Jacaranda mimosifolia

Jacaranda mimosifolia, or Blue Flamboyant, is a magnificent exotic tree, famous for its extraordinary lavender-blue flowering which floods the avenues of many countries with mild winters. Its feathery fern or mimosa foliage, briefly deciduous at the end of winter, is very decorative. Its flowering is enchanting, with large panicles of blue trumpet-shaped flowers. It appears first on the bare wood, at the end of winter, then again from spring until the beginning of summer, sometimes even in autumn. Apart from its lack of hardiness, Jacaranda mimosifolia is not very demanding. It tolerates most soil and is resistant to summer drought once established. A choice subject for a coastal garden. In cold climates, it can be grown in a container and overwintered in a large greenhouse. However, its flowering might be limited in these conditions. 

Jacaranda mimosifolia belongs to the Bignoniaceae family. It is a cousin of campsis, catalpa and Chilopsis linearis, for example. Originating from the high dry meadows of central-south South America, this beautiful ornamental tree has been planted all along the Mediterranean coast, in Japan and Nepal, in South America and also in North America (Texas, Southern California, Mexico), in South Africa and in the Maghreb, as well as in Australia. The Blue Flamboyant is also widely planted in French Guiana, Martinique, Guadeloupe, Reunion Island, and Mayotte. Its hardiness is evaluated at - 7°C (19.4°F) at peak for an adult subject, although some American sources suggest that old subjects have resisted -12°C (10.4°F) (at the end of the night), east of Los Angeles.

In nature, the Blue Flamboyant is a fast-growing tree, with a spread-out habit, which can reach 40m (131ft) in height. In the open ground under our latitudes, it rarely exceeds 12m (39ft) in height and 8 to 10m (26 to 33ft) in width if conditions are optimal. Grown in pots, its dimensions will be much more modest. Its initially smooth grey-brown bark becomes scaly with age. The plant can form several trunks, especially if it is pruned. It is often necessary to train young trees to clear a single trunk. The light red-brown branches are thin, quite brittle, and slightly zigzag. The foliage appears in April-May and falls at the end of winter, in February-March. It consists of large compound leaves measuring up to 45cm (18in) in length. Each one is cut into very small villous leaflets about 1cm (0.4in) long. Their colour is a very bright green. Flowering appears on subjects measuring at least 2m (7ft) in height and sometimes after several years. The flower buds form in autumn or early winter, and will be destroyed as soon as temperatures hit -4°C (24.8°F). The flowers bloom for the first time en masse in March-April, on the bare branches. They are tubular in shape, opening onto 5 short rounded lobes, 5cm (2in) long, and mauve-blue in colour. They are gathered in panicles 20 to 30cm (8 to 12in) wide. This honey-rich flowering can continue until the beginning of July depending on the climate, or else reappear in September-October. It is then less spectacular on the foliage. After pollination by insects, the fruits are formed which are round and woody pods 5 to 7cm (2 to 3in) in diameter whose shape and slightly pearly colour can evoke oysters (hence the common name of oyster tree). Each pod contains numerous flattened and winged seeds.

Particularly adapted to the Mediterranean coast, some beautiful specimens of Jacaranda mimosifolia can be admired on the Var coast, in Corsica or near Perpignan for example, where the mild winters and the humid spring weather allow it to flourish. This fairy-tale tree deserves a place on its own in a large sheltered garden. Consider its size when planting; it should be planted away from walls and care should be taken that its faded flowers do not fall into the neighbour's garden, as they have a reputation for being "messy". The Blue Flamboyant works well alongside large evergreen ceanothus, mimosas, and eucalyptus. Note that its roots are harmful to those of other plants and that violent winds are extremely unfavourable to it because of its brittle wood.