Perfumed Plants

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purple flowers

A Jacaranda tree in full bloom.

Don looked at some of the plants that produce their perfume through the summer months. Perfume adds atmosphere and a wonderful feeling of romance to any garden. The next time you visit your local nursery, think about buying some fragrant plants.

STAR JASMINE (Trachelospermum jasminoides) is an evergreen twiner with thick glossy green leaves and beautifully perfumed, starry white flowers in late spring and summer. It is moderately vigorous, but it’s not a true jasmine so it will not strangle other plants in the garden. It can be grown in a pot or in the ground, and will flower in both sun and semi-shade.

MURRAYA (Murraya paniculata) is an evergreen shrub to around 3m (10′) tall. The flowers are produced in abundance in spring then again in late summer or early autumn, but they also tend to appear after heavy rain. The plant has a dense, twiggy habit and glossy, dark green foliage, and makes an excellent privacy screen or hedge. Murrayas grow best in warm climates from Sydney to Perth and areas north. It is best to choose nursery plants grown from cuttings rather than from seed, as cutting-grown plants do not have the weed potential of seed-grown plants. People living in cool climates (Melbourne and south) should consider planting the frost hardy choisya (Choisya ternata) instead of murraya. Choisya is a similar looking plant, which also has white, fragrant flowers.

GARDENIAS are attractive, low maintenance shrubs with large, creamy white flowers and glossy green leaves. The flowers have an exquisite perfume that pervades surrounding areas and creates a magical, romantic atmosphere in the garden. Gardenias are warm climate plants, which are at their best in a mild, humid climate. Gardenia augusta ‘Florida’ is one of the best gardenias available. It grows to about 1m x 1m (3’x3′) and produces masses of perfumed flowers on a hardy plant.

ROSES (Rosa sp.) Roses are a must in any perfumed garden. Don mentioned fragrant varieties such as ‘Blue Moon’, ‘Double Delight’ and ‘Papa Meilland’, but there are hundreds of others to choose from. Roses are sold bare rooted in winter, but are available all year in pots. Frangipanis (known by their botanic name Plumeria in America) bring a heady, romantic fragrance to the garden, as well as a wide choice of warm, tropical colours.

FRANGIPANIS. In Australia, frangipanis are sold by colour, rather than variety, and the further north you go, the wider the colour choice. Frangipani was the name of an Italian perfume used to scent gloves in the 16th century and named after its creator, the Marquis Frangipani. When the frangipani flower was discovered its natural perfume reminded people of the scented gloves, and so the flower was called frangipani. The genus name, Plumeria, commemorates Charles Plumier, a seventeenth century French botanist.

Plumeria rubra Native to Central America, Mexico and Venezuela, this deciduous tree grows from 5-8m tall (15-24′). The leaves are dark green and shiny, and have a prominent midrib. Like all plumeria, the stems and leaves contain a white, milky sap. There are at least four distinct forms of this species: acutifolia – white flowers with yellow centres lutea – yellow flowers sometimes flushed pink rubra – deep pink flowers with yellow centres tricolor – white flowers with yellow centres and a red or pink tips

Many of the forms of Plumeria rubra are grown in Australian gardens but the most commonly seen is Plumeria rubra f. acutifolia. Named cultivars are less readily available. Frangipanis will grow and flower well as far south as Sydney and Perth, particularly in coastal gardens. In colder or inland areas grow them against a warm masonry wall, in a north facing position and protect them from frost.

Frangipani rust There is a new disease attacking frangipanis in Australia called frangipani or plumeria rust (Coleosporium domingense syn C. plumeriae). It is most noticeable in late summer and early autumn. Small yellow pustules appear on the underside of leaves. They rupture and spread spores which pass the disease to other plants nearby. The upper sides of the leaves are brown and discoloured. Severe infections may cause the leaves to drop prematurely.

To control frangipani rust try using a fungicide (such as Mancozeb) in the warmer months to slow the development of the disease. Disposing of all fallen leaves in winter and spraying the tree and the area under the tree with a fungicide may slow the reappearance of frangipani rust next season.

OTHER GREAT SUMMER PERFUMED PLANTS:

Heliotrope or cherry pie (Heliotropium arborescens) is an evergreen shrub growing to around 1m (3′) tall and 1.5m (5′) wide. From early spring to late summer it produces clusters of violet to mauve flowers with a heady, vanilla fragrance. Heliotrope grows best in the warmer parts of Australia.

Lavender (Lavandula sp.)There are around 25 species of lavender. They grow to around 1m (3′) tall and most have attractive, grey-green foliage and spikes of mauve/purple flowers. These aromatic shrubs grow best in the cooler areas of Australia. Cost: $17 for 200mm (8″) pots.

Stephanotis or Madagascar jasmine (Stephanotis floribunda) is an evergreen, twining climber with an open habit, which grows to about 2-3 metres or 6-10 feet. The waxy, white tubular flowers are perfumed and are produced from November to April. Stephanotis grows best in tropical climates such as Cairns. If grown south of Brisbane, it needs to be planted in a very hot, sunny spot, perhaps on a trellis against a brick wall.

Peppermint scented geranium (Pelargonium tomentosum) This sprawling plant has pale green leaves, which produce a refreshing peppermint smell when crushed. It tolerates sun or shade and is easy to grow.

JACARANDAS

Australian streets are awash with the magnicient purple-blue blooms of jacarandas (Jacaranda mimosifolia) in late spring and early summer. As well as being superb street trees, jacarandas look stunning on their own as a specimen tree in an open lawn, where their fallen flowers form a colourful carpet of blue.

Lots of people think jacarandas are natives, but they’re not. They are native to Brazil, where they are deciduous, not because of cold winters, but because of the monsoonal wet and dry seasons. They briefly drop their leaves at the end of the dry season, then leaf up again when the rains come.

These trees can reach a height of around 10-15m, and a spread of the same size, so you need to be careful where you plant them, as they can extend a long way. One big mistake some people make is to let a jacaranda overhang their swimming pool, where the fallen flowers rapidly clog up the pool’s filter. However, planted in the right spot, a jacaranda is a magnificent shade tree.

While the most common flower colour for jacarandas is the lovely purple-blue, there is a white-flowered form called ‘White Christmas’, but it is much harder to find this one at nurseries, and you’ll probably need to get it ordered in for you. For the most reliable blue colour, and faster flowering, look for a modern grafted form. Jacarandas are readily available at nurseries in tropical and warm temperate zones.

Growing tips

Jacarandas thrive in tropical and warm temperate climates, but they can be grown in cooler areas which get light frosts, but they usually don’t flower as well in these cooler zones, and they are also slower-growing, and smaller there.

Jacarandas like a sunny position and well-drained, fertile soil, plus regular summer watering. Mulching around the roots with organic material (eg, compost, straw, bark, etc) will help to retain soil moisture in summer, but only apply the mulch over moist ground, not over dry ground, otherwise the mulch might prevent rain reaching the soil. A thickness of no more than 50mm of mulch is recommended.

While jacarandas can be grown from seed, their flower colour varies more and they take longer to flower, but as seedlings often pop up around the base of trees, transplanting them is worth a try and doesn’t cost a cent.

Don’t prune them!

Forget about pruning jacarandas altogether or you will spoil their good looks, and the tree’s shape, forever. When you prune a jacaranda it then sends up vertical shoots (you’ll often see the effect on jacaranda street trees which have been pruned to make room for overhead powerlines). The normal shape for a jacaranda is that of an elegant umbrella, and the appearance of vertical branches ruins its good looks. Your only solution, if you have pruned a jacaranda, is to persist in cutting off the vertical shoots.