A Detailed Guide to the Latest Propagation Methods for Ginkgo Trees

Ginkgo prefers deep loam that is moderately moist but well-drained, and is suited to growing in subtropical monsoon regions with relatively favourable hydrothermal conditions. It grows well in both acidic and calcareous soils, but neutral or slightly acidic soil is most suitable. It does not tolerate waterlogged sites and is relatively drought-tolerant, though it grows poorly alone in overly dry places, on stony hillsides or in low, damp sites. Let's take a look together at the propagation methods for ginkgo trees!

Grafting Propagation

Grafting propagation is the main propagation method in ginkgo cultivation. It can bring fruiting earlier and make the plant dwarfed, full and highly productive. Grafting is generally carried out from mid-March to early April using methods such as side-veneer grafting, bark grafting or cut grafting. Scions are mostly selected from 20- to 30-year-old plants with strong growth vigour and abundant fruiting. Generally, 3- to 4-year-old branches bearing about 4 short shoots are chosen as scions, and each plant is usually grafted with 3 to 5 scions. After grafting, fruiting begins in 5 to 8 years.

Seed Propagation

Seed propagation is mostly used for large-scale landscaping seedlings or for making clump-style bonsai. After harvesting the seeds in autumn, remove the outer seed coat, dry the seeds with the fruit coat still on, and they can be sown in winter of the same year or in spring of the following year. If sown in spring, they must first undergo stratification with sand to promote germination. When sowing, place the seed embryo horizontally in the sowing furrow, then cover with 3 to 4 cm of soil and firm it down. The seedlings can grow to 15 to 25 cm tall in the same year. After leaf fall in autumn, they can be transplanted. Note, however, that the seedbed must be chosen in a well-drained area to prevent waterlogging from rotting the part of the seedling near the ground.

Cuttage Propagation

1. Hardwood cutting: Generally in spring, from March to April, cut healthy, plump 1- or 2-year-old branches from the mother plant, cut them into cuttings 10 to 15 cm long each, and insert them into fine yellow sand or loose soil. After insertion, water thoroughly and keep the soil moist; roots will form in about 40 days. After they survive, carry out normal management, and they can be transplanted in the spring of the second year. This method is suitable for large-scale landscaping seedling production, etc.

2. Softwood cutting: In early July, take semi-lignified branches of the current year, cut them into cuttings with two buds per node or three buds per node, soak them in 100 mg/kg ABT rooting powder, then insert them into an air-permeable sandy soil seedbed. Take care to provide shade and maintain air humidity, and after roots have formed, transplant them with the soil ball.

Sucker Propagation

The roots of large trees easily produce large numbers of suckers. If left to grow naturally for many years, they can form the ginkgo garden landscape known as “a child held in the arms”. If the root suckers are cut away to propagate seedlings, it not only saves seeds but also grows quickly and flowers and fruits early. Sucker propagation can use two methods: propagation by cutting off existing root suckers, and propagation by digging trenches to cut roots and stimulate new suckers.

1. Propagation by cutting off existing root suckers: Using existing root suckers and cutting them off is the simplest method. Every year from July to August, first carry out ring-barking at the base of the root sucker stem, then mound soil over it. After more than 1 month, new roots will emerge at the ring-barked area, and in the spring of the second year they can be cut away from the mother plant and planted out directly.

2. Digging trenches to cut roots and stimulate new suckers: This is done in autumn. At that time, at a suitable place near a large ginkgo tree, dig a ring-shaped trench 50 cm deep and 50 cm wide, cut the lateral roots, then refill with soil mixed with fertiliser. After 1 year of growth, they can be cut away to form new seedlings. Small seedlings propagated from suckers can be planted out directly without further raising in a nursery; therefore, although it is called sucker seedling raising, it is in fact sucker planting out.