads ( and Helms, 1990). with a reduction of 16%, 18%, and Growers should make sure that B is 26%, respectively, compared to the part of their fertilizer mix and that Ca control (Table 3). These treatments is not being added in excessive resulted in plants with uniform shape. amounts (excessive Ca can tie up B, At the rate used, Bonzi had little effect making it unavailable to plants). on reducing plant height and resulted Maintain a substrate pH between 5.8 in a more open rosette head. The and 6.5 to enhance B availability (B PGRs had no influence on ‘Coral availability decreases at pHs above Prince’ plant diameter. 6.5). Foliar analysis interpretation values for cabbage are listed in Table 2 All PGR treatments reduced ‘Red and may be useful for ornamental Kamome’ shoot elongation by at least cabbage and kale production. 14% compared to the untreated plants (Table 3). Although ‘Red Kamome’ Growth Regulators plant diameter was reduced by B-Nine Ornamental cabbage and kale are (both rates), the shoot (head) growth unsuitable as a warm season crop was very uniform. Bonzi and Sumagic because hot summer temperatures applications resulted in reduced plant cause excessive stem elongation. Stem height, with no change in plant elongation can also occur with crops diameter. Plants treated with Bonzi, grown for fall sales, but it may be although marketable, had an avoided by use of the plant growth undesirable head due to a more open regulator (PGR) applications. (PGRs rosette and looser appearance as a can only be applied to ornamental result of increased internode length. Page - 8 The variations in cultivar response to in cultivar growth habits in order to the PGRs observed in this study is achieve the desired growth effects. probably due to differences in vigor and growth characteristics of the two Temperatures cultivars. 'Coral Prince' is an Optimal growth occurs with plants upright' aggressive cultivar that grew grown in outdoor production, similar 26% taller than 'Red Kamome' when to a system used with garden no PGR was applied. chrysanthemums. Temperatures inside

Table 3. Chemical growth retardant effect and cost comparison on growth of ornamental kale 'Coral Prince' and 'Red Kamome' (Adapted from Whipker et a/,, 1994).

Coral Prince Red Kamome Chemical Conc Diam Diam cost per Treat ment (PPm) Ht (in) (in) Ht (in) (in) 100 ft'

Control ------12.6 15.7 10.0 14.4 ------B-Nine 2500 10.4 16.3 7.3 12.8 $0.87x 5000 9.3 15.4 7.6 13.0 $1.74 Bonzi 15 11.6 16.0 8.3 14.4 $0.77 Sumagic 5 10.6 15.3 8.5 13.8 $1.52 ***y ** ** Significance NS LSD 1.1 1.4 1.0

'Cost comparison of plant growth regulators applied to ornamental kale. Chemical cost (rounded) based on the use of foliar applications of plant growth regulators using a volume of 112 gallon of spray per 100 ft2 of bench area. Corresponding to the cost of $71 per pound of B- Nine, $103 per quart of Bonzi, or $76 per quart of Sumagic. Y Nonsignificant (NS) or significant at P 0.01 (**) or 0.001 (***).

