What are the reasons for black stems in roses?
An introduction to the reasons for black stems in roses and the solutions, here is a detailed introduction.
Enthusiasts for rose cultivation often encounter the problem of black stems in roses. What are the causes of black stems in roses, and how can they be prevented and treated?
Common reasons for black stems in roses
Everyone knows that roses are prone to diseases and pests, so enthusiasts for rose cultivation usually do regular disease and pest prevention. However, there are always a few weak rose plants that easily show signs of black stems. What exactly causes this? The following are common reasons for black stems in roses.
1. Severe infection of black spot disease
Black spot disease is one of the most common diseases in roses. If a rose branch is infected with black spot disease and not treated in time, severe black spot disease will manifest as dark brown spots on the branches, which look similar to black stems.
Severe black spot disease can affect the growth of roses, but it does not threaten the life of the plant as black rot does. Usually, timely application of pesticides can treat the infection, and the affected branches can still be retained.
2. Infection with black rot bacteria
Roses are most susceptible to black rot in hot and humid environments, leading to blackened,腐烂, and withered branches. Especially in summer, high temperatures and poor ventilation in the inner branches make them more likely to be infected with black rot and wither.
For some weak rose plants, due to poor growth and reduced resistance, they are very susceptible to infection by black rot bacteria. Therefore, for weak rose plants, attention should be paid to water control and disease and pest protection. When black stems appear in roses, if they occur at the top or middle of the branches, the diseased part can be completely cut off, along with a section of healthy branch, and fungicides should be sprayed.
What are the reasons for black stems in roses?
However, if the black stem starts from the root, it is more difficult to handle. Usually, the rose plant needs to be removed from the pot, the blackened branches and roots cut off, and then the wound treated with a fungicide powder before planting again.
3. Black stems caused by fertilizer damage
In fact, many times, black stems in roses are caused by improper fertilization. The season when black stems in roses most commonly occur is the transition from spring to summer to late summer. During this period, temperatures are still relatively high, and the growth status of roses can vary greatly.
Rose varieties with good heat resistance continue to grow in summer, and fertilization is usually not a problem. However, some rose varieties with poor heat resistance may already show signs of slow growth at the transition from spring to summer, and their tolerance to fertilizers is relatively low. If we continue to fertilize at this time, it can easily cause fertilizer damage.
Most of the time, fertilizer damage in roses manifests as yellow leaves, but in high temperatures, excessive use of fertilizers can cause black stems directly. Therefore, it is best to avoid applying fast-release fertilizers to roses during high temperatures. For specific fertilization methods at different stages of rose growth, you can refer to the book "How to grow roses from scratch to bloom."
For black stems caused by fertilization, there is often still a chance to save the plant. For example, if it is caused by organic or slow-release fertilizers, it is recommended to remove the fertilizer and flush the roots with a large amount of water. If it is caused by water-soluble fertilizers, you can directly flush the roots with a large amount of water, while retaining the black stems. Usually, if discovered in time, the plant can be saved.
The above content on the reasons for black stems in roses and the solutions provided by the Green Plant Enthusiast website is for everyone's reference and operation.