Ornamentals and Flowers Apr. 2002 OF-29 Pikake A Fragrant-Flowered Plant for Landscapes and Lei Production Kenneth W. Leonhardt and Glenn I. Teves, Department of Tropical Plant and Soil Sciences ikake is the Hawaiian name for a Varieties Pjasmine, Jasminum sambac, which Four distinct flower types can be dis­ is one of about a dozen Jasminum spe­ tinguished in Jasminum sambac. One cies grown in Hawaii as ornamentals. is the single flowered variety with white 3 The name is adapted from the word petals that are ovate to acute, with a ⁄4– 1 “peacock,” because the Hawaiian Prin­ 1 ⁄4-inch diameter flower. This is the cess Kaiulani reportedly was fond both variety commercially grown in Hawaii of this flower and the bird, according as a lei flower. to Marie Neal (In Gardens of Hawaii). A semi-double variety has flowers J. sambac is known as sampaguita in with elongated white petals forming a 3 1 the Philippines, where it is the national flower ⁄4–1 ⁄4 inch in diameter. This flower, gunda mallige in India, mo li in Pikake buds strung crosswise, variety is not suited for lei making, be­ parts of China, and Arabian jasmine in forming a “rope” lei. cause the stems on the flower buds can­ the mainland USA. It is grown com­ not be pushed into the flower bud be­ mercially in India, Thailand, China, and the Philippines low it due to the greater number of petals. for its fresh flowers, which are also used to make per­ The rose pikake is a double-flowered variety with fume and as flavoring for tea. In Hawaii, pikake is grown white, rounded petals. The diameter of an open flower is 3 1 in landscapes and gardens and by commercial produc­ ⁄4–1 ⁄4 inch. The name comes from its structural resem­ ers of lei flowers. blance to a rose flower. Rose pikake produces fewer flow­ ers per plant than the single or semi-double varieties. Description A multi-whorled variety has petals so packed that it 3 3 Jasminum sambac, from the olive family (Oleaceae), is resembles a small, white, ⁄4–1 ⁄8 inch diameter carnation. a native of India. It is a fragrant-flowered shrub, 2–3 This variety, like the rose pikake, produces fewer flow­ feet wide and up to 6 feet tall, that is fairly hardy and ers compared to the single and semi-double varieties. drought resistant. It has a moderate growth rate in spring Single and semi-double varieties have their peak and summer but grows slowly during cool seasons. It flower production from March to September, with very has downy branches bearing rich green, rounded to oval, few flowers produced during the winter months. The paired leaves with prominent veins. The plant has both rose and multi-whorled pikake have their peak flower 1 3 bushy and viny growth characteristics. The ⁄2– ⁄4-inch production from April to August, with very few flowers cream-white flowers are borne at branch terminals ei­ produced during the remaining months. These flower­ ther singly or in clusters on new growth. The unopened ing periods may vary, depending on the location and the bud is oval, and the open flower is star-shaped. weather conditions of the particular year. Published by the College of Tropical Agriculture and Human Resources (CTAHR) and issued in furtherance of Cooperative Extension work, Acts of May 8 and June 30, 1914, in cooperation with the U.S. Department of Agriculture. Andrew G. Hashimoto, Director/Dean, Cooperative Extension Service/CTAHR, University of Hawaii at Manoa, Honolulu, Hawaii 96822. An Equal Opportunity / Affirmative Action Institution providing programs and services to the people of Hawaii without regard to race, sex, age, religion, color, national origin, ancestry, disability, marital status, arrest and court record, sexual orientation, or veteran status. CTAHR publications can be found on the Web site <http://www2.ctahr.hawaii.edu> or ordered by calling 808-956-7046 or sending e-mail to [email protected]. OF-29 Pikake CTAHR — Apr. 2002 Propagation Fertilizer Propagation may be done by layering, but only a few A soil test to determine the nutrient status of the soil is plants can be obtained from each parent plant. This may recommended. Generally, a fertilizer such as 10-30-10 be the preferred method to propagate a few plants for or 10-10-10 is recommended for good flower produc­ the home garden. Mass propagation for commercial tion. Fertilizer is applied when the plants are pruned purposes is more feasible using cuttings. Make cuttings during the winter months and two to three times during of mature (1–2-year-old) wood. Use a rooting compound the rest of the year. The fertilizer application rate will with 0.3% NAA or IBA before sticking the cuttings 1–2 depend on the soil nutrient levels, but 20–30 lb of a com­ inches into a clean, well drained medium such as