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Barberry Thunberg Cobalt is an ornamental shrub of small, almost dwarf growth, used for landscaping the lower tier. It is used to create low hedges, borders and flower beds. The main feature of the barberry Thunberg Cobalt is the high density and spreading of the bush.
Description of barberry Cobalt
Barberry Thunberg Cobalt was bred in the middle of the last century in Holland. This ornamental plant is quite compact in size, reaching a height of no more than 50 cm. In rare cases, its height reaches large values, however, one of its main characteristics, the density of the bush, is lost, and the Thunberg Cobalt barberry becomes less decorative.
Barberry Thunberg Cobalt is grown exclusively as a dense plant with emerald green foliage. Used as a border shrub. In some cases, the barberry Thunberg Cobalt can be used as a single standing. Often a similar technique is used in the design of low flower beds or rock gardens.
The shoots of the barberry Cobalt are short, they are densely dotted with leaves and small thorns. The leaves of Cobalt stick around the shoots and are located oppositely on them. The length of the leaves can reach up to 2 cm, they are elongated and slightly pointed at the end. As they grow, this sharpening gradually rounds off.
The flowering of barberry Thunberg Cobalt begins in mid-May and lasts about two weeks. The flowers are bell-shaped and pale yellow or lemon in color. Their number is quite large: on one shoot there can be up to 2-3 dozen flowers.
Like most representatives of the Barberry family, Cobalt can change the color of the foliage, depending on the season. From the beginning of spring to mid-autumn, the color of the leaves has an emerald hue, changing with the onset of cold weather to orange-yellow. In the autumn months, Thunberg Cobalt barberry is additionally decorative with bright red berries. Barberry Thunberg Cobalt also has a lot of fruits, since almost all flowers are tied.
With the advent of the first frosts, green leaves that have not had time to change color to orange fall off. A photo of the barberry Cobalt is presented below:
Barberry Thunberg Cobalt has a low growth rate and practically does not need formative pruning, however, it tolerates it well, and its crown can be shaped at the request of the owner.
Barberry Thunberg belongs to winter-hardy and frost-resistant plants.
Planting and caring for barberry Thunberg Cobalt
Caring for the Thunberg Cobalt barberry is simple and does not require any complex skills or abilities. Even inexperienced flower growers can grow this ornamental shrub.
The most important thing in its cultivation is not to allow excessive thickening. However, frequent pruning is also undesirable for the plant. Given the low growth rate of barberry, the formation of the crown of the plant once every 1-2 seasons will be optimal.
Seedling and planting preparation
Despite the fact that the barberry Thunberg Cobalt is unpretentious, it would be best for him to be in a sunny area. It is also allowed to grow in partial shade, but the shade is highly undesirable, in which the growth rate of the shrub will be almost zero.
In addition, only in sunny areas will there be a change in leaf color by the autumn season. A plant in partial shade will most likely have orange foliage in the fall, only along the perimeter of the leaves.
Barberry is undemanding to the soil: it does not care about its fertility or hardness. For faster adaptation of a young plant, preference should be given to light soils with an average or low degree of moisture.
Preliminary preparation of the site for planting involves digging holes with a depth of about 40 cm and a diameter of not more than 50 cm. Soil should be laid at the bottom of the pit, consisting of the following components:
- garden soil – 2 parts;
- humus or compost – 1 part;
- sand – 1 part.
The height of the nutrient soil should be from 1/3 to half the depth of the hole.
It is recommended to lime acidic soils with ash or lime (in the amount of 200 g or 300 g per bush, respectively).
No preliminary preparation of seedlings before planting is required.
Rules of landing
Landing should be carried out either in early autumn or late spring. It is desirable that there are no leaves on the seedlings, but there are at least 3-4 vegetative buds on each of the shoots.
Planting is carried out in such a way that the distance between the bushes is from 50 to 80 cm. In this case, it is desirable to add a complex fertilizer for ornamental plants, consisting of potassium, nitrogen and phosphorus, to the holes on poor soils.
