Acacias are trees and shrubs of different sizes, loved in particular for the beauty of a flowering that lasts over time and for their pleasant scent. Cultivated mimosas belong to the acacia genus. Its name derives from the Greek term “akis”, with the meaning of “sharp point”, which indicated an African species of tree.
Two groups are distinguished between the species: those which have compound and bipinnate leaves and those which have flattened leaf leaves and which take the name of “phyllodes” - and are more transformed branches, not really leaves -.
The most widespread species of acacia is the acacia dealbata, belonging to the Leguminosae family. Its vulgar name is mimosa or acacia of the florists, while in English it is called "Silver Wattle". It is therefore the most common among the mimosa trees, it is native to Tasmania and, in our country, it is found above all in the Riviera gardens of the southern areas. It is an evergreen tree, not rustic, with a rich, thick and sometimes disheveled shape. The plant is of medium size - it can even reach 25 meters in height - and has a trunk that can reach up to 2 meters in height. It is particularly appreciated for the abundant flowering that opens in suggestive colors in the months of March and April, but also earlier, and which gives it a remarkable beauty. The gray-green foliage is also very elegant. Acacia dealbata was historically introduced in European gardens in the early decades of the 1800s: still today it is one of the most requested by florists for the trade of its very particular yellow flowers, which have become a symbol of the celebration of women.
It has elegant and light, bipinnate leaves, around 7-12 centimeters in length. These are made up of 15 or 20 segments, consisting of 30-50 small silvery leaflets resembling feathers. The flowers, which shine as mentioned between March and April, are bright with an intense yellow color, forming abundant panicles - 7 to 10 centimeters long - with a very pleasant scent. The floral racemes are formed by yellow blood cells that bring together many stamens clustered in a spherical way.
Acacia dealbata needs a mixture of heather and sand soil enriched with clay and garden soil. A recommended way for the reproduction of the plant is through root cuttings: place the root cuttings in polythene bags with fungicidal powder, then fill a pot with compost and plant a cutting vertically and the others at a distance of about 3 centimeters. The vase must then be covered with gravel or crushed stone, taking care to remove the excess to the brim. It is important not to water the plants until the roots appear. Finally, proceed by enriching the soil with fertilizer.
Its predilection goes to sheltered positions and in full sun, better if close to walls or walls. It also prefers places with mild winters. Too cold winters can in fact be fatal, even if in some cases the plant revives considerably in the spring season. If the branches and the trunk show various damages due to the frosts, there is the possibility of giving life to new vegetations produced by the base during the following spring. For severe winters, however, mobile protections are required for the tree, with the possibility of taking them off and putting them on depending on the climate. All this is not necessary for its growth in the more temperate areas.
It has excellent resistance to salty winds, but does not particularly like significant air pollution.
His favorite soil is acidic. If the soil is richer it will grow extremely easily, but it grows, albeit more slowly, even in poor soils.
To cultivate this type of acacia, very acidophilic, in more calcareous soils, it is advisable to use as rootstock the acacia called retinoides or semperflorens, widely known also as acacia of the 4 seasons. But be careful not to overlook the fact that the latter plant cannot withstand temperatures below 5 degrees below zero.
A drastic pruning is recommended at the end of the flowering season in order to ensure a rich and abundant flowering in the following season. Since the cut frond, widely used in order to decorate the interior, is destined to wither in a short period of time, it is advisable to quickly pass a flame at the base of the small twigs collected. In this way the latex contained in the fabrics will find it difficult to coagulate and the water will have greater ease in reaching the flower.
After flowering, the flower-bearing twigs can be removed to maintain the most desired shape over time, usually compact.
Other species of the tree are the armed acacia, which differs in the presence of thorns and is suitable for temperate climates. Acacia longifolia, with slightly longer bright yellow leaves, kept within 3 cm long spikes. Finally, the farnesian acacia, more widespread in tropical countries, with deciduous leaves, also equipped with thorns.