the greenhouse may be too hot and The choice of PGRs to control the may be detrimental to plant growth. growth of ornamental kale should be After the plants have achieved based on the response of the cultivar marketable size, they must be exposed and the cost of the PGR (Table 3). to 3 to 5 weeks of temperatures below 'Coral Prince' was controlled for the 55 to 60 OFto allow the plants to lowest cost ($0.87 per 100 square develop coloration. feet of bench area) by using B-Nine at 2,500 ppm. For 'Red Kamome', Pests and the desired control of growth was Diseases "After the plants have obtained for the lowest cost by using Insect and Bonzi, at the cost of $0.77 per 100 Related Pests. achieved marketable square feet of bench area, at the rate The most of 15 ppm. Although B-Nine at common insect size, they must be ex- 2,500 ppm also provided an and related pests inexpensive height control of 'Red that attack posed to 3 to 5 weeks of Kamome', it also reduced plant ornamental temperatures below 55 to diameter by about 1 'I. Rates of B- cabbage and kale Nine lower than the 2,500 ppm used are: aFhids, 60°F to allow the plants in this study may be effective in , flea reducing plant height of both beetles, slugs, and to develop Coloration." cultivars at a more economical cost, whiteflies. For a without reducing 'Red Kamome' complete 1is t i ng plant diameter. The ultimate of pesticides selection of optimal PGR rates will labeled for each have to be based on the differences Page - 9 of these pests, readers should refer to sweetpotato whitefly is the most “Greenhouse ornamental insect and difficult to control): acephate related control”, pages 5- 18 of the (OrtheneB), azadirachtin (Azatin@, October, 1995 NCCFGA Bulletin or Margosan-O@), endosulfan refer to the 1996 (Thiodan),horticultural oil (Sun N.C. Agricultural Spray@, Ultra-Fine@), imidacloprid Chemicals Manual. (Marathon@), insecticidal soap ‘I The most common Some control (MPedeB), and kinoprene (Enstar measures are listed 1163)). insect and related below: Diseases. There are a number of pests that attack (many pathogens that attack ornamental ornamental cabbage ; mainly cabbage and kale. The followin cabbage and disease descriptions are adapte cffrom and kale are: aphid): Latin and Helms, 1990. aphids, caterpillars, acephate Root Rots (Pythium spp. and (OrtheneB), Phytophthora spp.). Symptoms include: flea beetles, slugs, diazinon (Knox- a general decay of the roots. Affected Out@), endosulfan plants typically exhibit wilting, due to the and whiteflies. I1 (Thiodan), destruction of the root system and the horticultural oil (Sun resulting inability of the rodt system to Spray@, Ultra- supply adequate amounts of water to the Fine@), imidacloprid (Marathon@), top growth. Control with fungicide and insecticidal soap (M-Pede@). drenches if symptoms appear (etridiazole Caterpillars ( [Truban@,BanrotB] and metalaxyl [Trichoplasia nil, cutworms [black [Subdue@]). cutworm (Agrotis ipsilon) and Alternaria leaf spot (Alternaria variegated cutworm (Peridroma brassicae). Symptoms include: round, saucia) are the two most common in brown lesions on infected leaves and North Carolina], oval or elongated lesions on stems. larvae [Plutella xylostella], and These lesions can enlarge to the size imported [Artogeia of a dime and are characterized by the rapae]): acephate (Orthenea), presence of concentric rings within the azadirachtin (Azatin@, Margosan- dead tissue. Control with sanitation O@), Bacillus and applications of fungicides thuringiensis (Bt) (iprodione [Chipco 260 19@] (Dipec@, r-1- -. Victory@), and bifenthrin Terraguard@]). (TalstarB), and Black leg (Phoma pyrethrins. 1ing urn). Flea beetles Svmptoms include (many genera and elongated, light species): acephate brown, sunken areas with purplish (OrtheneB), margins near the bifenthrin -=/-- soil line. Stem (Tals tar@), ------//A,, lesions expand and fluvalinate girdle the entire (Mavrikm), and . stem, killing the pyrethrins. plant. Control with sanitation. Onion (Thrips tabaci): ( pv acephate (OrtheneB), bifenthrin campestris). Symutoms of the initial (TalstarB), fluvalinate (MavrikB). infection is the presence of small, yellow- Slugs (many genera and species): brown, V-shaped areas at the leaf margin. metaldehyde (Deadline Bullets@, As lesions enlarge, the nearby veins turn black. A cross-section of an infected stem Snarol@). cut near the soil surface will show a Whiteflies (many genera and species; Page - 10 distinct ring of decayed tissue. Control with sanitation and use disease resistant ANNUALS from page 5 cultivars. Club root (Plasmodiophora brassicae). Svmptoms include stunted and wilted tops and an enlarged root Conclusions: system. Control with sanitation. Downy mildew (Peronospora Clearly, lighting treatments are very parasitica).Svmptoms are the beneficial for either hastening or appearance of purplish, irregular spots delaying flowering of some bedding on the leaves. During cool, wet plant species. Clearly, we can control weather, the spots will enlarge and flowering precisely on some of these become yellow-brown in color. A crops. The question arises as to how white mold on the underside of the to best use this information. We are leaves may also develop. Control with currently finishing data analysis from sanitation and good air flow. Apply last year to determine the ‘best’ fungicides if needed (mancozeb prefinishing environments for [Manzate@]). petunias, pansies, nierembergia and Fusarium yellows (Fusarium violas. We will be validating these oxysporum conglutinans). Symptoms treatments in commercial greenhouses include plants with a dull cast, and lower this fall. Results of this work will be leaves that turn yellow-green in color. reported as soon as possible after that. Control with sanitation and use disease In addition to this work, we are also resistant cultivars. studying the environmental effects on flowering of many of the new References vegetatively propagated bedding American Takii, Inc. 1992. Cultural information on flowering kale. p. 4. plants . Becker, R.F. 1986. Nonpathogenic disorders of cabbage. Cornell Ext. References: Service. Bingham, G. 1991. Fall flowering kale. Floriculture Indiana. 5(3): 12. Gill, S., Cathey, H.M. 1976. Growth T. Blessington, and E. regulators, Chapter 17, pp. 177-189 Dutky. 1993. IPM for ornamental in Bedding Plants, A Penn State cabbage and kale. Manual (J.W. Mastalerz. Ed.)2nd GreenhouseGrower. 11(6):24-26. Edition. Pennsylvania Flower Latin R. and K. Helms. 1990. Growers, Univ. Park, PA. Identification and Control of Crucifer Diseases, BP-22, Purdue Post, K. 1942. Effects of daylength University Coop. Ext. Service. and temperature on the growth and Luczai, R. T. 1992. Flowering cabbage flowering of some florist crops. and kale: ideal for use in late fall Cornell Agr. Exp. Sta. Bul., 787. landscapes. PPGA News. 23(4):2-3. 72 PP. McAvoy, R.J. 1994. Cultural tips for ornamental cabbage and kale. Conn. Greenhouse Newsletter, No. 180, June/July. p. 13-15. Nau, J. 1991. Cabbage and kale, ornamental. Ball Red Book. Geo. J. Ball Publishing, W. Chicago, IL p. 410-412. Whipker, B.E., R.T. Eddy, and P.A. Reminder! Hammer. 1994. Chemical growth- retardant height control of Have you mailed your 1997 ornamental kale. HortScience 29: 329. M.C.F.G.A. Annual dues ? If not, please do so today. Thanks for your support !

Page - 11