Knowing and Growing Australian wattles
Australian Acacias in Europe
by Wolf-Achim Roland
The Greek already knew more than two thousand years ago that big trees with white spines and shiny yellow flowers grew along the Nile river in Egypt. The timber was used to build ships and houses. In Greek αγκάθι means thorn, leading to the name giving species Acacia nilotica.
The first acacias to reach Europe around 1611 came from the West Indies. They were cultivated in the gardens of Cardinal Odoardo Farnese (1573-1626) in Rome, Italy, hence the species name Acacia indica farnesiana.
The major impact, however, resulted from the introduction of Australian species, which were cultivated in the Royal Botanical Gardens at Kew/London from seeds brought by Captain Cook from his expedition to Oceanea from 1780 on. In 1825 about 100 species had been described. The first acacias reached the Cote d` Azur / France in 1804. Until 1850 another 230 species were described.
Horticulturists tested the various plants for their cold resistance, adaptation to alkaline soils and drought resistance.
Acacias normally do not thrive in Europe. But in Southern Europe the climate is comparable to SE Australia, which permits to grow acacia.
The following will highlight the cycles of importance of Australian acacia in Europe for Perfumery, for Landscaping including plants in greenhouses, for the Cut Flower Trade and - more recently - for the Tourism Industry.
In the old testament ( 2nd. Book Moses Ch. 30, 22-26) God tells Moses to prepare a holy oil made from Myrrh, cinnamon, rose water and Kassia. When the perfumeries in France began to extract an essence from acacia farnesiana, they called it “cassie” and the tree “cassier”. This essence formed the basis of the acacia business. In 1920 about 40.000 kg of acacia flowers were processed in Grasse, the perfume center of Europe. The technique applied was called L`enfleurage, translated: “flowerisation”. Fresh flowers are deposited on a bed of (animal) fat that is fixed on glass. Every day for two to three weeks, the flowers are renewed. After that time the fat has been saturated with the essence of the flower. This material was then used in perfumery, e.g. to perfume leather gloves.
But the cold resistance of A. farnesiana was too low, even in the temperate coastlands of Southern France.
Therefore A. farnesiana was substituted by Acacia dealbata with a frost tolerance of up to minus 12 degrees Celsius for 10 days. The quicksilver fell even below this mark in 1929, 1956, 1970 and 1985 destroying lots of trees in the Grasse area. Trees that were saved from the cold fell victim to the frequent wildfires, which raged especially in 1970, 1985 and 1986. Finally, the manual labour employed in the collection of acacia flowers was too expensive.
Perfume production remains an activity in the area. The old method of extraction in animal fats (macerisation) is no longer allowed for hygienic reasons. Acacia flowers are nowadays processed by extracting them with solvents, which are later evaporated. For this purpose 150-200 tons of wild growing acacia dealbata is harvested by cheap labour when the trees are in full bloom – mostly not coming from the local acacia farmers. As the availability varies, some fresh material may also be imported from Italy. The concrete mixture is then concentrated (double-distilled) and further diluted in alcohol or double-filtered to arrive at the absolute, in which the majority of plant waxes and solvent residues are eliminated.
The flowers still on the young twigs (“fleur-feuille”) are extracted.
www.perfume2000.com states that in the Grasse region 1.200 kg to 1.600 kg of concrete and afterwards 300 to 400 kg of absolute are produced. The price of the absolute is 900 to 1.000 Euros per kg. That results in a max. turnover of 540.000 Euro per year for the “absolute” produced in France.
Most of the perfume raw material needed in the French perfume Industry now comes from countries like India or Egypt. There concrete is produced by three times hexane extraction, followed by a gentle steam-extraction.
But it is in France, where the concrete is transformed into perfume-grade “absolute”. In total, the perfumery in France uses absolute from acacias worth over 1 Mio Euro per year.
The high and mighty from Northern Europe, especially from England found out pretty early how agreeable Mediterranean winters are compared to Northern Europe and started to build villas in Spain or Southern France with big gardens, featuring exotic trees and flowers. Here acacia could not be missed, because of their ornamental value: They are nearly the only plants flowering brightly in mid winter. Botanical gardens, gardens of castles or big villas and, nowadays, the margin of boulevards are often planted with acacia, comprising some 15-20 different Australian species, including hybrids.
In some areas in Europe A. saligna was planted to stabilize coastal dunes. Meanwhile it is considered an invasive plant e.g. in Portugal.