a mix­ plete fertilizer per 1000 sq ft of planting per year (made ture of equal parts peat and perlite. Then place the cut­ in three or four applications) is generally adequate. An ting trays on a protected bench with intermittent mist or alternative to broadcasting granular fertilizer is to de­ in a shaded greenhouse with high humidity. Rooting time liver liquid fertilizer with the irrigation water. Foliar is 2–3 weeks. After the cuttings have rooted, plant them sprays of iron and other micronutrients may be required in containers with a rich loam soil and place them in under intensive cultivation. Diluted foliar fertilizer can brighter sun in preparation for field planting. be included in pesticide spray applications. Soil Pruning Good results are obtained when pikake is grown in rich Pruning is usually done during November–January, when loam, silty clay loam, or sandy soils with irrigation. Good the plants are not producing flowers. The plants are drainage is essential because waterlogging kills almost trimmed back with a hedge trimmer to allow passage all species of Jasminum. The soil pH should be 6.0–6.5. between the rows and to facilitate harvesting. The plants may also be pruned back once or twice during the flow­ Growing conditions ering months to induce a heavier flower set. Pruning Long days and hot weather favor good flower produc­ will induce lateral branching and thereby promote flow­ tion and large flowers. Pikake grows best in dry loca­ ering, because pikake produces flowers only on the ter­ tions, and it flowers most profusely when grown in full minal ends of new growth. See more on pruning under sun. Under shade, (such as beneath a tree or under the Manipulating flowering, below. eave of a house) the plant does not grow as well and Old plants are rejuvenated by pruning the whole produces fewer flowers. Daytime temperatures of 80– plant back to a height of about 2 feet. Root suckers are 90°F (27–32°C) and nighttime temperatures of 70–80°F unproductive and should be eliminated. (21–27°C) are ideal. Lowland, leeward areas free from cool mountain breezes provide these conditions. If night Pests, diseases, integrated pest management temperature drops below 70°F (21°C), flower produc­ Many insect and mite species can be problems on pikake tion and size are reduced. One night of temperatures in if they are not controlled. We recommend the integrated the low ‘60s (15–17°C) can shut down flowering for 1– pest management (IPM) approach. IPM is based on pre­ 2 weeks. dicting the need for a control measure and considering Commercial plantings are grown as hedgerows, with the ecological causes of pest problems and the ecologi­ 1 plants spaced about 1 ⁄2 feet apart in rows 5–6 feet apart. cal consequences of control measures. It is a holistic The plant is moderately tolerant of salt and wind, but approach emphasizing tactics that are practical, effec­ wind can damage the flowers. tive and cost-effective, and safe for humans and the en­ vironment. These tactics include releasing and encour­ Irrigation aging natural predators and parasitoids of pest organ­ Water the entire root zone, and allow the soil to become isms, modifying crop environments, and adjusting cul­ slightly dry between waterings. In most areas, this can tural practices in ways that favor the crop while creat­ be accomplished with moderate irrigation, about 1 inch ing an unfavorable situation for the pest. Often, IPM per week. maximizes the use of non-chemical control practices and decreases reliance on and use of chemical pesticides. 2 OF-29 Pikake CTAHR — Apr. 2002 Other strategies of an IPM program include applying Jasminum species. The symptom is a yellowish mot­ mineral oils, soaps, and plant extracts; using inter-crops, tling on the leaves. There is no known control for this natural predators, barriers, traps, and trap crops; and uti­ disease. Seed collected from infected plants may pro­ lizing strict sanitation practices. duce virused seedlings. Grafting with infected plant When chemical pesticides must be used, we recom­ material will ensure its spread. The disease is probably mend that wettable powder insecticide formulations be also spread by sucking insects. As long as plants are used instead of emulsifiable liquid forms to avoid tox­ otherwise healthy, this disease appears to cause no ap­ icities that may result from the oil derivatives. It is also preciable reduction in flower yield or quality. recommended that a rotation of approved pesticides of different chemical classes be used rather than the con­ Pikake diseases tinuous application of one class of pesticide; this avoids Southern blight (Sclerotium rolfsii): white wefts of myce­ the build-up of pesticide resistance in the pests.