Detailed Explanation of Osmanthus Tree Cutting Techniques and Methods

Osmanthus tree cutting techniques: cuttings have the advantages of easy material collection, simple operation, saving propagation materials, and a high propagation coefficient, with a survival rate of over 80%.

1. Osmanthus tree cutting bed preparation

The cutting bed should be chosen in a place with higher terrain, good drainage, and close to a water source. The seedbed is 1 m wide, with unlimited length, but generally not more than 20 m. The cutting bed is built up with bricks around the sides, 10-25 cm above ground level. A 10-20 cm thick substrate is laid inside the bed. The substrate can be slightly acidic sandy loam, river sand, peat, etc.

2. Selection of Osmanthus tree cuttings

Cuttings should be selected from 10-15 year old trees, from the middle and upper part of the outer canopy, growing robustly, pest- and disease-free current-year branches, generally about 10 cm in length. The upper end of the cutting retains 1 pair of leaves, and the lower end is cut 0.5 cm below the node, with the cut slightly slanted. Cuttings should be inserted as soon as they are cut to prevent water loss and wilting.

3. Osmanthus tree cutting method and post-insertion management

Water thoroughly once before insertion. Generally, row insertion is mostly used, with 10 cm row spacing and 5 cm plant spacing, inserting 200 plants per sq m. Insertion depth: long cuttings are generally inserted 2/3 deep; short cuttings are inserted entirely, with only the upper buds exposed above the substrate. Water thoroughly immediately after inserting the cuttings so that the cuttings and substrate are relatively firm.

After cutting, build an arched hoop shed above the seedbed, with the shed top 50-60 cm from the bed surface, cover the shed with plastic film, and 1 m above the top of the plastic shed, build another tall shade frame, and hang curtains on the east, south, and west sides to prevent side light exposure.

Keep the light transmittance of the cutting bed at about 30%, control the temperature at about 25°C, and ventilate for 1-2 hours every morning.

30-50 days after cutting, the cuttings will heal and root; after 60 days, the shading time can be reduced, and afterward all shading materials can be removed. The above is the Osmanthus tree cutting technique.

Osmanthus tree cutting techniques

Osmanthus tree cutting techniques: Osmanthus tree cuttings are often taken in spring, the plum rain season, or after early autumn, but the south mostly uses plum rain season cutting, which roots quickly and has a high survival rate. The specific cutting time varies due to local climate and fertilizer and water management. The best cutting time is based on the standard of current-year spring shoots and summer shoots stopping growth and becoming semi-lignified, because at this time the branches have the most complete nutrient storage and their meristematic tissue has strong division ability.

(1) Osmanthus tree cutting bed preparation

It is advisable to choose light loamy cultivated land for deep plowing to make the bed. The bed is required to be 120 cm wide, 25 cm high, and the ditch 40 cm wide, with fine crumbly soil, a flat bed surface, and unobstructed ditches. If there is deep yellow subsoil without weed seeds, it is best to cover the original soil with a 5 cm thick layer of yellow subsoil, which can reduce weeds and disease occurrence. Build two sheds above the cutting bed, one above the other, namely a plastic film shade arch shed 50 cm high from the bed surface and a shade shed 1.8-2 m high from the bed surface, with shading nets of 50% light transmittance.

(2) Osmanthus tree cutting time

It is advisable to carry out from mid-May to mid-June. The specific time is best when the new shoots stop growing.

(3) Osmanthus tree cutting collection

Select vigorous, pest- and disease-free superior plants within 6 years old as mother trees for cutting collection. In the morning, cut current-year semi-lignified young branches from the upper outer part as cuttings.

(4) Osmanthus tree cutting treatment

Cut the cuttings into lengths of about 5 cm, keep 2 opposite leaves on the upper part, and cut off the remaining leaves. If rooting agent is available, it is best to treat them before cutting, as this can shorten the rooting time of the cuttings.

(5) Osmanthus tree cutting operation

Cuttings should be inserted in separate beds (sections) according to diameter class. With a plant and row spacing of 5 cm x 10 cm, insert the cuttings into the soil to a depth of about 2 cm, water the seedbed thoroughly with clean water, then spray the seedbed with a 1000-1500 times carbendazim solution. After disinfecting the soil and cuttings, immediately cover fully with a small arch shed.

