What to do if Chinese roses have red spiders?
The internet introduces knowledge about Chinese roses with red spiders, let's take a look together.
Recently, many southern flower friends have consulted about the problem of red spiders in Chinese roses. The other day, when watering, I also found that my large flowering wall of Chinese roses has been infested with red spiders. The treatment of red spiders is relatively difficult and requires persistent management. So today, let's talk about the prevention and control of red spiders.
Prevention methods for red spiders in Chinese roses
1. Avoid overcrowding
When arranging potted Chinese roses, try to space them out, not拥挤 together. Leave some distance between each pot of Chinese roses, and keep the branches and leaves from intersecting with each other. This not only ensures sufficient ventilation but also prevents the spread of diseases and pests between plants.
2. Timely remove the old leaves at the bottom
In spring, after the first bloom of Chinese roses, it is important to promptly remove the old leaves and blind branches at the bottom. Red spiders usually start from the bottom, so removing these leaves close to the soil can block the infection route of red spiders to some extent.
3. Pay attention to rinsing the leaves when watering
In the dry weather of the southern region, the frequency of watering is relatively high. Outdoor potted Chinese roses often need to be watered once or even twice a day. In such cases, we can use a curved spray head to rinse the back of the Chinese rose leaves when watering.
This way, it can increase humidity, as red spiders dislike dampness, and the water flow can also wash away the red spiders that have climbed onto the leaves, which is very helpful in抑制 the development of red spiders.
4. Focus on spraying pesticides on the surface of the potting soil
Merely relying on physical control is not enough, and regular pesticide prevention is also very important. According to different seasons and the occurrence patterns of diseases and pests, a comprehensive prevention and control plan should be implemented. Specific methods can be referred to in the book "How to Grow Chinese Roses from Scratch."
One thing to note is that many flower friends only spray the front of the Chinese rose leaves when applying pesticides, or even just the upper leaves, because it is simpler and more convenient to spray the upper leaves of potted Chinese roses with liquid fertilizers or pesticides.
However, the infection route of red spiders usually starts from the bottom, so when applying pesticides, you must use a curved spray head to spray the back of the bottom leaves of Chinese roses, and also focus on spraying the surface of the potting soil, as many red spiders may be washed off and fall onto the surface of the potting soil. Therefore, spraying the surface of the potting soil with pesticide solution is an important detail.
Once Chinese roses are infected with red spiders, the management must be persistent. You can't just spray once and be done with it. If you love Chinese roses, you must have the determination to fight for your beloved Chinese roses to the end.
Methods for controlling red spiders
If it is potted Chinese roses, it is best to use a combination of physical control and chemical control.
① Rinse the leaves with water
When red spider symptoms are found on the leaves of Chinese roses, immediately check the back of the leaves. If you see dirty dots, they are red spiders. Infected leaves should be removed immediately and sealed in a plastic bag. Do not throw them away randomly to avoid spreading to other plants.
Then use a high-pressure water gun or spray bottle to spray water on the back of the Chinese rose leaves, allowing the water flow to carry away the red spiders. Note that before rinsing, it's best to cover the surface of the potting soil with a plastic bag to prevent red spiders from falling into the soil.
② Wipe with alcohol
After rinsing the leaves with water, place them in a well-ventilated area. Once the leaf surface is dry, wipe them with an alcohol solution. