What are the grafting methods for chrysanthemums in hot weather?
The chrysanthemum is one of China's four famous flowers and one of the most in-demand cut flowers in the world. So if you want to graft chrysanthemums, you must pay attention to the method, especially in hot weather, when the difficulty of grafting increases greatly. So how exactly should chrysanthemums be grafted in hot weather?
Chrysanthemum
There are many methods for grafting chrysanthemums; the most commonly used is the cleft grafting method. Both the rootstock and the scion should be growing vigorously, of moderate age and tenderness, with no white pith, and the rootstock should reach a thickness of 3 to 4 mm, slightly thicker than the scion. Collect and graft immediately; do not collect too many scions at one time, so as to avoid water loss affecting survival.
Select the top shoot of a chrysanthemum seedling 5 to 7 cm long as the scion. Remove the larger lower leaves, keeping two or three leaves at the tip. Use a blade to cut the scion into a 1.5 cm long wedge shape. Then cut off the rootstock at the grafting point, and use a knife to split the rootstock straight down the middle, to a depth slightly longer than or equal to the cut surface of the scion (1.5 to 2 cm). Insert the scion into the split, making sure the cambium layers of both are aligned, wrap the joint tightly from top to bottom with plastic strips, and apply mud to the cross-section of the rootstock to retain moisture, finally putting on a plastic bag and tying the bag opening securely. When bagging, the scion together with several Artemisia leaves below the joint should be placed inside the bag; handle carefully to avoid knocking off the scion, and the entire grafting process should be done quickly.
Key points for grafting chrysanthemums in hot weather
News from the China Landscape Web on August 10: When chrysanthemums are grafted in the hot and humid summer, the difficulty of grafting increases. To ensure the survival rate of grafting, preparatory work must be done before grafting, the grafting time must be chosen appropriately, and post-grafting management must be done well, providing suitable growing conditions to ensure the survival of the graft.
I. Preparatory work
1. Selecting the rootstock
Generally, Artemisia plants, which also belong to the Asteraceae family, are chosen as the rootstock, because Artemisia plants have strong compatibility with chrysanthemums and the survival rate after grafting is high. The Artemisia species selected should be perennial varieties with an upright main stem and many branches; common varieties include Artemisia annua, Aba Artemisia, Artemisia qinghaiensis, and wild mugwort.
2. Watering
Two or three days before grafting, water the rootstock and the mother plants of the scions thoroughly once to increase the water content of the scions and rootstock. If grafting is done on a hot, dry afternoon, spray water on the rootstock and the mother plants of the scions one or two hours before grafting, so that the mother plants do not suffer physiological wilting during grafting due to excessive water evaporation; wait until the water on the scion leaves has dried before grafting, to prevent excessive moisture during grafting from causing disease.
3. Preparing plastic bags
Prepare plenty of plastic bags; ordinary small plastic bags will do, and instant noodle plastic bags also work. Soak the bags completely in water and take them out, then use them after grafting to cover the grafted seedlings.
II. Grafting time
When grafting chrysanthemums in summer, the choice of time is very important. Avoid the high-temperature period and choose the cooler time of day for grafting. Generally it is best to graft on a cloudy day; if grafting on a sunny day, choose before 9 a.m. and after 5 p.m., to prevent excessive water loss from the scion and rootstock during grafting.
III. Grafting method
There are many methods for grafting chrysanthemums; the most commonly used is the cleft grafting method. Both the rootstock and the scion should be growing vigorously, of moderate age and tenderness, with no white pith, and the rootstock should reach a thickness of 3 to 4 mm, slightly thicker than the scion. Collect and graft immediately; do not collect too many scions at one time, so as to avoid water loss affecting survival. Select the top shoot of a chrysanthemum seedling 5 to 7 cm long as the scion. Remove the larger lower leaves, keeping two or three leaves at the tip. Use a blade to cut the scion into a 1.5 cm long wedge shape. Then cut off the rootstock at the grafting point, and use a knife to split the rootstock straight down the middle, to a depth slightly longer than or equal to the cut surface of the scion (1.5 to 2 cm). Insert the scion into the split, making sure the cambium layers of both are aligned, wrap the joint tightly from top to bottom with plastic strips, and apply mud to the cross-section of the rootstock to retain moisture, finally putting on a plastic bag and tying the bag opening securely. When bagging, the scion together with several Artemisia leaves below the joint should be placed inside the bag; handle carefully to avoid knocking off the scion, and the entire grafting process should be done quickly.
