Detailed Explanation of Ginkgo Tree Propagation Methods and Seedling Cultivation Techniques
Ginkgo prefers deep loam that is moderately moist and well-drained. It is suited to growing in subtropical monsoon regions with relatively favorable hydrothermal conditions. It grows well in both acidic and calcareous soils, with neutral or slightly acidic soil being the most suitable. It does not tolerate waterlogged sites and is relatively drought-tolerant, but grows poorly in overly dry places, on rocky slopes, or in low-lying wet areas. Now let us take a look 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 plants dwarfed, fuller, and higher-yielding. 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 and vigorous 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 branches. Fruiting begins 5 to 8 years after grafting.
Seed Propagation
Seed propagation is mostly used for large-scale landscaping seedlings or for making clump-style bonsai. After collecting seeds in autumn, remove the outer seed coat and dry the seeds with the fruit coat still attached. 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 mixed-sand stratification 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. 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 should be chosen on a well-drained site to prevent waterlogging from rotting the parts of the seedlings near the ground.
Cutting Propagation
1. Hardwood cuttings: Generally in spring from March to April, cut vigorous, 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 can form in about 40 days. After survival, carry out normal management, and they can be transplanted in spring of the second year. This method is suitable for large-scale landscaping seedling production and the like.
2. Softwood cuttings: 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. Pay attention to shading and maintain air humidity. After roots develop, transplant them with soil.
Sucker Propagation
The roots of large trees readily produce large numbers of suckers. If allowed to grow naturally for many years, they can form the ginkgo garden landscape known as "holding a child in the bosom." If the root suckers are cut off to propagate seedlings, it not only saves seeds but also results in fast growth and earlier flowering and fruiting. Sucker propagation can use two methods: separation and propagation of existing root suckers, and digging trenches to cut roots and stimulate new suckers.
1. Separation and propagation of existing root suckers: Using existing root suckers for separation and propagation is the simplest method. Every year from July to August, first perform ring barking at the base of the root sucker, then mound soil around it. After more than 1 month, new roots will emerge from the ring-barked area, and in spring of the second year it can be separated from the mother plant and directly planted in place.
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 fill it back with soil mixed with fertilizer. After 1 year of growth, it can be separated to form a new seedling. Small seedlings propagated from suckers can be directly planted in place without further cultivation in a nursery. Therefore, although it is called sucker seedling propagation, it is in fact sucker planting in place.
Propagation Methods for Ginkgo Trees
Ginkgo trees have graceful tree forms and golden-yellow leaves in autumn. They are suitable as shade trees, street trees, and ornamental trees, and are often chosen as a preferred tree species for landscaping. There are many propagation methods for ginkgo, roughly four: sowing, suckering, cutting, and grafting.
Seed Propagation
After the seeds are harvested in autumn, remove the outer seed coat and dry the seeds with the mesocarp still attached. 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 mixed-sand stratification to promote germination). When sowing, place the seed embryo horizontally in the sowing furrow, then cover with 3 cm to 4 cm of soil and firm it down. Seedlings can grow to 15 cm to 25 cm tall in the same year. After leaf fall in autumn, they can be transplanted.
It must be noted that seed propagation requires the establishment of a dedicated nursery. The nursery should be chosen in a place with relatively high terrain, good drainage, sufficient water sources, and convenient irrigation. At the same time, it should be carefully plowed and harrowed, the ground leveled, sufficient basal fertilizer applied, and attention paid to controlling underground pests. The sowing quantity depends on the size of the ginkgo nuts. Generally, about 25 kg is sown per mu, which can produce 15,000 to 20,000 seedlings. When opening furrows for sowing, first water the bottom, then place the ginkgo nuts sideways in the furrow. If they have already sprouted, place the sprout tip downward, then cover with about 3 cm of soil to finish.
If conditions permit, after covering with soil, another layer of plastic film should be placed over it to maintain moisture and temperature. When the embryo sprouts emerge, aerate appropriately and gradually uncover the film. After June, shading should be provided where conditions permit. In the first year, ginkgo seedlings are tender and weak, so excessive chemical fertilizer should not be applied; keep to light, diluted fertilization. If heavy rain occurs, drain water promptly and loosen the soil in a timely manner.
Sucker Propagation
This is carried out using the root-collar suckers of ginkgo trees, and sucker propagation is a commonly used method. Because ginkgo trees are often top-grafted onto large rootstocks, the roots of large trees readily produce large numbers of suckers. If allowed to grow naturally for many years, they can form the ginkgo garden landscape known as "holding a child in the bosom." If the root suckers are cut off to propagate seedlings, it not only saves seeds but also results in fast growth and earlier flowering and fruiting.
Sucker propagation can use two methods: first, separation and propagation of existing root suckers; second, digging trenches to cut roots and stimulate new suckers. Using existing root suckers for separation and propagation is the simplest method. Every year from July to August, first perform ring barking at the base of the root sucker, then mound soil around it. After more than one month, new roots will emerge from the ring-barked area, and in spring of the second year it can be separated from the mother plant and directly planted in place.
Digging trenches to cut roots and stimulate new suckers is done in autumn. 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 fill in soil mixed with fertilizer. After one year of growth, it can be separated to form a new seedling. Small seedlings propagated from suckers can be directly planted in place without further cultivation in a nursery. Therefore, although it is called sucker seedling propagation, it is in fact sucker planting in place.
