Barberry

Family Berberidaceae. Name: derived from the Arabic 'beiberi' - with petals shaped like a shell

Description: Barberries are mainly distributed in the mountainous regions of the Northern Hemisphere. The genus includes 175 species. Deciduous or evergreen spiny shrubs with simple, alternate, sometimes leathery leaves. Thorns are modified leaves, from which sometimes only the midrib remains, turned into a spine (sometimes three-forked). In the axil of such a “leaf” very short shoots develop, so the leaves sit in clusters. On current-year shoots the leaves are borne singly, spirally. Flowers are small, golden-yellow, fragrant, mostly in numerous racemose or corymb-like inflorescences. Fruits vary in shape and color.

Most barberries are highly decorative and are used in single or group plantings, hedges, and low-growing species on rockeries and as borders.

The coloration of cultivar barberry leaves is incredibly diverse and not only green. It can be yellow, purple, variegated (for example, green with bright white spots in the cultivar "Kelleris" or purple with white, pink and gray spots in the cultivar "Harlequin"), or edged (purple with a thin golden edge in the cultivar "Golden Ring"). Moreover, among barberries there are giants and dwarfs; it is easy to find a shrub of any height from 30 centimeters to three meters.

Barberries are valued not only as ornamental-leaved plants, they also bloom extraordinarily beautifully. Small flowers, resembling spherical bells, either singly or in inflorescences, literally cover the branches from mid-May. Their color is usually yellow, sometimes orange with reddish tones. In hot weather the flowers emit a sweet, tart fragrance. Each petal bears two nectaries that exude clearly visible transparent drops, attracting insects. Barberries flower and fruit abundantly not only in the sun but also in partial shade. Barberry is an excellent nectar source. Alongside linden, buckwheat and floral honeys, there is also barberry honey.

They tolerate urban conditions well. Undemanding to soil conditions, drought-resistant, they do not tolerate waterlogging; they develop better in light but also tolerate some shade.

In the garden we pay attention not only to the color of the leaves and the height of the bush, but its shape is also very important. Often this is the main factor in design. Dwarf barberries usually have a compact dense hemispherical crown. Tall barberries are most often spreading shrubs with drooping branches, although there is an interesting group with erect, vertically oriented shoots, for example the green-leaved "Erecta" and the purple-leaved "Red Pilar". You can shape a barberry to any form and size by pruning. They prune perfectly and make excellent shapes, for example spherical forms. Don’t be afraid to prune; it is very interesting and can be done almost any time of year.

The autumn color of barberries is charming, especially for green-leaved types, whose leaves become orange-purple, while purple-leaved barberries turn scarlet in autumn and are also attractive; yellow-leaved ones practically do not change in autumn. After leaf fall the shrubs are adorned with scarlet berries that remain long into the spring. Birds do not eat them, although they are not poisonous.

In a contest for the best shrub for a spiny hedge, barberry would surely take first place. A barberry hedge can be designed as a free, untrimmed hedge, in which case it will be flowering and fruiting, or as a shaped, clipped hedge. This hedge can be green, purple, yellow or a combination of these colors, which is very effective. With imagination and a good knowledge of the plant assortment, one can design extraordinarily interesting barberry hedges, for example with varied heights, topiary shapes or a combination of clipped and freely growing sections.

There are very few yellow-leaved barberries. The well-known Thunberg's barberry "Aurea" is a cool yellow about a meter tall. It scorches in the sun and requires partial shade. The relatively new yellow cultivar "Bonanza Gold" is not afraid of sun, but it is shorter.

Location: the unpretentiousness of barberries is amazing. They are absolutely undemanding to soils, not afraid of strong wind, tolerate drought well, and only do not tolerate waterlogging. They are all light-loving, but grow well in partial shade, though there are some nuances. To obtain rich purple leaf color, grow them in full sun; plants growing in partial shade show a noticeable green component in their purple leaves.

Planting: for solitary planting keep 1.5 - 2 m between bushes. For a dense single-row hedge plant 4 specimens per meter, for a double-row - 5; for a freely growing hedge, plant barberries at the rate of 2 per meter of length. The shrub tolerates a wide range of soil acidity from acidic to neutral but prefers neutral. Optimal soil pH is 6 - 7.5. Soil mix: garden soil, humus, sand in equal parts (1:1:1). If planting in acidic soil, liming is necessary (300 - 400 g of slaked lime or 200 g of wood ash per bush).

Care: Fertilizers are applied starting from the second year after planting. In spring apply nitrogenous fertilizers (20 - 30 g of urea per bucket of water). Then fertilize once every 3 - 4 years. It is necessary to apply complex fertilizers with trace elements, for example Kemira-Universal. Water once a week. Frequent loosening and weeding are necessary. Mulching is done after planting. Pruning consists of annual removal of weak, poorly developed shoots. Old bushes are thinned in spring. For hedges pruning is carried out in the second year after planting, cutting off 1/2 to 2/3 of the above-ground part. In subsequent years pruning is carried out twice a year: in the first half of June and at the beginning of August. Low-growing barberry forms can be left unpruned; they are well suited for dividing the garden into zones.