IV. Post-grafting management
The main management work after grafting is shading and watering. In summer, temperatures are high and sunlight is strong, so the newly grafted chrysanthemums should immediately be shaded: build a simple arched shed and cover it with shade netting for shading. The arched shed can also be covered with a layer of film to prevent summer rain. Two or three days later, open a small vent in the plastic bag covering the grafted seedling for ventilation, and observe carefully. If the scion shows no signs of water loss or wilting and has basically survived, remove the shading material; the film can be left in place for now. On sunny days, pay attention to spraying water, three or four times a day, and at the same time strengthen ventilation inside the shed and the bag to prevent overly stuffy and hot conditions, so that the scion grows normally and gradually adapts to the external environment. If the scion inside the bag is found to have wilted and died, re-graft promptly. After about 20 days, the scion begins to grow rapidly; the plastic strips tied around the scion should be removed promptly, and normal management can then begin.
How to ensure chrysanthemum grafting survival in summer heat
The high temperatures of summer make chrysanthemum grafting more difficult and the survival rate extremely low. Through several years of practice and exploration, the author has initially mastered the technique of grafting chrysanthemums in the high-temperature season of July and August, and achieved good results. Chrysanthemum grafting is a complex and meticulous task; besides mastering the above technical points, the operation must also be done carefully, attentively, quickly, and accurately, and daily management requires frequent observation, thinking, and handling.
I. Grafting time
A cloudy day is the best time for grafting chrysanthemums in the high-temperature season, followed by before 10 a.m. and after 4 p.m. on windless days; during these periods the temperature is 5°C to 7°C lower than the day's highest temperature, and the rootstock and scion lose relatively less water.
II. Preparation before grafting
1. Watering: Two or three days before grafting, water the rootstock and the mother plants of the scions thoroughly once to increase the water content of the scions and rootstock.
2. Spraying: One or two hours before grafting (mostly referring to hot, dry afternoons), spray water on the rootstock and the mother plants of the scions, so that the mother plants do not suffer physiological wilting during grafting due to sun exposure, but note that grafting should begin only after the water on the leaf surfaces has completely evaporated.
3. Preparing bags: Prepare plenty of plastic bags (instant noodle bags will do). Soak the bags completely in water and take them out, for use in bagging after grafting.
III. Grafting method
Use the cleft grafting method. Both the rootstock and the scion should be growing vigorously, of moderate age and tenderness, with no white pith, and the rootstock should reach a thickness of 3 to 4 mm (slightly thicker than the scion). Collect and graft immediately; do not collect too many scions at one time, so as to avoid water loss affecting survival.
Select the top shoot of a chrysanthemum seedling 5 to 7 cm long as the scion. Remove the larger lower leaves, keeping two or three leaves at the tip. Use a double-edged blade to cut the scion into a 1.5 cm long wedge shape, and after cutting, hold it in your mouth; be sure not to let it touch saliva, so as not to affect the compatibility of the two. Then cut off the rootstock at the grafting point, and use a knife to split the rootstock straight down the middle, to a depth slightly longer than or equal to the cut surface of the scion (1.5 to 2 cm). Insert the scion into the split, making sure the cambium layers of both are aligned, wrap the joint tightly from top to bottom with plastic strips, and apply mud to the cross-section of the rootstock to retain moisture, finally putting on a plastic bag and tying the bag opening securely. When bagging, the scion together with several Artemisia leaves below the joint should be placed inside the bag; if there are few or small Artemisia leaves below the joint, pick a few leaves from elsewhere, soak them in water, and then place them into the bag. Handle carefully to avoid knocking off the scion, and the entire grafting process should be done quickly.
IV. Post-grafting management
Immediately after grafting, take shading measures. For small areas, soak newspaper or kraft paper in water and then use bamboo poles as supports to cover all the grafting points. In the first day or two, spray water promptly whenever the newspaper or kraft paper dries out; do not spray too much water, just enough to moisten the paper, as too much can crush the scions. For larger areas, shade netting can be used for shading. Two or three days later, open a small vent in the plastic bag for ventilation, and observe carefully. If the scion shows no signs of water loss or wilting, the shading material can be removed after six or seven days. Once the scion has basically survived, remove the shading material. On sunny days, pay attention to spraying water, three or four times a day, and at the same time enlarge the vent in the bag; when the weather is especially dry and hot, spray a small amount of mist into the bag, so that the scion gradually adapts to the external environment. If the scion inside the bag is found to have wilted and died, re-graft promptly. After about 20 days, the scion begins to grow rapidly; the plastic strips tied around the scion should be removed promptly.