When does the jujube tree bloom, and when is the best time to transplant and prune it?

The jujube tree grows in mountainous areas, hills or plains below 1700 m in altitude. It is widely cultivated. This species is native to China and is often cultivated in Asia, Europe and the Americas. So when does the jujube tree bloom? What is the best time to transplant and prune it?

When does the jujube tree bloom? The jujube tree blooms from May to June, with small, yellow-green flowers in axillary cymes.

Biological habits of the jujube tree

The jujube tree, of the genus Ziziphus in the buckthorn family (Rhamnaceae), is a deciduous tree that can reach 10 m in height, with an oval crown. The bark is grayish-brown and fissured. The branches are divided into long branches, short branches and deciduous twigs. The long branches are reddish-brown, zigzag-curved, smooth, with stipular spines or without obvious spines; the short branches alternate on long branches more than two years old; the deciduous twigs are more slender, without buds, clustered on the short branches, and fall together with the leaves after autumn. The leaves are ovate to ovate-oblong, with a bluntly pointed tip, finely serrate margins, three basal veins, a glossy surface and no hairs on either side. It blooms from May to June, with small, yellow-green flowers in axillary cymes. The drupe is ovate to oblong, ripening from August to September, dark red when ripe. The stone is hard, pointed at both ends. The jujube is relatively drought-tolerant and needs little water; it is suitable for growing in poor soil, and the tree grows slowly, so its wood is hard and fine-grained, not easily deformed, and suitable for making carvings. A jujube wood rolling pin is the highest-quality rolling pin.

When is the best time to transplant a jujube tree

Although planting is possible in both spring and autumn, because jujube saplings require higher temperatures for rooting and sprouting, and because jujube saplings sprout late, autumn planting is not advocated in actual production; spring planting is the main practice. Under equal conditions, transplanting during the spring sprouting period can give a survival rate as high as over 90%. In northern regions, this is about late February to early May (temperatures above 18°C), because at this time the sap is already flowing, the jujube saplings begin to grow, the injured roots recover and regenerate easily, and nutrients from the underground part can be transported to the aboveground part in time, making survival easy. If planted too early in spring, the jujube saplings lose too much water, the roots find it hard to replenish it, and survival is affected.

What to pay attention to when transplanting a jujube tree

1. When planting, a 40*40 planting hole is the most standard treatment for the hole, but some people casually dig a hole and put the tree in and it still survives; how do you explain that? I still favor a 40*40 hole. The key is to pay attention to the treatment after the sapling is put into the hole. Soil filled into a 40*40 hole is surely looser than the soil of a small hole, and this is also more favorable for the jujube sapling to take root.

2. Do not put fertilizer in the bottom of the hole. Some people always like to put fertilizer in the planting hole of a newly planted tree, not realizing that this easily burns the roots; after watering, the fertilizer ferments and produces heat, which can cause the sapling to wither again after sprouting.

3. When burying the sapling, be careful not to bury it too deep. Under reasonable conditions, the higher the soil temperature, the easier it is for the sapling to take root. If buried too deep, the soil temperature is lower, which often costs more than it gains, causing the sapling to die, and even after sprouting it will grow slowly. The most reasonable approach is to bury it at the same soil layer depth at which it was lifted.

4. After the sapling is put into the hole, the soil first filled in should be stepped on with the feet so that the soil and roots are in close contact, and the soil added afterward should be treated the same way. What should be avoided most is not stepping at first and only stepping after the rest is buried; this easily causes wetness in clay soil, so that the top looks fine but after watering the lower part shrinks down, creating a hollow in the middle and drying out the roots and killing the sapling.

5. After watering well, regarding trunk heading, some say the lower the better, but that is not really so. It should be based on the condition of the land; basically it is enough to ensure that the head is not submerged when watering, and after heading, the tree head can be sealed with paint. Generally anything from 10 to 30 is fine.

6. After heading, lay plastic film promptly. First, it raises the soil temperature; second, it can retain water; third, it can prevent underground alkali from rising. Laying film is an important part of improving the survival rate.

7. Watering. After the sapling is buried, water it promptly. In sandy land, if possible, water 3 times in 10 days; normally, after the first watering, water a second time 3-5 days later. The first watering should soak through, and the second and third waterings follow. Do not believe certain books or old hometown experience; in Xinjiang the daytime temperature is extremely high, and without enough moisture the sapling will be steamed dry. Ensure the land is moist so that after planting the roots can absorb water fully. For special soils, such as class-two soil (clay), be careful: water must not be too frequent, otherwise root rot may occur. Treat specific matters specifically.

When is the best time to prune a jujube tree

Pruning of the jujube tree should follow the principle of “winter as the main season, combining winter and summer; early high yield and good quality, reasonable load”. The winter pruning period for jujube trees is best carried out from after leaf fall to before sprouting the following year; summer pruning can inhibit excessive growth of jujube shoots, reduce nutrient consumption, increase the fruit-setting rate, and improve the yield and quality of jujube fruit.

Pruning methods for the jujube tree:

For the pruning of dwarf and densely planted jujube trees, the sixteen-character pruning guideline of “promote early, control late, block the top, release the bottom, wipe, pinch, bend and twist, prop, pull, girdle and tie” should be strictly implemented.

Promote early, control late: in the early growth stage of the jujube tree (1-2 years), promote rapid growth of the jujube tree as much as possible to form a crown. Control late: once the crown is basically formed (after 3 years), take crown-control measures to control crown expansion and promote fruiting.

Block the top, release the bottom: use measures such as heading back and pinching to control the height growth of the crown; generally the crown height is controlled at about 2-2.5 m. Release the bottom: while the jujube tree is fruiting, take measures such as cutting back to promote new branch sprouting on the lower part of the jujube tree.

Propping branches: during the shaping of young trees, for branches with a small base angle and suitable direction, use wooden sticks to prop the branches to the ideal angle.

Pulling branches: use wire or rope to pull branches with useful value to a certain angle and orientation.

Girdling: 1 cm above the main bud, use scissors to score a ring around the trunk, deep to the xylem, to promote the main bud to sprout and produce new jujube shoots.

Tying: 1 cm above the main bud, tie the trunk with wire so that the wire sinks into the phloem, deep to the xylem; after the main bud sprouts, remove the wire promptly to prevent it from cutting into the trunk or severing the trunk.

Bud wiping: during the sprouting or growing period of the jujube tree, wipe off useless young buds sprouting on the jujube tree; this can be done several times a year, and they should be wiped off as soon as they sprout.

Pinching: when a jujube shoot has grown to a certain length, remove the new tip; the degree of pinching depends on the growth strength and size of the jujube shoot. Generally, pinch hard when growth vigor is weak, pinch lightly when growth vigor is strong; pinch lightly when there is large space, leaving 5-7 secondary branches; pinch hard when there is small space, leaving 2-4 secondary branches.

Bending: for newly grown branches whose bearing orientation and angle are not ideal, while they are not yet fully lignified, bend and guide them toward the needed space.

Twisting shoots: for new branches that have room to develop but whose growth orientation and angle are not ideal, while they are semi-lignified, use the hands to twist and injure them from the base so that the branches bend to the ideal orientation and angle.