The very big kind Acacia , of the family Pulses , includes more than 1200 species of trees native to Australia (mainly), Africa, Asia and South America. Mimosa is an acacia native to Australia. Some species of the genus are Acacia dealbata, Acacia tortilis, Acacia saligna, Acacia truncata, Acacia longifolia, Acacia karoo, Acacia cultriformis, Acacia iteaphylla, Acacia longifolia, Acacia luederitzii, Acacia greggii, Acacia dodonaeifolia, Acacia armata, Acacia paradylona, Acacia melanoxylon.
It is known by the common names Mimosa, Silver Mimosa, French Aromo, Acacia mimosa or Australian Acacia.
I'm fast growing trees (it is best to plant them small) that reach 10 meters in height, although in their natural environment they reach 30 meters. Their leaves they are bipinnate , with small bluish-green leaflets on the upper side and hairs on the underside. They produce some yellow flowers with a strong scent grouped in small glomeruli.
They are used in gardens, in places protected from the wind and in walks and avenues. They are also used in florists as cut flowers.
Mimosa needs to be exposed in full sun and high temperatures it does not tolerate frost but can withstand cold temperatures down to 0 ° C.
The ideal terrain for these trees it would be very well drained soil (with coarse sand), granite and with some organic substance (leaf litter, for example).
It's about plants drought resistant , so that irrigation is not too abundant.
The annual fertilizer of the garden is sufficient for them, unless they are in pots, in which case we apply the fertilizer 3 or 4 times a year.
It's convenient sculpt it to shape it, because it becomes huge and messy. By cutting the branches with flowers, we will decorate the house and fulfill two functions.
These plants are susceptible to attack by scale insects .
Mimosa can be multiplied for seeds and stratification, but it is safer to buy it grown lightly.
The mimosa is originally from Australia (which still considers it a national symbol today). In particular, Acacia dealbata is endemic to temperate and fertile Tasmania.
The subfamily of Mimosaceae (belonging to the Leguminosae family) includes about 450 species of acacias coming mostly from the tropical and subtropical regions of Oceania, Asia, Africa and the American continent. They are mostly trees, however those that form beautiful bushes or that have a climbing habit are not rare.
They arrived in Europe at the beginning of the 19th century and spread very quickly, given their adaptability and often very vigorous growth (some can reach 8 meters in height in the first year of life!). They are therefore short-lived plants and are often irreparably ruined by anomalous frosts.
LпїЅacacia dealbata mostly occurs as a tree or shrub. It is characterized by a beautiful persistent foliage: the leaves are bipinnate, up to 12 cm long and formed by 15-20 elements, in turn divided into 30-50 silvery gray leaflets, similar to feathers. The branches can be more or less thorny. The flowers appear at the end of winter (February-April): they are grouped in panicles comprising from 10 to 200 globular and soft flower heads, with yellow-golden or white stamens, very fragrant. The fruits are collected in pods which ripen from mid-summer to late spring.
It is a fast-growing evergreen tree or shrub growing up to 30 m tall, typically a pioneer species after fire. The leaves are bipinnate, glaucous blue-green to silvery gray, 1–12 cm (occasionally to 17 cm) long and 1–11 cm broad, with 6–30 pairs of pinnae, each fin divided into 10–68 pairs of leaflets the leaflets are 0.7–6 mm long and 0.4–1 mm broad. The flowers are produced in large racemose inflorescences made up of numerous smaller globose bright yellow flowerheads of 13–42 individual flowers. The fruit is a flattened pod 2–11.5 cm long and 6–14 mm broad, containing several seeds.   Trees generally do not live longer than 30 to 40 years, after which in the wild they are succeeded by other species where bushfires are excluded. In moist mountain areas, a white lichen can almost cover the bark, which may contribute to the descriptor "silver". [ citation needed ] The Latin specific epithet dealbata also means "covered in a white powder". 
