Evergreen boxwood

Synonyms: Buxus angustifolia Mill., Buxus arborescens Mill., Buxus argentea Steud., Buxus aurea Steud., Buxus caucasica K.Koch, Buxus colchica Pojark., Buxus crispa K.Koch, Buxus cucullata K.Koch, Buxus elegantissima K.Koch, Buxus fruticosa Borkh., Buxus handsworthii K.Koch, Buxus macrophylla Dippel, nom. illeg., Buxus marginata Steud., Buxus mucronata Baill., Buxus myrtifolia Lam., Buxus rosmarinifolia Baill., Buxus salicifolia K.Koch, Buxus suffruticosa Mill., Buxus tenuifolia Baill., Buxus variegata Steud., Buxus vulgaris Bubani, boxwood.

Evergreen boxwood (Búxus sempervírens) – the most widely cultivated species of evergreen monoecious dicotyledonous plants of the genus Buxus of the family Buxáceae. Lives up to 500 years. Cultivated since ancient times.

Occurs in Southern and Western Europe, northwestern Africa, and also in Western Asia. The range extends from southern England to northern Morocco; to the east it reaches Turkey and the Western Caucasus. In natural conditions it grows in the understory of deciduous and mixed forests. In regions with humid and warm climates it forms dense groves of trees whose trunks are intertwined with lianas and covered with moss, which retains the necessary moisture and heat.

It appears as a tree (8-15 m), less often as a shrub (1 m). Crown dense, spreading or rounded. Shoots erect, straight, four-angled, green, densely leaved. Bark gray-brown with longitudinal cracks. The wood is very dense, without a distinct heartwood, mature, and highly valued.

Leaves almost sessile, on short petioles, glossy, glabrous on both sides, dark green above, light yellow-green beneath, matte, ovate, obovate-ovate or elliptical, less often narrowly elliptical, 15-23 (25-30) mm long and 5-11 (12-13) mm wide.

Flowers unisexual, small, greenish, with a sharp scent. Staminate flowers are arranged in compact capitate inflorescences; the outer pairs of sepals are concave, almost folded along; the inner sepals 2-2.5 mm long, rounded or obovate in shape, with a rounded, obtuse, less often acute apex. Pistillate flowers are solitary, with 2-7 sepals, 5-6 coverings, sometimes not developing. Stamens are 1.5–2 times longer than the inner sepals. The ovary rudiment is short, 0.75–1.5 mm long and equals 1/3–1/2 the length of the inner sepal. Flowers in March–May.

Fruits ovoid-globose or globose, small, black-brown, three-horned capsules, with individual valves 7-10 mm long and 5-6 cm wide and with horns 1.5-2 mm long, which open as the seeds mature. Seeds small, black.

Forms: tree-like — f. arborescens L. (В. arborescens Mill.), f. angustifolia Loud. (В. angustifolia Mill.) and f. rotundifilia Baill.; variegated — f. argentea Loud. and f. aurea-marginata Loud.; low-growing, almost subshrub forms known only in cultivation — f. suffruticosa L. (В. sufruticosa Mill.) — dwarf small-leaved (almost always sterile) form, low-growing with acute leaves f. myrtifolia Loud. (В. myrtifolia Lam.), or with linear leaves f. rosmarinifolia Baill.; weeping form — f. pendula nummulariifolia hort.

O. W. Tomé "Flora von Deutschland, Österreich und der Schweiz", 1885

Hardiness zone: 5a

Habitat / Site: undemanding; can grow on forest edges, rocky screes, in shrub thickets and dark deciduous forests. Shade-tolerant, warmth-loving. In nature it grows on slightly acidic soils. Most ornamental on calcareous, well-drained, dry fertile loams. Does not like prolonged decreasing air humidity.

Planting: preferably plant in spring so that young plants have time to root and prepare for the cold. Mature trees are transplanted in summer with a root ball. Autumn planting is possible one month before the first frosts. Soil mixture: leaf mold, humus and sand in the ratio 1:2:2.

Care: In hot periods watering is necessary – 1-2 buckets per plant. When young, plants need protection from drying winter winds and the burning spring sun. Boxwoods are most sensitive during long winters with alternating frosts and thaws, and changes between cloudy and bright sunny days. During this period the root system is dormant while the above-ground part becomes active and the leaves do not receive enough moisture. Mulching with peat or well-rotted conifer needles is recommended. When temperatures drop to -10 °C it is advisable to shade the crown – spherical forms are completely covered with plastic or wooden boxes with ventilation holes; standard (single-stem) forms are tied to supports and wrapped entirely with boughs or non-woven fabric. Hardened trunks can be whitewashed with garden paint. Low hedges and borders are covered with burlap or non-woven fabric in 2-3 layers; to prevent breakage bushes can be tied. With the onset of warm spring weather, coverings can be removed, otherwise plants may rot. Remaining snow should be brushed off and removed from around the plant to warm the soil faster. Coverings should be removed in cloudy weather, leaving one layer of non-woven fabric or a small amount of boughs. After 7-10 days the plant can be completely freed from the covering.

Pruning: tolerates clipping and pruning well. Trimming is carried out several times per season; if necessary, it can be trimmed at any time of year.

Propagation: in nature it reproduces vegetatively and by seed. In cultivation it is propagated by summer and autumn cuttings. The seed method is practically not used because seeds have a very long dormancy period. For seed propagation, seeds are sown immediately after collection, in July-August. Summer cuttings are taken immediately after woodening at the base – late June – early July. Autumn cuttings are taken in late August – early September, 5-10 cm long (2-3 internodes). Cuttings are planted in a loose substrate of peat and garden soil in a 1:1 ratio and covered with jars or film. With regular watering, cuttings root in the 3rd week. After that young plants are planted in a nursery bed for growing on at a spacing of 10x10 cm. Rooting percentage of cuttings depending on the species is 80-100%. By autumn, small bushes form ready for transplanting to a permanent place. Layering can also be used for propagation: on young shoots growing near the surface make an oblique cut and insert a small stone there. Bend the shoot to the ground and fix it with staples. Shoots tips should be tied to pegs so that the layers grow upward.

Diseases and pests: resistant to diseases and pests.

Uses: in ornamental horticulture 7 species are used. They are used in solitary and group plantings, to create freely growing or clipped hedges and borders, compositions, for growing in tubs or containers. Also widely used in topiary art. Valued for the dense attractive crown, glossy foliage, and good tolerance of clipping. Catholics decorate their homes with boxwood branches on Palm Sunday. A good nectar plant (honey is poisonous).