The yellow acacia is a stunted tree or deciduous shrub. The scientific name of this plant is Karagan tree. It is actively used by gardeners and landscapers for landscaping purposes. And this plant also has medicinal properties and is an excellent melliferous plant.
Peculiarities of yellow acacia
The yellow acacia, or Caragana arborescens, is a member of the legume family (Fabaceae).
It has been cultivated since 1752. The crown consists of trunks that are about 15 centimeters in diameter. Special pruning allows you to get a small spectacular tree. The smooth greenish bark has a pale gray cast. This acacia usually does not grow taller than 4 meters, but its crown reaches about 2.
5 meters across. In the same spot the shrub can grow for about 50 years.
The alternate petiolate leaf plates are compound in shape. They are greenish in summer, changing to yellow in fall. The petiole, about 15 centimeters long, has five to eight pairs of shiny, supratellar, oval-shaped leaflets.
There are prickly bracts, which may eventually become woody. The monopolar, moth-like flowers consist of a yellow corolla and a dozen stamens. The flowers are arranged in bunches of 2-5, and they form in the axils of the leaves. The plant blooms in late spring or early summer. Fruits are cylindrical beans that mature in July or August.
Caragan tree / Acacia yellow / Botanical Garden, Kharkov
The yellow acacia is very common in Siberian forests, including the Sayan mountains and the Altai. And it is also found in the southern part of the Ural Mountains and in the eastern and central regions of Kazakhstan. It is also quite often found in the mountains of the Caucasus. Most often the germination of Acacia seeds is observed in the glades, in sparse undergrowth or on not very large slopes. This plant is also often used within the city limits for landscaping parks.
Planning and care
The yellow acacia plant does not have any particular requirements for soil composition. It can often be found near roadsides. In the garden it is used for making green hedges, camouflaging unsightly buildings or strengthening slopes.
To form a green hedge compact planting is used, for this purpose the bushes are planted 0.7-1 meter apart.
After a while the acacia trees grow and close together to form an impassable obstacle. For a proper size hedge, pruning is used.
Transplanting is done:
- in early spring when the soil is loose, but before the buds awaken;
- in autumn after the growing season and leaf fall.
The planting hole should be about half a meter deep and the soil must be acidified by mixing it with peat. The plant planted is not difficult to take care of.
It should be timely watered, pruned for sanitary purposes, remove weeds, treated for preventive purposes against pests and diseases. Annually in the spring time, make an application of compost and mineral complex to the soil of the starter circle. However, nitrogen fertilizers are not used because the shrub does not need nitrogen.
Gardeners can easily propagate yellow acacia by such methods as cuttings, seed and grafting. To make cuttings, use annual shoots that should be semi-timbered.
First, treat the cuttings with a product that stimulates root growth. After that, carry out their planting in the open ground in the first summer weeks. The soil on the plot should be loose. Those cuttings that will give roots, in the autumn time planted in a permanent place.
Soak the seeds before sowing, it should swell.
Sow the seeds in the open soil as soon as it thaws or sow them in the greenhouse for seedlings. Transplanting seedlings from the greenhouse to the open soil is carried out after 1 year in the last spring weeks. Hybrids are propagated by grafting as well as weeping stem forms.
Diseases and pests
Acacia yellow is subject to fungal diseases, namely rust, powdery mildew and white rot. For preventive purposes, experts advise cutting out and destroying all diseased parts of the bush.
Also in the autumn time it is necessary to destroy all the leaves that have fallen off. A plant affected by rust should be treated with copper sulfate or Bordeaux mixture.
Acacia aphids, leaf beetles, false scabs, borers and glassworms are the most common pests that settle on the plant. If there are too many pests, the shrub is sprayed with an insecticide solution.
Use and importance
Since long ago, yellow acacia has been widely used for landscaping parks and gardens.
This shrub has medicinal virtues that are highly valued in both conventional and non-conventional medicine. At the same time use all parts of the plant: bark, leaves and flowers. Its inflorescences have antipyretic, expectorant and anti-inflammatory properties.
Acacia honey also has medicinal properties because it consists of 35 percent glucose and 40 percent fructose. It has a positive effect on the overall health of the body, contributes to strengthening the immune system and normalizing blood glucose levels.
Acacia flowers for only a couple of weeks, but this time is enough for bees to collect a large volume of nectar. It has been noted that when the weather is dry, the flowers produce the greatest amount of honey.
Any part of the acacia plant can be used to make decoctions or infusions to help with heartburn and headaches. The bark and roots are widely used for respiratory ailments, flu, rheumatism and pollinosis. The plant is also used to secrete cytisine.
This substance increases blood pressure, excites the CNS and stimulates the synthesis of adrenaline. This alkaloid is used very widely in anti-nicotine therapy.
The acacia plant possesses wood that is among the core species. They are characterized by whimsical fiber patterns and spectacular textures. The core of the wood is light brown, with its predominant shade being pale yellow.
It also has a very thin sapwood. The wood is very flexible, strong, and hard. The timber shows a strength of 600-630 kilograms per square meter when wet to approximately 12 percent3, which is very similar to that of oak. There are no cracks on the dried wood and there are no signs of warping. One of the important disadvantages of the material is a low biopersistence.
Because of this, it is used only indoors. The wood is very good for processing, including varnishing and polishing.
Most yellow acacia wood is used for making of crockery and souvenirs. Strips are used for making hoops for tubs and barrels. However, this species is not used for furniture as the trunks are not very wide.
Caragan tree or yellow acacia
Use in landscaping
Yellow acacia is very often used in gardening to obtain spectacular green hedges. Seedlings can be planted in single rows or in staggered rows if you want a wide fence, for example, around a field. The root system is well developed and powerful, so the plant is used to protect the soil from crumbling and erosion. In this regard, it is often used to strengthen slopes and ravines.
In city parks and private gardeners, this plant is used not only for landscaping, but also to increase soil nutrition.
Its root system is able to accumulate nitrogen in the soil, which is used by other crops for nutrition. This is why most plants feel great near yellow acacia.