Cutting Propagation
Cutting propagation is divided into hardwood cuttings and softwood cuttings.
Hardwood cuttings are generally taken in spring from March to April, cutting vigorous, plump 1- or 2-year-old branches from the mother plant into cuttings 10 cm to 15 cm long each, and inserting them into fine yellow sand or loose soil. After insertion, water thoroughly and keep the soil moist. Roots can form in about 40 days. After survival, carry out normal management. They can be transplanted in spring of the second year. This method is suitable for large-scale landscaping seedling production and the like.
Softwood cuttings are taken in early July. Take semi-lignified branches of the current year, cut them into cuttings with 2 buds per node or 3 buds per node, soak them in 100 ppm ABT rooting powder, then insert them into an air-permeable sandy soil seedbed. Pay attention to shading and maintain air humidity. After roots develop, transplant them with soil into a regular seedbed.
Grafting Propagation
Grafting propagation is the main propagation method in ginkgo cultivation. It can bring fruiting earlier and make plants dwarfed, fuller, and higher-yielding. Grafting is generally carried out from mid-March to early April in spring 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 and vigorous 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 branches. Fruiting begins 5 to 8 years after grafting.
Introduction to the Four Major Propagation Methods for Ginkgo Trees
Image: Ginkgo grafting methods
[Common Question] What propagation methods are there for ginkgo trees?
[Expert Answer]
1. Seed propagation
After the seeds are harvested in autumn, remove the outer seed coat and dry the seeds with the mesocarp still attached. 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 mixed-sand stratification to promote germination). When sowing, place the seed embryo horizontally in the sowing furrow, then cover with 3~4 cm of soil and firm it down. Seedlings can grow to 15~25 cm tall in the same year. After leaf fall in autumn, they can be transplanted. It must be noted that seed propagation requires the establishment of a dedicated nursery. The nursery should be chosen in a place with relatively high terrain, good drainage, sufficient water sources, and convenient irrigation. At the same time, it should be carefully plowed and harrowed, the ground leveled, sufficient basal fertilizer applied, and attention paid to controlling underground pests. The sowing quantity depends on the size of the ginkgo nuts. Generally, about 25 kg is sown per 667 sq m, which can produce 15,000~20,000 seedlings. The sowing row spacing is 20~30 cm, and the plant spacing is 10 cm. Either bed sowing or furrow sowing can be used. When opening furrows for sowing, first water the bottom, then place the ginkgo nuts sideways in the furrow. If they have already sprouted, place the sprout tip downward, then cover with about 3 cm of soil, and then cover with a layer of plastic film to maintain moisture and temperature. When the embryo sprouts emerge, aerate appropriately and gradually uncover the film. After June, shading should be provided where conditions permit. In the first year, ginkgo seedlings are tender and weak, so excessive chemical fertilizer should not be applied; keep to light, diluted fertilization. If heavy rain occurs, drain water promptly and loosen the soil in a timely manner.
2. Sucker propagation
The roots of large trees readily produce large numbers of suckers. If allowed to grow naturally for many years, they can form the ginkgo garden landscape known as "holding a child in the bosom." If the root suckers are cut off to propagate seedlings, it not only saves seeds but also results in fast growth and earlier flowering and fruiting.
Sucker propagation can use two methods: first, separation and propagation of existing root suckers. Second, digging trenches to cut roots and stimulate new suckers.
Using existing root suckers for separation and propagation is the simplest method. Every year from July to August, first perform ring barking at the base of the root sucker, then mound soil around it. After more than 1 month, new roots will emerge from the ring-barked area, and in spring of the second year it can be separated from the mother plant and directly planted in place; digging trenches to cut roots and stimulate new suckers 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 fill in soil mixed with fertilizer. After 1 year of growth, it can be separated to form a new seedling. Small seedlings propagated from suckers can be directly planted in place without further cultivation in a nursery. Therefore, although it is called sucker seedling propagation, it is in fact sucker planting in place.
3. Cutting propagation
(1) Hardwood cuttings: Generally in spring from March to April, cut vigorous, plump 1- or 2-year-old branches from the mother plant into cuttings 10~15 cm long each, and insert them into fine yellow sand or loose soil. After insertion, water thoroughly and keep the soil moist. Roots can form in about 40 d. After survival, carry out normal management. They can be transplanted in spring of the second year. This method is suitable for large-scale landscaping seedling production and the like.
(2) Softwood cuttings: 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. Pay attention to shading and maintain air humidity. After roots develop, transplant them with soil.
4. Grafting propagation
Grafting propagation is the main propagation method in ginkgo cultivation. It can bring fruiting earlier and make plants dwarfed, fuller, and higher-yielding.
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 20~30-year-old plants with strong growth and vigorous fruiting. Generally, 3~4-year-old branches bearing about 4 short shoots are chosen as scions, and each plant is usually grafted with 3~5 branches. Fruiting begins 5~8 years after grafting.
[Editor's Comments] Ginkgo can be propagated through a variety of methods. The most commonly used are mainly seed propagation, cutting propagation, and division propagation, and it can also be propagated by grafting. These four methods are the most common ways to propagate ginkgo. One can also adopt the method of horizontal planting to propagate seedlings from seedlings in order to accelerate seedling propagation. Using laboratory tissue culture is also a way to promote propagation.