In the real transaction of greenery seedlings, the quality of the seedlings directly impacts the quality of planting, survival rate, maintenance costs, and the greenery effect. Therefore, both the using units and the seedling supply units should pay attention to the basic standards of high-quality seedlings.

High-quality seedlings should meet the following standards:

Root system is well-developed and complete, with a short, straight taproot and a sufficient number of lateral and fibrous roots in the area near the root collar. It features an appropriate crown-to-root ratio, with no cracks in the large root system.

2. The seedlings are robustly growing, with full branches and strong resistance.

3. Seedlings have sturdy, straight trunks (except for vines), with considerable height and branches that do not grow excessively long.

4. The main lateral roots are evenly distributed, with a symmetrical and full canopy. Among them, the lower branches of evergreen coniferous trees do not wither and fall, forming bare trunks. Certain coniferous trees with strong stems and no latent buds exhibit a pronounced apical dominance, with well-developed lateral buds.

Tree trunks are free from diseases, pests, and mechanical damage.

To enhance the survival rate of high-quality landscaping trees, the shape and size of the tree canopy, as well as the age of the trees, significantly impact the survival rate during planting and are related to the adaptability and resistance of the trees after survival. Therefore, when transplanting different varieties, attention should be given to their distinct canopy shapes and tree ages.

1. Alley trees. Trunk height is appropriate, with fast-growing species like Poplar and Willow having a chest diameter of 4-6 cm, while slow-growing species such as Chinese scholar trees, Ginkgo, and Maple Triangle having a chest diameter of 5-8 cm, excluding large-sized seedlings). Branching points are consistent in height, with 3-5 evenly distributed, appropriately angled main branches. The branches and leaves are dense, and the trunk is intact.

2. Flowering shrubs. Possess 3-6 main stems or branches, height around 0.1 meters, evenly distributed, with branching at the base of the trunk, and a full, rounded canopy.

3. Solitary trees should have straight trunks, elegant individual postures, and distinctive features. Ornamental trees should have trunks over 2.01 meters high; evergreen trees should have complete canopies, lush foliage, and new branches growing; conifer trees should not have withered base and lower branches, appearing full and dignified.

4. Green Hedges: Seedlings with consistent height of 50-200 cm, not bare at the bottom; spherical crown seedlings with dense foliage.

Tomonaga: There are 23 perennial main stems without any dead branches.