What grafting methods can be used for osmanthus in the north
Growing osmanthus in the northern regions often faces challenges such as low temperatures and alkaline soils. Reasonably selecting the rootstock can significantly improve the survival rate. This article systematically analyzes the key grafting techniques for osmanthus in the north, from the selection of rootstock, timing control to operational details, to help you cultivate high-quality plants with strong stress resistance.
Selection of Rootstock for Grafting Osmanthus in the North
Comparison of Characteristics of Four Preferred Rootstocks
Small-leaf ligustrum, with a survival rate of over 90%, becomes the first choice, as its developed root system can effectively absorb nutrients from deep layers. The rootstock of the flowingery tree can increase the cold resistance of the grafted seedlings by 40%, allowing them to survive in temperatures as low as -15°C, especially suitable for the cold regions of the north. Large-leaf ligustrum and water wax trees have good salt and alkali resistance, adapting to soil environments with a pH of 7.5-8.2.
Analysis of the Advantages of Using Wild Seedlings for Grafting
When using wild seedlings of osmanthus as the rootstock, the synchronization rate of cambium cell division reaches up to 98%, and the healing period of the scion can be shortened by 3-5 days. It is recommended to use robust wild seedlings that are 2 years old with a ground diameter of 0.8cm or more to ensure a smooth nutrient transport channel.
Timing Control for Grafting Osmanthus in the North
Accurate Determination of Phenological Period
The best time is when the day-night temperature difference is stable between 8-12°C and the bark of the rootstock is easy to separate. In the four northern provinces (Heilongjiang, Jilin, Liaoning, Inner Mongolia), it is suitable to perform grafting between April 20 and May 15, and in the Beijing-Tianjin-Hebei region, it can be brought forward to around April 10.
Skills for Microclimate Adjustment
In case of late spring cold snaps, a temporary shed can be set up using double-layer sunshades to maintain a temperature control environment of 18-25°C during the day and 12-15°C at night, which can increase the success rate of grafting by 20%.
Step-by-Step Illustration of Grafting Practice
Scientific Scion Treatment Method
Select one-year-old branches with a diameter of 0.6-1cm, retaining a leaf area of no more than 8cm². Use a double-sided 30-degree oblique cutting method, controlling the cutting surface length to 3-3.5cm to ensure maximum contact area of the cambium.
Essentials of Insertion Grafting Technique
The depth of the cut on the rootstock should be equal to the length of the scion's cutting surface, and the alignment error of the cambium must be less than 0.2mm. When binding, use a spiral wrapping method, applying a uniform pressure of 0.5kg to secure the scion without damaging the tissue.
Postoperative Meticulous Management
Keep the humidity at 85%-90% after bagging, ventilate twice a day for 15 minutes each time. When the new shoots reach 10cm, start to untie the bindings, gradually removing the plastic film in three steps to avoid sudden decompression at the joint causing breakage.
By scientifically selecting rootstock varieties, accurately grasping the timing of grafting, and standardizing the operation process, the survival rate of osmanthus grafting in the north can reach over 85%. It is recommended to prioritize using the flowingery tree rootstock to enhance cold resistance, combined with progressive unbinding management, to cultivate high-quality osmanthus seedlings that can adapt to temperatures as low as -20°C.