Pest and disease control

Barberry aphid: causes leaf curling and drying. In spring spray with a solution of household soap (300 g of soap per 10 l of water) or tobacco solution (0.5 kg of shag tobacco brewed in 10 l of water with dissolved household soap).

The winter moth eats the fruits. When caterpillars appear, treat plants with Decis (0.05 - 0.1%) or chlorophos (0.1 - 0.3%).

Powdery mildew: the causal agent of barberry powdery mildew is a fungus from the genus Microsphaera. This is a highly specialized parasite that infects only barberries. The disease appears as a white powdery coating on both the upper and lower leaf surfaces, as well as on shoots and fruits. The coating consists of mycelium and spores, which continually reinfect young shoots and bushes. By autumn small black fruiting bodies—cleistothecia—form on the mycelium, in which the fungus survives until spring.

Spraying with a 0.5% colloidal sulfur solution, a sulfur-lime mixture or sulfur-lime decoction is used (first at the beginning of leaf bud break, then every 2-3 weeks). Severely affected shoots and leaves are removed and burned.

Rust: when using barberries in rural areas it should be noted that a number of species (common barberry, Siberian barberry and others) are alternate hosts for rust fungi that affect cereal crops. For this reason, growing them near grain fields is unacceptable. In spring bright orange spots appear on the upper side of young leaves, and orange convex cushions of aecia form on the underside, where a huge mass of spores matures and spreads to wild and cultivated cereals. Severe disease development can cause strong leaf drying and drop.

Effective sprays are 1 - 1.5% colloidal sulfur or 1% Bordeaux mixture (first after leaf bud break, then twice at 20-day intervals). Thunberg's barberry is not affected by rust.

Leaf spot diseases are caused by several fungal pathogens. They are all narrowly specialized. Variously shaped and colored spots form on the leaves, which then prematurely dry and drop. This reduces the decorative value of the bushes, disrupts biochemical processes, and shoots do not ripen well, which can lead to winter dieback.

Use copper oxychloride (30-40 g per 10 l), two treatments, before and after flowering.

Barberry wilt appears as leaf wilting and drying of individual shoots, first on one side of the bush and then spreading to the whole plant. Cross-sections of branches show browned rings of vessels. The causal agent is a fungus from the genus Fusarium, and the disease can rightly be called a tracheomycosis wilt, since the infection enters the roots from the soil, causes rot, and then spreads through the vessels to the shoots.

Separately note shoot dieback in which fungal pathogens (more than 14 species described) develop both under the bark and on its surface. In affected bushes leaves wither and fall and individual branches die, but this is not associated with vascular infection and is explained by bark drying. In this case timely pruning of diseased shoots can halt further spread of the disease.

Barberry bacterial disease is caused by bacteria of the genus Pseudomonas. These bacteria cause bacterial canker with characteristic cracks, cankerous growths and proliferation of shoots. At first dark, watery, small (2-5 mm), angular spots form on leaves, petioles and young shoots, which over time acquire a dark purple color. Leaves of all ages are affected and with severe bacterial disease they fall quickly. On branches the spots become elongated, crack, and form brown swellings and outgrowths; the disease does not manifest on flowers and berries.

Winter preparation: Thunberg's barberry "Aurea" and other cultivars are covered for the winter in the first 2 - 3 years with spruce boughs, dry leaves or peat.

Propagation: by division of the bush, root suckers, summer cuttings and seeds.

It is better to sow them in autumn. Freshly collected fruits are pressed, sieved, washed and slightly dried until free-flowing. They can then be sown in furrows at a depth of no more than 1 cm. For spring sowing stratification for 2 to 5 months at 2-5°C is required. Seed germination up to 95%. The soil should be loose and fertile, and the site open and well lit. In early summer uniform seedlings appear. When two true leaves appear thin seedlings, leaving at least 3 cm between them. Seedlings are better grown for two years in one place without transplanting. The first leaves of seedlings differ from subsequent ones by being smaller. Since barberries are easy to grow, both species and ornamental forms can be planted. But cultivar characteristics cannot be guaranteed from seed; for example, if you sow seed of a purple-leaved barberry, offspring will show leaves of varying shades of purple and green.

Barberries are easily propagated by green cuttings, and with a little effort in June you can obtain a large amount of uniform high-quality planting material within a couple of years.

Uses: multifaceted. Primarily clipped and free hedges and borders. For the conditions of central Russia this is the most suitable crop for creating them. Barberries are the best substitute for boxwood, which is unsuitable for our climate. Hedges from these shrubs are impenetrable and prune well, allowing any contours to be given to the bushes. Barberries are used as specimens and in group plantings, in rockeries, and as groundcover. The variety of cultivars gives the gardener virtually unlimited creative possibilities.