The plumeria tree (scientific name: Plumeria; Latin scientific name: Plumeria rubra L. 'Acutifolia') is a deciduous small tree of the genus Plumeria in the family Apocynaceae, about 5 m tall, up to 8 m at most, with a diameter at breast height of 15-20 cm; the branches are thick and stout, somewhat fleshy, with abundant milky sap, green, and hairless. The leaves are thickly papery, oblong-oblanceolate or oblong-elliptic. The flowering period is from May to October, and it rarely fruits when cultivated, generally from July to December.
Growing Environment
It likes a high-temperature, high-humidity, sunny environment with good drainage. It is robust by nature and tolerant of drought, but afraid of cold and waterlogging; it likes acidic soil but is also resistant to alkalinity. For cultivation, deep, fertile, well-aerated acidic sandy loam rich in organic matter is best. The suitable growth temperature is 23°C to 30°C; in summer it can withstand extreme high temperatures of 40°C. When the temperature falls below 15°C, the plant begins to shed its leaves and enter dormancy, until around April of the following year. When cultivated in temperate zones, it tends to shed its leaves in winter. In southern China it can be planted in the ground or in pots, while in the Yangtze River basin and areas north of it, it can only be potted, at 80 cm to 150 cm tall, and it gives off a delicate fragrance when in bloom.
Cultivation Techniques
Plumeria likes a hot and humid climate, tolerates drought, and prefers to grow in limestone rocky ground; it is very easy to propagate by cuttings. Generally, in mid-to-late May, cut branches 20-30 cm long from the base of the branches. White milky sap will flow from the cut, so it needs to be placed in a cool, ventilated place for 2-3 days so that the wound forms a protective film before cuttings are taken; cuttings with milky sap rot easily. Insert into clean vermiculite or a sand bed or a shallow sand pot, then spray with water, and place indoors or under an outdoor shade shed, spraying water once every other day to keep the medium moist. After 15-20 days, move to a semi-shaded place to receive weak light; roots form in 30-35 days, and they can be potted in 45 days. After the small cuttings have rooted and survived, transplant them promptly into pots with a diameter of 20 cm. Plumeria is not strict about soil and is best planted in loose soil containing more humus. When planting, the roots may be slightly exposed when potting; after planting, place indoors, expose to weak light after 1 week, and after another half month it can be placed in a sunny spot. Plumeria grows rapidly and needs to be repotted once every spring, generally into a flowerpot with a diameter of 30 cm. The potting soil can be mixed with 4 parts garden soil, 4 parts horse manure soil, and 2 parts river sand, and 100 g of cake fertilizer or sauce residue and 50 g of superphosphate or bone meal should also be added to each pot. After repotting, water thoroughly, and move it outdoors to a sunny place around Grain Rain.
Plumeria likes a warm, humid, sunny growing environment. In summer, no shading is needed, and it can be placed outdoors in full sun. Summer and autumn are the periods when plumeria grows and blooms. Water 1-2 times every evening; when it rains in summer and autumn, promptly pour out any accumulated water in the pot. From June to November, apply decomposed liquid fertilizer once about every 10 days at a concentration of 15%. In the south, plumeria is planted in the open ground, sheds its leaves in winter, and grows new leaves again the following spring. In the north, potted plants should be moved indoors to a south-facing window in mid-to-late October, taking care to provide ventilation and light. The room temperature should be above 10°C; low temperatures and poor indoor ventilation will cause the plant to shed its leaves. When indoors, water once every two weeks.
Potting Soil
For potted plumeria, it is best to use a porous clay pot; if using a plastic pot, place a layer of broken bricks and tiles or broken hard plastic foam blocks at the bottom to enhance air permeability and drainage. Its root system is relatively developed and it grows quickly. Small seedlings can be planted in a medium pot with an inner diameter of 20 cm, and as the plant grows, it can be moved into a pot one size larger. It is not very strict about soil, and grows best in loose, fertile sandy loam. For home potting, mix leaf mold and garden topsoil in equal amounts, then add a small amount of sand. Repot and change the soil once every year before spring sprouting.
Water and Fertilizer
Plumeria likes humidity and is also drought-tolerant, but fears waterlogging. Therefore, watering should be moderate, following the principle of not watering until dry, watering as soon as it dries, watering thoroughly when watering, and not allowing waterlogging. In spring and autumn, water once every 1 to 2 days when the soil is dry. On sunny days in summer, water once every morning, and in the evening water again if the soil is dry. In the rainy season, be careful to pour out accumulated water in the pot to prevent root rot. In winter, water once every ten days to half a month, keeping the potting soil slightly moist but not dry. It likes fertilizer. When potting or repotting and changing soil, add 20 g to 30 g of bone meal and 50 g to 80 g of superphosphate to the growing medium (because it likes to grow in calcareous soil, pay attention to calcium supplementation). From May to October, apply a light, decomposed organic fertilizer or nitrogen-phosphorus-potassium compound fertilizer once every 10 to 15 days. Do not apply nitrogen fertilizer alone, to prevent excessive vegetative growth. Do not fertilize in winter.
Light and Temperature
Plumeria is a strongly sun-loving flower. The more sunlight there is, the more luxuriant its growth and the more numerous and fragrant its flowers. Except for the 7 to 10 days of shading needed after potting or repotting and changing soil, it should be placed in a sunny place at all other times. Because it is native to the tropical regions of the Americas, it is not cold-tolerant. Shedding leaves in winter when cultivated in temperate zones is a sign of its poor cold tolerance, so it should be brought indoors to overwinter. Move it indoors before the minimum temperature drops to 10°C and place it in a sunny spot, keeping the room temperature at 10°C to 15°C. Keeping it away from TV radiation and air-conditioning warm air can prevent leaf drop, but if it is below 8°C or ventilation is poor, it will also drop leaves. As long as it stays above 5°C, it will not freeze to death, and it will sprout and grow leaves the following spring.
Propagation
Plumeria grown in temperate zones generally does not set seed, so cuttings are used for propagation. From late May to early June, cut branches about 20 cm long from the branching points as cuttings. White milky sap will flow from the cut. If they are inserted without treatment, the cuttings rot easily. They can be placed in a well-ventilated, cool place for 2 to 3 days until a protective layer forms at the wound before inserting, or the wound can be dipped in plant ash or sulfur powder, and after it dries slightly, inserted into vermiculite or a plain sand pot and placed in a well-ventilated shaded area. Mist the cuttings frequently to keep them moist. After 20 days, move them to a semi-shaded place where they can receive sun in the morning or evening. They can root in 30 to 40 days, with a high survival rate, and can be potted in autumn or the following spring.
① It likes light and is slightly shade-tolerant, not cold-tolerant, and extensive in management, but its branches are brittle and break easily. Therefore, choose sandy loam with good drainage, facing the sun and sheltered from the wind, and fertile soil.
② After planting, water thoroughly and place in a sunny spot for cultivation and care, so as to promote flower buds.
③ During the growing season, keep the potting soil moist; in winter, pay attention to controlling water; in summer, spray water on the branches and leaves.
④ After the weather warms up in spring, apply compound fertilizer once every 10~15 days until flowering.
⑤ Before the beginning of winter, move it indoors to a sunny place. The room temperature should be kept above 5°C, so that it can overwinter safely.
