What causes the black stem after pruning a Chinese rose
Main content introduction: This article discusses the reasons behind the black stem that occurs after pruning Chinese roses, and the following is an introduction by the editor.
What causes the black stem after pruning a Chinese rose
Chinese roses are very beautiful, and many hobbyists grow them. In maintaining them, one essential step is pruning. However, Chinese roses not only enjoy pruning but can also easily develop problems if pruned improperly.
Look at this pot of Chinese roses that I have pruned. Now it has developed a problem - the stem has turned black. So, where is the problem, is it related to pruning? There is some correlation, but it cannot be entirely blamed on pruning. Let's discuss why Chinese roses often develop this black stem issue after pruning.
1. The pruning tools were not sterilized
During pruning, if the tools are not sterilized once, twice, or thrice, it might not cause a problem. But after ten cuts, there will likely be one or two instances where a problem occurs, which is that bacteria can infect the branches and cause the decay to gradually spread downwards, resulting in the entire plant developing a black stem.
However, this type of black stem will not cause the roots to rot. At most, it will lead to a section of the branch turning black, which many hobbyists have experienced deeply.
2. Watering excessively after pruning
Other than bacteria entering through the wounds, is there anything else that could cause the Chinese rose to develop a black stem? There is another factor related to pruning.
This is when excessive water is poured on the plant after pruning, leading to excessive accumulation of moisture in the branches. This causes the internal tissues to necrotize directly, eventually resulting in a black stem. This phenomenon is blackening from bottom to top.
3. Over-fertilizing
This can also cause the branches to turn black. This type of issue can be controlled, so we should try to control it by applying a light fertilizer after pruning. That means using a light fertilizer and not using too heavy a fertilizer.
This branch turned black due to water issues after pruning, and then I placed it in an open environment where it rained for two days. For such Chinese roses with blackened branches, we can simply pull them out. When pruning, it's best to sterilize the pruning tools, using metalaxyl to sterilize them, which provides a fairly ideal result.
The above is a comprehensive explanation about the causes of black stems after pruning Chinese roses, and I hope it helps you.