It has been analyzed as containing less than 0.02% alkaloids.  It is known to contain enanthic (heptanoic) acid, palmic aldehyde, anisic acid, acetic acid, and phenols.  [ unreliable source? ]
Along with other bipinnate wattles, Acacia dealbata is classified in the section Botrycephalae within the subgenus Phyllodineae in the genus Acacia. An analysis of genomic and chloroplast DNA along with morphological characters found that the section is polyphyletic, though the close relationships of many species were unable to be resolved. Acacia dealbata appears to be most closely related to A. mearnsii, A. nanodealbata and A. baileyana. 
Some authorities consider A. dealbata to be a variant of Acacia decurrens. 
Acacia dealbata is widely cultivated as an ornamental plant in warm temperate regions of the world,  and is naturalized in some areas, including Sochi (Black Sea coast of Russia), southwestern Western Australia, southeastern South Australia, Norfolk Island, the Mediterranean region from Portugal to Greece and Morocco to Israel, Yalta (Crimea, Ukraine), California, Madagascar,  southern Africa (South Africa, Zimbabwe), the highlands of southern India,  south-western China and Chile.      It is hardy down to −5 ° C (23 ° F),  but does not survive prolonged frost.  It prefers a sheltered position in full sun, with acid or neutral soil. It has gained the Royal Horticultural Society's Award of Garden Merit.  
The flowers and tip shoots are harvested for use as cut flowers, when it is known by the florist trade as "mimosa" (not to be confused with the genus of plants called Mimosa). In Italy,  Albania, Russia and Georgia the flowers are also frequently given to women on International Women's Day. [ citation needed ] The essence of the flowers, called 'mimosa', or in older texts, 'cassie', is used in perfumes. 
The Ngunnawal people of the ACT used the bark to make coarse rope and string, the resinous sap for glue or to mix with ash to make poultices, the timber for tools, and the seeds to make flour. 
The timber is useful for furniture and indoor work, but has limited uses, mainly in craft furniture and turning. It has a honey color, often with distinctive figures like birdseye and tiger stripes. It has a medium weight (540–720 kg / m 3), and is similar to its close relative blackwood, but of lighter tone without the dark heartwood. [ citation needed ]
The leaves are sometimes used in Indian chutney. 
In South Africa, the species is a Category 1 weed in the Western Cape (requiring eradication) and Category 2 weed (requiring control outside plantation areas) elsewhere.  In New Zealand the Department of Conservation class it as an environmental weed.  In Spain, due to its colonizing potential and constituting a serious threat to native species, habitats or ecosystems, this species has been included in the Spanish Catalog of Invasive Exotic Species, regulated by Royal Decree 630/2013, of 2 of August , being prohibited in Spain, except the Canary Islands and the Balearic Islands, its introduction into the natural environment, possession, transport, traffic and commerce.  In Portugal, the species makes part of the official list of invasive species (along with other Acacia species) .
Synonyms: Racosperma dealbatum (Link) Pedley APNI *
Racosperma dealbatum (Link) Pedley APNI *
Acacia puberula Dehnh. APNI *
Acacia decurrens var. dealbata (Link) F. Muell. ex Maiden APNI *
Acacia decurrens var. mollis Lindl. APNI *
Description: Erect shrub or tree to 30 m high bark smooth, deeply fissured with age, gray, gray-green or brown to almost black branchlets angled towards apices, with ridges, hairy, pruinose.
Leaves bluish gray to silvery or sometimes green petiole 0.1–1.5 cm long, hairy, mostly with a gland at base of first pair of pinnae (sometimes absent) rachis 1–12 cm long (rarely to 17 cm long), hairy, ± circular jugary glands present (sometimes missing from basal pair of pinnae), interjugary glands absent pinnae 6–30 pairs, 0.5–5.5 cm long pinnules 10–68 pairs, ± narrowly oblong to linear, 0.7–6 mm long, 0.4–1 mm wide , hairy mainly on margins and lower surface.
