Better known as frangipani, Plumeria rubra is a delightful small tree for a garden with a semi-tropical look, usually reaching a height of around 4 m, though with great age they seem capable of growing to 8-10 m, with a wide, symmetrical canopy. Plumeria belongs to the Apocynaceae family of plants. The frangipani tree has a distinctive domed canopy. Unfurling like miniature parasols from slim buds, the exquisite waxy flowers begin to appear in early summer and continue through autumn, and are strongly perfumed. Many can be seen in inner-city suburbs of Sydney, in the front gardens of terrace houses.
In Sydney, we mainly see the classic creamy coloured version with a lemon centre, but there are many pretty cultivars, including pinks of various tones, peach, pure white, yellows, reds, oranges, cerise and even violet. Some are striped or have petal edges in a contrasting colour, and petal shapes can vary. Some of the exotically coloured cultivars now also have a fragrance. There are various species of Plumeria, but P. rubra is the best for our climate.
The root system of the tree is fairly shallow and not invasive, making it possible for them to be transplanted, with care Originating in Central America, they are frost sensitive but cope well with our Sydney climate. The large elliptical leaves are attractive. Frangipani trees are quite deciduous here, but I find their reindeer-antler look in winter rather endearing, and they cast quaint shadows on sunny days. It is possible to attach epiphytic plants such as orchids and bromeliads to the trunk to provide interest in winter; and the epiphytic orchid cactus (Epiphyllum) can be grown through the branches to give support to its lanky stems.
They need five to six hours of sunlight each day, reasonable soil, and sufficient water in summer - less is required in the cooler months. Shelter from strong winds is advisable. They don't need pruning - which will destroy their attractive natural shape - unless they become very lanky, when cutting back can be done in stages in late winter or early spring. Also, if the centre of the plant becomes congested, it is a good idea to remove this growth, which will improve air circulation. They grow easily from large cuttings taken in early spring - leave the pieces to dry for a few weeks, then push them firmly into pots of propagating mix and place in a shady position. They take a while to strike but should succeed, and can be planted out into the garden the following spring.
Rust may affect the foliage in the humidity of late summer. Remove all affected leaves, place in a plastic bag and dispose of in the regular garbage bin, not the green waste one, and certainly don't compost them. Spray the tops and undersides of the remaining leaves with an eco-friendly fungicide mixed with a horticultural oil to help it stick on. it can be a good idea to spray the ground with the same mixture after you have picked up all the leaves, to destroy spores. Contact with the milky sap of the tree should be avoided. Fertilise frangipanis with an all-purpose fertiliser in spring once the leaves begin to appear. Sulphate of potash can also be applied to enhance flowering. The fertiliser can be applied via holes dug around at the drip line of the tree with a crowbar, so that the food gets to the tree roots rather than the surrounding lawn.
I have seen frangipanis growing in pots quite successfully; these can be repotted in late winter and either root-pruned for planting back into the same pot, or moved on to a larger-sized container.
Frangipani trees play an important role in some religions, with the flowers being used as temple offerings in Buddhism and Hinduism, and the trees often being planted in Islamic cemeteries in Malaysia and Indonesia. In Hawaii, the blooms are made into ceremonial leis for special occasions.
The milky sap can be a skin irritant in sensitive individuals causing rash and blistering. Ingestion of the sap or bark can cause vomiting and diarrhoea.