How to Treat Black Stems in Epipremnum aureum
Epipremnum aureum, a common indoor green plant, is困扰ing many plant enthusiasts with the issue of blackening stems. This phenomenon not only affects the ornamental value but may also threaten the plant's survival. This article will systematically analyze the causes of black stems and provide targeted solutions to help your Epipremnum aureum rejuvenate.
I. Environmental Control: Temperature and Humidity Management
1.1 Improper Temperature Leading to Frost Damage
Epipremnum aureum is native to tropical rainforests and thrives best at temperatures between 18-28°C. When the indoor temperature drops below 10°C during winter, the cell tissue can be damaged by low temperatures, leading to black stems. It is recommended to move the frost-damaged plant to an air-conditioned room or use a thermal cover to maintain a day-night temperature difference of no more than 5°C.
1.2 Humidity Balance Techniques
In conjunction with temperature regulation, a humidifier or water tray can be placed to increase the ambient humidity to 60%-80%. Be cautious to avoid dew formation on the leaves at night and it is suggested to complete the misting for humidity increase before 10 a.m. daily.
II. Root System Repair: Scientific Repotting Techniques
2.1 Standards for Potting Removal Inspection
Immediate potting removal is required when two or more leaves turn yellow and droop. Healthy roots should be milky white with a diameter of 1-2mm. If more than one-third of the roots show brown and soft rot, emergency treatment is needed.
2.2 Root Pruning and Disinfection Process
Use scissors disinfected with alcohol to make a 45-degree oblique cut on the diseased roots. Retain a 5cm healthy stem segment, soak in a carbendazim solution (1:800) for 30 minutes, and then place in a shaded and well-ventilated area to air-dry the roots for 4 hours.
III. Disease Control: Systemic Fungicidal Solution
3.1 Identification of Common Pathogens
(T-J) disease (black sunken spots) and root rot disease (accompanied by a foul odor) need to be treated differently. It is recommended to check the underside of leaves weekly and isolate any spots with a diameter exceeding 3mm.
3.2 Rotational Use of Fungicides
Alternately use mancozeb (protectant) and pyraclostrobin (therapeutic), spraying once every 7-10 days for three weeks. Focus on spraying the stem nodes and the surface of the potting soil, avoiding drug accumulation that may lead to resistance.
Through three-dimensional governance of environmental control, root system repair, and disease prevention, combined with monthly application of bamboo vinegar solution (diluted 1000 times), effectively prevent the recurrence of black stems. Remember to rotate the pot regularly to ensure even light exposure, and use nutrient solution with an EC value of 1.2-1.5mS/cm to keep your Epipremnum aureum in the best growing condition.