In the spring of 2021, when doing things in a unit, I saw that the greening of this unit was very outstanding, whether it was tall trees, or some low shrubs, and even some ground covers were lush, the whole unit was full of green vitality, but at the other end of the unit office building, there was a 20 cm osmanthus leaf leaf that almost all fell off, take a closer look, some of the new branches of the year have died, perhaps because they have many years of experience in landscaping. I found the relevant person in charge of the unit and learned the reason for the dead yellow leaves of this osmanthus tree.
The person in charge said that this osmanthus tree has been planted for more than ten years, has been growing very well, in the maintenance of many years are the same, every year when the Laurel blossoms bloom, full of trees golden, this can be fragrant ten miles, many people in the local area know that there is a osmanthus tree in the unit, but do not know what the reason, in 2020 the growth is not strong enough, the leaves are getting worse and worse. When asked what fertilizer has been applied, the answer is still no, of course, do not say the reason for the lack of fertilizer, because after the trees in the green space survive, many do not need to be fertilized.
Subsequently, the fallen leaves caused by drought were ruled out, because if it was a drought, the leaves would fall quickly after turning yellow, and the unit also watered the osmanthus tree when it was guarding other seedlings. Of course, I don't say the reason for the water, because the flower beds here are much higher than the ground level, and the rain will not accumulate water. Some people say that it may be termites or other underground pests, so last year when it was still watering, some pesticides to treat underground pests were rushed in, but it did not work.
I asked when the flower bed around the tree was cut, the person in charge said that this flower bed was cut in 2018, when the courtyard was renovated, in order to preserve this osmanthus tree was cut with brick cement, and then filled with soil, when measured a full 60 centimeters, immediately I told them that it may be the reason for this flower bed, is the osmanthus tree was buried too deep, and then learned that when planting the osmanthus tree, because considering his preciousness, the tree is relatively large, it was planted with an excavator and a crane. Buried relatively deeply, coupled with the construction of a flower bed, thickening the soil layer, resulting in osmanthus tree root system hypoxia breathing difficulties.
In order to protect the osmanthus tree, it is recommended that the unit remove the flower bed, sure enough, after digging the flowering altar, buried in the trunk below the soil layer, some have begun to rot in flaks, and then it is recommended to dig more soil layer, so that the roots of the trunk are exposed, after drying for two days, use carbendazim + agricultural streptomycin + rooting agent + plant growth regulator for three times a month irrigation, and arrange as much as possible not to accumulate water, to ensure that the osmanthus tree can not only breathe normally, but also have enough nutrients and plant hormone stimulation.
After the careful management of the unit, this spring and the osmanthus tree for nutrient infusion, in June have been issued new shoots, in order to avoid the high temperature caused by the burn, affect the growth of the osmanthus tree, and recommended the use of 70% of the shade net, and many times the leaves sprinkled, the current whole osmanthus tree has grown vigorously, and presented a lush scene.