Planting Methods and Key Technical Points for Longan Saplings

Before planting longan saplings, first prepare the land by deep plowing the entire area and digging large holes at a spacing of 5 m×7 m between plants and rows, and apply sufficient base fertilizer. Then transplant the saplings in spring from February to March or in autumn from September to October. Place the sapling with its root ball into the hole, cover the roots with fine topsoil and firm it down, water with root-setting water, and simply keep the soil moist. After planting, also pay attention to the following points:

1. Pruning

Longan trees should be trained into a natural round-headed canopy. Generally, within 2-3 years after transplanting, once the trunk is 0.5-1 m and there are 3-4 main branches evenly distributed, prune year by year to increase the number of branching orders, finally forming a round-headed canopy. Within 3-5 years after transplanting, all flower spikes that appear should be pruned off to reduce nutrient consumption and promote strong growth of summer and autumn shoots. Branches killed by witches' broom disease should be burned immediately. In addition, branches such as drooping branches, overly dense branches, pest- and disease-damaged branches, and dead or old branches should be pruned in time.

2. Fertilizing

Fertilizing can begin 1 month after the longan tree is transplanted. It is recommended to apply “two fertilizers per shoot”, that is, apply the 1st fertilizer when the terminal bud of the shoot begins to swell; apply the 2nd fertilizer when the new shoot has basically stopped elongating and the leaf color changes from red to green. In addition, in November-December each year, apply winter fertilizer based mainly on organic manure.

Generally, fertilize by opening 3-4 shallow holes or a shallow ring trench at the outer edge of the longan tree's root zone, apply the fertilizer into the holes or trench, and cover with soil afterward. In the dry season, liquid fertilizer is preferable. At the same time, a 0.2%-0.3% potassium dihydrogen phosphate solution can be applied together with pesticide spraying.

3. Watering

Before flowering (after autumn shoots mature — late flower bud differentiation), keep the soil relatively dry. From the flowering stage to the autumn shoot sprouting stage, keep the soil moist and the water supply balanced. Irrigate (or sprinkle water) during drought, and promptly drain excess water after rain.

4. Pest and Disease Control

Downy mildew, damping-off, litchi stink bug, psyllid, termite, and lantern fly are all pests and diseases that commonly attack longan trees. Growers should take preventive measures in advance and spray the corresponding pesticides.