Inflorescences in terminal or axillary panicles or racemes peduncles 2–6 mm long, hairy heads globose, 17–35-flowered, 4–7.5 mm diam., Yellow to bright yellow.
Pods straight to slightly curved, ± flat, often slightly constricted between some or all seeds, 2–11.5 cm long, 6–14 mm wide, thinly leathery, glabrous, usually ± pruinose seeds longitudinal funicle filiform.
Photo T.M. Tame
Photo D. Hardin
Distribution and occurrence: south from Ben Lomond.
Grows usually in dry sclerophyll forest or woodland, on a variety of substrates, often on slopes and creek banks.
NSW subdivisions: NT, CT, ST, NWS, CWS, SWS, SWP
Other Australian states: Vic. Tas. * S.A. * W.A.
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The name alludes to the whitish appearance of the branchlets and foliage. Acacia dealbata may be confused with A. mearnsii which has interjugary glands on the rachis and usually golden-hairy peduncles, and with A. silvestris which has larger pinnules, interjugary glands and appressed hairs. A. dealbata regenerates after fire and often forms fire induced thickets. (T. Tame, Acacias of Southeast Australia, 1992). Reported to hybridise with A. baileyana and other Acacia species. The cultivar A. dealbata 'Kambah Karpet' is a prostrate ground cover. Intermediates between the subspecies occur especially where they intergrade on hillslopes.
In most of Italy the climate forces us to grow our mimosa in pots, as it fears the cold enough, especially the very intense and prolonged frosts in areas with fairly mild winters, it certainly finds a place in the garden, in a sunny place, and fairly sheltered from the wind, which could damage the thinnest branches.
For optimal development it prefers slightly acid soils, it should therefore be buried with universal soil mixed with peat or soil for acidophilic plants if the soil tends to become basic over time, modifying its pH due to the calcareous water of the watering, we will notice that the plant will tend to bloom less and less and the leaves will gradually yellow in this case, if the plant is in a pot, we can repot it with new soil for acidophilic plants, or we can provide a good greening fertilizer.
The ideal soil is also very well drained, these plants fear water stagnation, which can quickly lead to the presence of harmful rot, which ruin the root system.We also remember that mimosas prefer deep and fresh soils, without clay, not very compact.
Watering will be regular, from when the plant has the first buds, until autumn, however, avoiding watering if we notice that the soil is still wet. Let's intensify the watering in summer, when the climate is very hot and dry. Especially for plants grown in pots, we avoid that the soil remains completely without water for long periods of time, in fact the mimosas do not tolerate prolonged drought.
These are evergreen plants, which in winter do not have a period of complete vegetative rest, so if we stop watering for the whole bad season, in spring we will easily find ourselves with a dried mimosa so remember to leave our dealbata acacia completely exposed to the elements , which will guarantee sporadic watering even in the middle of winter.
If we live in an area with very harsh winters, and we are forced to shelter the mimosa in a cold greenhouse or in the shelter of a balcony or terrace, starting from autumn, remember to water the plant sporadically even in winter, avoiding however, soaking the soil or watering too often.
As soon as the plant begins to swell the buds, remember to add a slow release granular fertilizer, specific for flowering plants, to the soil at the base. At the end of flowering, remove all the withered flowers and top the outermost ramifications, or those that have been ruined by cold or bad weather.
Citation for this treatment: David Seigler & John E. Ebinger 2012, Acacia dealbata, in Jepson Flora Project (eds.) Jepson and Flora, https://ucjeps.berkeley.edu/eflora/eflora_display.php?tid=11633, accessed on April 05, 2021.
Citation for the whole project: Jepson Flora Project (eds.) 2021, Jepson and Flora, https://ucjeps.berkeley.edu/eflora/, accessed on April 05, 2021.
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Duplicates counted once synonyms included.
Video: Acacia dealbata planting UK