Bonsai cultivation techniques of Ginkgo biloba

Ginkgo, also known as ginkgo, is a living fossil of plants left over from ancient times. it is an economic plant for both medicine, food and wood. Ginkgo biloba has strong vitality, tall and straight trunk, elegant tree shape and beautiful leaf shape. it is not only a dried fruit tree with high economic value, but also a beautiful landscaping tree species, but also a unique good material for bonsai production. Ginkgo bonsai is deeply loved by people because of its unique shape and profound cultural connotation.

I. growth characteristics

Ginkgo biloba is a dioecious gymnosperms, but both female and male flowers are small and not obvious, so they have no ornamental value. The seeds (not fruits) of Ginkgo biloba are not distinctive in appearance, they generally fall off completely before the end of October, and the ornamental value is not great. Moreover, ginkgo biloba cannot blossom in areas south of 24 degrees north latitude with an annual average of 20 ℃. Therefore, ginkgo bonsai should be based on leaf viewing and modeling. However, ginkgo biloba is a deciduous tree with deciduous leaves in winter, which greatly reduces its ornamental value and greatly affects the market value of ginkgo bonsai. Preventing ginkgo leaves from falling in winter is the key to the production of ginkgo bonsai. Making beautiful ginkgo bonsai involves the cultivation of ginkgo plant, bonsai production and prevention of winter defoliation and other technical links.

Second, sowing seeds

Ginkgo generally uses seeds (ginkgo) as sowing material, but the water content of commercial ginkgo is too high, direct sowing is easy to cause rotten fruit. Ginkgo biloba seeds should be dried indoors until the water content is about 30% before sowing. Ginkgo seeds usually begin to germinate after a dormant period of 1 to 2 months, so there are two ways to sow ginkgo biloba seedlings: one is to sow dried ginkgo directly on the seedbed in autumn, and the following spring seeds germinate; second, 50 days before sowing, ginkgo is buried in wet river sand with a moisture content of 5%, 10%, covered with plastic film, and then sown in spring. The seedbed matrix can be mixed with vegetable garden soil, river sand and compound fertilizer at 50:50:1 to form a seedbed with 100cm wide, 15cm high and 300500cm long. When sowing, the seeds of Ginkgo biloba must be laid flat, covered with 3-5 cm of soil, covered with straw after sowing, and watered every 7 days for autumn sowers and every 3 days for spring sowers until seedlings emerge. After emergence, the seedlings were drenched with thin water once a day, and 0.3% potassium dihydrogen phosphate was applied to each square meter seedbed every week (1500 ml).

3. Raising seedlings

When the height of the seedlings is more than 15 cm, they should bring the soil to the pot and cut off the terminal buds to promote the germination of lateral buds. The seedling pot can choose the plastic flowerpot or seedling bag with a diameter of about 15 cm. The basin soil requires more organic matter and good water permeability and air permeability. When the lateral branch is 20 cm long, it can be bound and bent with fine hemp rope for shaping. Potted seedlings should be placed in a shade from May to October to prevent strong light from inhibiting growth and burning tender leaves. Potted seedlings should be watered every 2 to 3 days, and the pot soil should be moist. Fertilization is mainly based on rotten bean cake or compound fertilizer, once in February and August each year.

IV. Planting and management

When the ginkgo seedlings are 10 cm off the ground and the diameter is more than 1.5 cm, the soil should be moved to a large basin for planting. The bottom of the planting basin should be perforated to prevent waterlogging on rainy days, preferably on bricks. Soak in water once a week after planting. The trunk is smeared with Bordeaux liquid in winter every year to prevent ant damage. When the new branches grow to more than 20 cm in the next year, they can be shaped as needed, or grafted before sprouting in early spring every year.

Ginkgo biloba has two growing seasons in spring and autumn every year in the south. It stops growing because of high temperature in summer and low ground temperature in winter. Therefore, the fertilization of ginkgo biloba should be carried out in spring and autumn every year. Similarly, the pruning of ginkgo biloba is generally carried out in summer and winter.

Fifth, prevent leaves from falling in winter

Ginkgo biloba is a deciduous tree, the leaves begin to turn yellow and gradually fall after late autumn every year, and then the plant goes into dormancy. The reason of ginkgo leaf defoliation is not only due to the influence of low temperature, but also the result of its own physiological law. Our experiments for many years have shown that it is feasible to postpone the defoliation of ginkgo biloba by artificial method. At present, the more effective method is to spray foliage before the cold spell in autumn and winter, and cover it with plastic film to increase temperature and moisturize, so as to maintain the continuous growth of Ginkgo biloba.

Another effective method to prevent defoliation in winter is the secondary shoot technique, that is, artificial treatment can make ginkgo leaves fall ahead of time and sprout new branches for the second time in the same year. Usually in the second growing season of Ginkgo biloba every year (October), the leaves are treated with chemicals or artificially cut, and the long branches are truncated to promote the germination and growth of lateral buds. The secondary shoot technology must also be matched with fertilization and heat preservation measures in order to achieve ideal results.