Guelder rose or common guelder

Guelder rose or common guelder (lat. Vibúrnum ópulus) – a species of medium-height trees or shrubs of the genus Vibúrnum (Vibúrnum) of the family Adoxaceae. It occurs in the forest and forest-steppe zones of almost all of Europe, except the far north, in Western Siberia, Central Asia, North Africa and Asia Minor. A light-loving mesophyte. Lives on average more than 50 years.

A fast-growing shrub or small tree up to 4 m high. Annual increment 40–80 cm. Root system is taproot with numerous lateral branches. Shrub stems are covered with fissured, gray-brown bark. Shoots are rounded, glabrous, ribbed, gray-white or yellowish-brown with a reddish tint. Buds are ovate, with 2 fused scales, pointed, reddish-green. Scales are green or gray, reddish-brown on top, sometimes sticky, glabrous. Sterile shoots end with one bud, fruiting shoots with 2, between which the tip of the shoot is visible.

Leaves large (5–8 cm), broadly ovate, 3–5-lobed, petiolate, opposite, glabrous, wrinkled; light green in spring, green in summer, turning reddish tones in autumn.

White flowers of two types in corymbiform inflorescences up to 10 cm in diameter: small bisexual flowers are located in the center; sterile flowers with large snow-white corollas are located on the periphery of the inflorescence. Sterile flowers open 3–5 days earlier than the fertile ones, decorating the plant for 10–15 days. Flowers in June–July.

Fruits are juicy red drupes of round or elliptical shape, with yellow flesh, red juice and a flat large stone, edible, striking against the foliage.

Has a number of ornamental forms:

'Нанум' ('Nanum') - a compact dwarf form (about 1 m high) with small leaves, flowering abundantly. Vegetates from mid-April to early October. Growth rate slow. Does not flower. Partially frosts in winter. Rooting of summer cuttings 100%.

'Розеум' ('Roseum') - the most common, often called "Boule de Neige" or "Snowball." The cultivar was obtained in France by breeder Lemoine. Shrub height - 2.5 m, small trees - about 4 m. Crown broadly spreading. In Moscow, 50-year-old plants reach heights of 5–6.3 m, crown diameter 3.8–4.6 m. Spherical inflorescences consist exclusively of sterile flowers, first greenish, then bright white, resembling a snowball. As they fade the flowers become pink. During the flowering period, lasting 25–35 days, the plants are highly ornamental both in group and solitary plantings. They are especially effective near water and as standard trained trees. Growth rate medium. Blooms abundantly in June–early July for 18–20 days. Flowers sterile. Partially frosts in winter. Rooting of spring and summer cuttings up to 100%.

'Компактум' ('Compactum'), shrub height 1–1.5 m, crown diameter up to 2 m. In Moscow 7-year-old plants reach 1.5–2 m in height. Crown diameter 1.4–1.6 m. Flowers in late May - June. Flowers fragrant, marginal ones white and sterile, central ones small, bisexual, white or pinkish. Fruits bright red. At 5 years height 0.8 m, crown diameter 80 cm. Vegetates from mid–late April to the end of September. Growth rate slow. Flowers and fruits abundantly from 4–5 years. Blooms in late May–first half of June for about 2 weeks. Fruits ripen in the first half of September. Fully winter-hardy.

'Ауреум' ('Aureum'). A compact shrub 1–2 m high. Leaves bright yellow, then in summer become pale green. Flowers white. Fruits very attractively red. Shows best in light partial shade, especially in hot sunny summers. Can grow in shade but loses its golden color. May suffer some frost damage.

Location: shade-tolerant. Prefers rich, sufficiently moist soils; achieves best growth and ornamental value in open sunny locations. Unlike most species of the genus, tolerates urban conditions well.

Planting: guelder rose can be planted in spring and autumn. Planting hole size 40x50 cm. Distance between shrubs – at least 3 m. Soil mix consists of topsoil from the hole, peat, humus and fertilizers – 3 tablespoons of urea and 1 cup of wood ash or dolomite flour. Ash must be added so that roots do not touch it.

A seedling with a container-grown root system should be placed in the center of the hole and covered with soil. The root collar should be buried no more than 5 cm in the soil. A bare-root seedling is laid on a mound of soil mix and the roots are spread over the mound and covered with soil. After planting it is recommended to make a basin around the trunk circle and water.

Diseases and pests: Diseases: powdery mildew, black and brown leaf spots. Pests: viburnum leaf beetle, black viburnum leaf-rolling aphid, caterpillar of the lilac hawk-moth, barberry flower moth, viburnum and honeysuckle gall midges, green-lobed geometer moth.

Care: consists of loosening the soil, removing weeds, regular watering and feeding. It is recommended annually to apply 2 buckets of well-rotted manure or compost under the shrub. Mineral fertilization is carried out in early spring and before flowering (ammonium nitrate 25–30 g, potassium salt 10–25 g, simple superphosphate 40–50 g, double superphosphate 15–25 g, complex fertilizer 65–75 g per 1 bucket of water for watering 1 guelder rose bush).

Pruning: for guelder rose is carried out in spring before the start of flowering. Sanitary pruning removes all dry, diseased and damaged branches. Rejuvenation pruning is performed no more often than once every 5–7 years. Old branches are cut back to where basal shoots appear, leaving 20–25 cm of large shoots (such pruning can be done in winter and until the beginning of April). With weakened flowering it is recommended to cut the shrub "to the stump" to a height of 15–30 cm from the root collar. After such pruning strong young shoots develop. To encourage abundant flowering, strongly growing shoots are pinched.

Propagation: propagated by cuttings, layering, division of the bush and by seeds. Cuttings are prepared during flowering; green shoots are cut into pieces of 2–3 nodes, 7–10 cm long. Make an oblique cut at the bottom and remove the leaves. Cuts should be smooth. Plant in a cold frame to a depth of 1–2 cm. As a substrate use coarse river sand and peat in a 1:1 ratio. The cold frame is covered with film. Rooting occurs after 3 weeks at +27–+30 degrees Celsius at 70% humidity. For winter the cuttings are covered with leaves and left in the greenhouse until spring.

Uses: The bark and fruits are used in medicine. Fruits are used fresh and dried for making jams, infusions, decoctions, juices, wine, marmalade, vinegar. Bark and fruits contain coloring substances used for dyeing wool. A nectar-producing (honey) plant. Seeds can be used as a coffee substitute. In landscape design the plant is used in solitary and group plantings, hedges. Harmonizes surprisingly well planted with oak, lime and rowan. Valued as a soil-protecting plant.