Artists also loved to live in the warm South – and still do. They immortalized the mimosa in their pictures, like Pierre Bonnard with “ L`atelier au Mimosa “.
One of the most beautiful gardens on the Cote d`Azur is the Domaine du Rayol, where there is an Australian section with many acacia species. It also features A. hanburyana, an European hybrid between A. dealbata and A. podalyriifolia, that has phyllodes with a varying number of pinnae pairs attached.
In near-by Bormes-les-Mimosas a gardener has a “National Mimosa collection “ with 180 different species, most of which are for sale http://www.pepinierescavatore.com
It is certainly the greatest collection of acacia in Europe.
In the greenhouses of Europe a lot of acacia are to be found. In the Bot. Garden of Düsseldorf University Acacia glaucoptera tells the visitor of the other side of the world, where plants have phyllodes instead of leaves, but still feature the familiar yellow acacia flowers and the special legumes.
In the BotanicaL Garden of the Bochum University (Germany) there is an acacia collection of 20 species, most of them from Australia and in the Royal Botanical Gardens at Kew, there are more than 30 species in the greenhouses, thanks to the legume specialists working there.
Kew also has an enormous collection of acacias in their herbarium.
Coming back to Southern France and the Mimosas:
The total business for landscaping is only a fraction of the cut flower business.
After the arrival of the train, flowers could be quickly transported from the Mediterranean coast to the big cities in Northern Europe. The cut flower trade started to take off after 1871. Farmers re-planted land with acacia trees, because of the high profit margins. New hybrids were cultivated, and trees were grafted onto stems of A. retinoides to better cope with the alkaline soil of the Cannes area. Different grafting methods are used: At first grafting by approachment, then chip bud grafting. There is also some success with cuttings.
Today the cultivated trees are nearly all hybrids between Acacia dealbata and Acacia baileyana. They are called Mirandole, Rustica, Gaulois etc.. There remain some plantations of A. retinoides var. Imperialis, the Mimosa of 4 Seasons.
The cultivars of Southern France have dark green leaves, which harmonise perfectly with the yellow flower. Harvest is between December to March. It is all very small family business with appr. 200 ha cultivated land. In 2002 the amount harvested was about 600.000 kg, shipped in 200.000 boxes a 3kg, with a turnover of about 3,0 Mio to 4,0 Mio Euros. Flowers are mainly exported to Northern Europe (Netherlands, Germany, Switzerland, Norway), the US, Canada and Japan.
The old method of forcing the flowers to open shortly before they go to the market is not much more in use. To increase durability of the cut flowers, special chemicals have been developed, which are added to the water during the forcing procedure or at the customers end.
In retail (Southern France) a bouquet sells for 3-4 Euro.
The farmers supplement their business by growing different Eucalyptus species as a component for floral displays.
The major enemies of the acacia in the region are
a) frost, which can go below -12 o C, killing trees
b) fires; The eucalyptus, planted between acacia trees, helps as a fire barrier.
c) land development .
The apex of the cut flower cycle has probably been passed. There is competition from Italy and other countries bringing the price down. And the transport of flowers by airplane opens the market for other exotic plants that are brought in from far away countries at all times of the year.
But mankind is inventive. Southern France is a tourist highlight in summer. Acacias, which are called Mimosas in France, are decorating many gardens. They grow along the highways, on steep hills , especially around Grasse, but also along the coast till Toulon. It is remarkable that the Australian acacias adapted to their “new” home by changing their flowering cycle to our European early spring time, now blooming beautifully in January and February, the low tourist season.
Mimosa festivals have a long tradition, but it was only recently that seven cities from Bormes-les-Mimosas to Grasse started marketing in 1999 the Beauty of the Mimosa. They organise parades with carriages decorated solely by mimosa ( where up to 8 tons of Mimosa are used in each parade), with music bands, circus animals, artists of all kind. Miss Mimosa is elected in various places. Bus excursions are offered to the Tanneron area (“Golden Route”). Local handcraft markets and guided walks are organised.
During the bus tour the Acacia plantations and the “forceries” (humid, warm rooms to accelerate blooming) are shown, and people can buy all kind of stuff:
Marketing Acacias to attract tourists is on the upswing.
In Germany and neighbouring Eastern countries like Hungary or Poland, everybody is familiar with acacias: But acacias can survive only in greenhouses in Northern Europe. The mentioned popular trees are Robinias (Robinia pseudoacacia), providing the delicious Acacia honey.