(6) Osmanthus tree post-cutting management

When there are no water droplets in the shed film and the bed is dry, spray water in time to maintain moisture. Generally, uncover the film after about half a month for inspection. If humidity is found to be insufficient (relative humidity maintained at 85%), sprinkle water, and after the leaves are slightly dry, spray with 1000 times carbendazim solution to prevent disease. At the same time, combined with spraying, 0.2% urea or potassium dihydrogen phosphate solution can be added to promote root and new shoot growth of the cuttings. If there is rainy weather for more than one consecutive week, remove the lower shade net to increase light transmittance.

After Osmanthus cutting, roots generally form in 1-3 months (Four Seasons Osmanthus roots in 1-1.5 months, Jinyin Dangui roots in 2-3 months). When 80% of the cuttings have rooted, choose a rainy day to remove the lower shade net and plastic film for hardening; if hardening on a sunny day, remove the plastic film at both ends in the morning and evening for ventilation for half a month, then remove the lower shade net and plastic film. By the end of October, new shoots of the seedlings have already grown. According to weather conditions, promptly remove the upper shade shed on a cloudy day or in the evening (generally at Cold Dew), and by the next spring the young seedlings can be transplanted to field nurseries. The above is the Osmanthus tree cutting technique.

Osmanthus cutting techniques

  Summer softwood cutting of Osmanthus is one of the main means of large-scale Osmanthus propagation. It staggers the busy spring seedling raising and afforestation season, and arranges seedling raising in the relatively idle summer, allowing sufficient time for operations, so summer cutting propagation of Osmanthus is highly efficient in production. The cutting propagation techniques are introduced as follows:

  1. Nursery site preparation:
If land is planned for use, it can be deep-dug twice in winter, and a seedbed 20 cm high and 90 cm wide can be prepared for later use. Vacant land left after spring seedling outplanting can also be used for production. Deep plow once, pick out tree roots and other debris; after spring seedling production ends, deep plow again, and similarly prepare a seedbed 20 cm high and 90 cm wide for later use. In early June, remove weeds growing on the seedbed, then disinfect with a 1:100 formaldehyde solution, deep plow once, and make a turtle-back-shaped seedbed slightly higher in the middle and lower on both sides.

  2. Collection and treatment of cutting material:
Summer softwood cutting of Osmanthus is generally carried out from mid-to-late June to early July, when Osmanthus new shoots have stopped growing but are not yet mature, being in a semi-lignified state, and the cells inside the branches divide actively, making rooting and survival easy. Cutting too early means the branches are tender and not easy to survive; cutting too late means cell division inside the branches tends to stop, also making rooting and survival difficult. Cuttings should be collected from mother trees of superior varieties and robust growth; weak branches, inner-canopy branches, and pest- and disease-damaged branches cannot be used as cutting material. It is best to cut cutting material on a sunny morning or on a cloudy day; do not collect on dry days or rainy days. Collected cuttings should be transported back promptly, spread out in a cool place, sprinkled with a small amount of water, and then covered with water-soaked cotton cloth to maintain moisture. Cuttings are generally cut 10 to 15 cm long, with 2 to 3 leaves retained at the top; the lower end of the cutting is cut with a slightly slanted cut, and the cut should be smooth to facilitate insertion and healing and rooting. Align the lower ends of the cut cuttings and tie them in bundles of 30 to 50. Then place the cuttings neatly and vertically in a prepared 100 ppm naphthalene acetic acid solution or ABT rooting powder solution, generally soaking for 6 to 8 hours before removal, rinsing the base with clean water, and then cutting.

  3. Cutting and post-cutting management:
Insert according to a density of 4 to 6 cm plant spacing and 15 to 20 cm row spacing; the insertion depth is generally 1/2 to 2/3 of the cutting length. After insertion, water with a needle-hole watering can until thoroughly watered, so that the cuttings and soil can tightly combine without gaps. Water is the key to survival of summer softwood cuttings, so full effort must be made in water regulation and management. After cutting, immediately set up a shade net, with light transmittance of 30% to 50% being best, and the shade net height from the seedbed surface generally 130 to 150 cm, which not only helps maintain moisture and lower temperature but also does not affect production management operations. In addition, promptly pull weeds, water, and loosen soil. Generally, when the surface soil of the seedbed is observed to become dry and begin to appear grayish-white, it can be watered, and each watering must be thorough; however, do not water too much, otherwise it is easy to cause soil compaction and mold growth, affecting rooting and survival. Generally, after rain, loosen the soil promptly to ensure the soil is loose and breathable, which is good for rooting, but when loosening the soil, be sure not to touch the cuttings. In mid-to-late October, when the weather is cool, the shade net can be removed, but in autumn drought, attention should still be paid to watering. In this way, by the second spring the Osmanthus can be outplanted or transplanted.