Application of Four Layering Techniques in Flower and Nursery Stock Cultivation

Simple layering is suitable for clump-forming flowering shrubs, such as wintersweet (Chimonanthus praecox), winter jasmine (Jasminum nudiflorum), and jasmine (Jasminum sambac). Select 1-2 year old branches near the ground at the base, first make a cut or a ring of bark removal below a node, then open a groove along the edge of the pot or at the root zone, and bury the branch in the soil to a depth of 10-12 cm. Bend a metal wire into a U shape and press it downward to hold the branch in place to prevent it from springing back. Then cover with soil, leaving the tip exposed above ground, and insert a stick and tie the branch to it for support. This method is mostly carried out in early spring or late autumn. Branches layered in spring are severed in autumn, and those layered in autumn are severed the following spring.

Air layering is suitable for flowering shrubs that do not produce suckers at the base, whose branches are difficult to bend, and which are difficult to root from cuttings, such as Chinese rose (Rosa chinensis), osmanthus (Osmanthus fragrans), and Aglaia odorata. Air layering is carried out in late spring and early summer. Generally, select vigorous 2-year-old branches and make a ring of bark removal or a cut below a node, reaching down to the cambium, with a width 1.5-2 times the branch diameter. After treatment with rooting hormone, about 5 cm below the cut, tie on plastic film, then roll it upward, fill it with moss or soil, and tie the top opening, leaving a small gap for watering and catching rainwater. Afterward, keep the medium moist at all times. By autumn, roots will have formed; then sever and plant in the ground or in a pot. After growing for another 1-2 years, it will bloom for viewing.

Horizontal layering is suitable for flowering shrubs with long or trailing branches, such as climbing roses, English ivy (Hedera helix), and Chinese trumpet creeper (Campsis grandiflora). Bend the stems to lie flat on the soil surface or in a shallow trench, cover with soil, and after rooting, sever from the mother plant and replant separately. You can also make a cut below each node, obtaining many young plants at one time.

Mound layering is suitable for flowering shrubs with many suckers and branches that are difficult to bend, such as bigleaf hydrangea (Hydrangea macrophylla), serissa (Serissa japonica), golden chamaecytisus (Chamaecytisus palmensis), and Japanese quince (Chaenomeles speciosa). Before layering, first cut the bark at the base, then mound soil upward 20-30 cm, and keep the mounded soil moist at all times. After rooting, dig out the soil, sever from the mother plant, and plant separately.

Layering of flowering shrubs is burying the branches of a plant in the soil, using the nutrients of the mother plant to sprout new roots, then severing and cultivating them into new plants. Its characteristic is that it promotes rooting without detaching from the mother plant, giving a high survival rate and easy formation, but the operation is rather troublesome and the propagation quantity is small, making it suitable for home use. Layering propagation can be carried out on different types of flowering shrubs according to the methods above.