Taking a walk around the streets in your neighbourhood is a great way to discover the plants that grow well in your area. Street trees can also be an important source of shade and provide food and shelter for native wildlife. As well, established street trees give character to the neighbourhood.
In early November, Don Burke took a walk around the streets of Brisbane and discovered the following trees, most in full flower.
Jacarandas, (Jacaranda mimosifolia), are spectacular late spring flowering trees, which create washes of purple through many Australian towns and suburbs each spring. Jacarandas come from Brazil but they grow well in Australia. In particular mass plantings of jacarandas along the street create a river of purple as well as a carpet underneath the trees when the flowers begin to fall. Our segment was filmed at New Farm Park in Brisbane.
Jacarandas are large trees which grow to 10m (30′) tall and up to 10m (30′) wide with a low, broad branching habit. As well as the commonly seen purple, there are also white-flowering and variegated foliage varieties.
Tip: Don recommends never pruning a jacaranda because otherwise new vertical shoots will grow from the pruned branches distorting the natural shape of the tree.
Best climate: Jacarandas do not like frost and grow best from Sydney to Perth and north along the coast. They are well suited to warm coastal areas but will grow inland and further south if protected from frosts for the first couple of years. In colder areas plants may flower later in the season and trees will be smaller in height and spread.
Availability: Jacarandas can be grown from seed but will be slow growing. Seedlings spring up around existing trees and may be transplanted. Alternatively sow seed that is collected after flowering. Jacaranda trees are available from most large nurseries and garden centres, particularly in warm and tropical districts. They cost about $15-$16 for a 20cm (8″) pot and around $50 for a 30cm (12″) pot. Colours other than purple will be harder to obtain and may be more expensive.
There is no commonly used name for the unusually named schizolobium, (Schizolobium parahybum), although it is known in Brazil as the bacurubu and in Brisbane is widely referred to as a yellow jacaranda. It has green, ferny foliage and in spring a profusion of yellow, pea-shaped flowers in spikes 30cm (12″) long. This fast-growing tree originates from Brazil and Mexico and grows to about 40m (130′) tall. It looks much like a cross between a yellow flowering jacaranda and a tree fern as it has ferny leaves and an umbrella shape.
The tree looses its large leaves in spring just before flowering occurs. The leaves, which can be up to 2m (6′) long are supposedly the largest compound leaves in the world.
Best climate: This tropical tree is best suited to areas north of Brisbane, however it can be grown in some of the cooler zones (such as Sydney and Perth) in a warm microclimate.
Availability: These trees are not easy to find at garden centres. Ask your nursery to order the tree for you. Alternatively, each seed pod contains a single seed which can be grown. Young plants grow rapidly. Our segment was filmed in Verney Street, Graceville in Brisbane.
Black bean tree
The black bean tree (Castanospermum australe) is also called the Moreton Bay chestnut. It is a flowering Australian native tree that can grow as tall as 30m (100′) but is usually smaller in cultivation (to around 10m or 30′). The flowers are a bi-colour orangey-red and yellow which are highly bird attracting, especially to Australian native birds such as rainbow lorikeets. The foliage is glossy green and dense. The tree also produces gigantic seed pods which are full of golf ball sized green seeds which can be planted to sprout a temporary indoor plant. The seed pods, which split in half and are buoyant can also be used by children to make little boats or other toys.
Best climate: This semi-tropical rainforest native occurs naturally along the east coast from Port Douglas to the Northern Rivers area of NSW and is common on riversides. It can also be grown in frost-free spots as far south as Melbourne.
Availability: Black bean trees are not readily available from nurseries but try your local native plant nursery. Trees can also be grown readily from the seeds (collect from around a tree in your neighbourhood). In particular seed-grown trees when still young are suitable for indoor plants.
Cock’s comb coral tree
Another bird attracting tree for nectar feeding birds such as the rainbow lorikeet is the cock’s comb coral tree (Erythrina crista-galli), which has stunning red flowers in late spring or early summer. It is small to medium-sized deciduous tree that is sometimes almost shrublike. This shrub-like look is maintained by cutting the tree back in winter to encourage long, shoot-like branches. With age the tree develops a trunk and rounded head and can be 4-6m (12-18′) tall. Some very old specimens can reach 10-5m (30-45′) tall. This tree is native to Brazil. It is not as popular or as large as the common coral tree, (Erythrina x sykesii), which can reach 12-18m tall with a spread of up to 15m wide (36-54′ x 45′). The cock’s comb coral can be grown in most areas of Australia once established. It prefers a sunny position, welldrained light soil. Shelter from wind and plenty of summer water.
Best climate: This semi-tropical tree grows in most areas of Australia with adequate water and care.
Availability: Cock’s comb coral trees are hard to find in nurseries but they are easy to propagate by cutting. Select a branch from an existing tree as a large cutting or grow from seed. Our segment was filmed at Sherwood Arboretum, Jolimont Street, Sherwood, in Brisbane.
The weeping fig (Ficus benjamina) is an excellent tub plant for brightly lit areas indoors, on a balcony or in a sheltered courtyard. Planted out in the garden however it will develop into a very large tree 15m (45′) or more tall and wide with invasive roots. In tropical areas where this tree will grow even larger it can be found with the buttress roots that typify rainforest plants. Rather than plant out a tree that is getting too large for indoors, prune it lightly and repot it into a slightly larger pot.
Best climate: The weeping fig is a tropical plant (Brisbane and north) but it will grow well in most frost-free areas. It is used as an indoor plant in most parts of Australia.
Availability: A pot plant will cost around $20. Although more expensive than the ordinary weeping fig, standard forms of weeping fig are now widely available often with platted or twisted trunks. Expect to pay around $50 for a weeping fig grown as a standard.
For information about street trees in your area contact your local council.