Ginkgo Tree Propagation Methods
Successful Ginkgo tree propagation methods are many and diverse. Growing from seed, cuttings, layers, and grafts are all accepted, widespread methods in use. Each has a role to play in the continued cultivation of this ancient plant.
Growing the Gingko, or Maidenhair, tree from seed is not difficult. The seeds are gathered in October. A smelly outer layer must be carefully washed away. The butyric acid it contains causes nausea and dermatitis. It is also responsible for the smell that is similar to rancid butter. The seeds need to warm stratify for a period of two months. This is a period of time when the embryos develop as the seeds rest undisturbed at temperatures of 68 to 86 degrees Fahrenheit. After this, the seeds must cold stratify for another two months at temperatures of 34 to 41 degrees Fahrenheit. It is vital for the seeds to remain moist during this process. To maintain adequate water content, growers often cover the seeds with damp vermiculite or peat moss. The stratification process complete, the seeds are ready for germination and planting. The Gingko thrives in full sun to light shade. It prefers fertile, heavy, moist soil with good drainage. With protection from the wind, regular watering and feeding, the Gingko rapidly becomes established.
Gingko trees are frequently grown from cuttings. Determining the sex of a young Gingko can be difficult. In raising trees from cuttings, the sex is assured. Male trees are often selected for use in landscaping urban areas. The Gingko's tall, upright habit, pest and disease resistance and tolerance of pollutants make it an ideal choice. The female trees, with their smelly fruit, are less desirable for such applications. In Japan, the female trees are preferred, as the fruit is a popular food source. Cuttings are an efficient way to consistently produce plants of a known quality and gender. Softwood cuttings are taken in the spring. Semi-ripe cuttings are available in early summer, and hardwood cuttings in the fall. Cuttings are treated with rooting hormone. Kept moist, they develop roots within a couple of weeks and are ready for planting.
Air layering Gingko trees is a method of propagation similar in some respects to cuttings. Instead if severing a portion of the parent tree immediately, a wound is made to the bark of a stem or tip. Rooting hormone is applied, and the damaged area covered. Root growth is encouraged by this method, while the stem still receives nourishment from the parent plant. When an adequate root system is developed to sustain the new plant, it is removed from the parent and planted. This method allows for the development of larger new plants with more highly developed roots than traditional cuttings.
Finally, grafting has a role to play in Gingko tree propagation. In nature, a male and female Gingko must grow in close proximity to allow the development of fertile seeds. By grafting branches of one sex onto trees of the other, pollination can occur without the risks of overcrowding. Mature trees lacking a suitable counterpart can thus remain viable contributors to the continuation of the species.