The seedling has a fairly developed root system, which must be carefully laid on a layer of fertile soil previously brought into the hole, straighten the root layers and carefully sprinkle with garden soil.
After that, light compaction of the soil and its watering are carried out.
Watering and top dressing
Watering is done as the soil dries out. At the same time, one should not “fill in” the plant too often – one abundant watering for 1-2 weeks is enough.
The first top dressing is done in the second year after planting the barberry Thunberg Cobalt. In the spring, a nitrogen fertilizer is applied, consisting of 20 g of urea dissolved in 10 liters of water per bush. At the end of the season, the bush is mulched with peat. This procedure is then repeated annually. No other fertilizing is required for barberry.
Trimming
The main pruning that the plant needs is sanitary, it is carried out after wintering. At the same time, diseased, old and dried shoots, as well as shoots growing “inside the bush” are removed as a standard.
Formative pruning is relevant only for plants that act as hedges. They are usually sheared 2 times a season (beginning and end of summer). In other cases, formative pruning is performed no more than once every 1 years.
Preparation for winter
Plants older than 3 years do not need to be prepared for winter, as they are able to endure frosts down to -35 ° C without shelter. Young plants should be wrapped with polyethylene for the winter and sprinkled with a layer of foliage 20-30 cm high. And as soon as the first snow falls, sprinkle with snow on top.
However, in spring, in order to avoid overheating of the plant, it is better to remove this “thermal protection” already at the first thaw.
Reproduction
Barberries reproduce in standard ways:
- division of the bush;
- with the help of cuttings;
- layering;
- offspring;
- seeds.
Unlike most perennials, the Thunberg barberry Cobalt does not tolerate reproduction by dividing the bush very well. Any damage to the rhizome that “goes wrong” will be fatal to the plant. Therefore, one should try to divide the rhizome along the thinnest roots, without touching the main root process.
Methods of division by layering or cuttings are more preferable. On average, in the 5th year of life, the barberry has from 2 to 5 layers, which are perfectly transplanted to a new place and begin to bloom after 1-2 seasons.
Cuttings are made from saplings and grown according to the standard method using very liquid soil. At the same time, it is desirable to treat them with a root formation stimulator, for example, epin.
Growing from seeds is also not a problem, since the seeds have a very good germination. The main thing is that they go through stratification. They do it as follows: the seeds collected in autumn are stored until the beginning of April in the refrigerator at a temperature of no more than + 5 ° C. After that, they are planted without any additional processing in a greenhouse or on open ground.
Diseases and pests
The plant has an increased resistance to many diseases characteristic of ornamental plants, however, there are several types of diseases and pests that can cause serious damage to the Thunberg Cobalt barberry.
The most severe disease threat is powdery mildew. This fungal disease on barberry behaves exactly the same as on any other plant: the symptomatology manifests itself in the form of a powdery coating, first on the lower part of the leaves, then on their entire surface, shoots and flowers.
The fight against powdery mildew is carried out using a sulfur-lime mixture and a solution of colloidal sulfur. In this case, the entire affected plants should be sprayed after 2 days on the third for 20 days until the symptoms of the disease completely disappear. At the same time, as soon as powdery mildew is detected, damaged shoots must be cut to the very root and burned.
The main pest of barberry Cobalt is a highly specialized parasite – barberry aphid. Its behavior is standard for all representatives of aphids: sticking to the leaves and shoots, small insects suck out the juices of the plant, from which it begins to dry out. Detecting barberry aphids is quite problematic, since it is extremely small.
If aphids are found, either spray the affected plants with a solution of laundry soap (30 g of soap per 1 liter of water), or use a tobacco solution – 50 g of shag per 1 liter of water. Spraying is carried out daily until the complete disappearance of pests.
Another nasty pest that can infect barberry is the flower moth. To combat it, insecticides are used (for example, Chlorophos or Decis).
Conclusion
Barberry Thunberg Cobalt, due to its decorative properties, is widely used in the design of gardens, home gardens, parks and flower beds. This is an ideal plant for filling the lower tier in any landscaping. Growing barberry Cobalt is quite simple and can be recommended even for beginner gardeners.
