Detailed Explanation of Boxwood Cultivation and Management Techniques

Propagation methods: use seed sowing and cuttings propagation.

Seeds generally mature in October. Boxwood seeds undergo a vernalization stage and have the characteristic of germinating in alternate years, so after collection the seeds should be buried in relatively moist sand, and in the following spring the seeds are dug out and sown in sandy soil. After the seeds mature and are collected, dry them in the shade; after the fruit shells crack, the seeds come out, remove impurities and store dry, then sow in winter or spring. After sowing, be sure not to cover with too thick a layer of soil; after covering, press down appropriately so that the seeds and soil can closely combine, which helps the seeds absorb water and promotes germination, and keep the seedbed moist. In March of the following spring, change the bed and transplant, increasing the plant and row spacing. Growth at the seedling stage is extremely slow; after transplanting, the plants still need to remain in the bed for 3-4 years of cultivation, and are then released from the nursery according to the specifications required for greening.

Cuttings propagation can be carried out at any time, but using tender branches grown in the current year as cuttings in summer gives a high survival rate. Use sandy soil as the cutting substrate, take semi-ripened branches as cuttings, 10-12 cm long, with a heel, keeping about 10 leaves, trim the base of the cutting flat, and insert it obliquely into the cutting bed to facilitate air and light penetration, inserting 1/2-2/3 into the soil, press firmly after insertion, water thoroughly, and build a frame over the cutting bed for shade to prevent direct sunlight; frequently spray water to keep it moist. The small seedlings from cuttings in the current year have poorly developed root systems and are susceptible to freezing damage; in winter they can be covered with weeds or plastic film to protect them through the winter. After remaining in the bed for 1 year, plant them separately.

Seedling transplanting and field planting are mostly carried out in winter and spring, and must be done with native soil. If planted as a hedge, increase the density so it takes shape earlier. If large material is needed, shaping and training should be carried out. Boxwood is extremely tolerant of shaping and pruning; if not pruned, there are few branches and the crown diameter is small, but pruning should be timed properly. After boxwood is planted, attention should be paid to pruning (commonly called pinching), especially for tender buds emerging from the base; after half a year, the branch tips should be cut off, and especially tall single branches can be cut more. It is appropriate to prune two or three times a year. After two years the branches are full, and the height and crown diameter are coordinated. Pruning is best done before sprouting and in autumn after growth has completely stopped; pruning between summer and autumn easily stimulates secondary growth, and in the south where winter temperatures are relatively high, this is a measure that can accelerate shaping; but in the north, if autumn shoots do not develop fully, they are susceptible to freezing damage in winter. For the planting site north of the Yellow River, a wind-sheltered spot should be chosen when planting in the open field, otherwise it is also easily damaged in winter. In dry seasons, water appropriately to avoid drought causing leaf drop at the base. Pest and disease control: common boxwood diseases are brown spot disease, leaf spot disease and defoliation disease, generally occurring frequently in seasons with relatively high temperature and humidity. Control should begin in mid-May, spraying Bordeaux mixture or Thiophanate-methyl, Carbendazim and other solutions on new branches and leaves, with one spray each in June and early July. Aphids occur frequently in late spring and midsummer, and can be controlled by spraying 1500-times dimethoate solution. If urea is added to the above solutions, foliar fertilization can be carried out at the same time. In spring and summer, attention should be paid to fertilizing the roots of boxwood; urea can be scattered at the roots before or after rain, and chemical fertilizers can also be used.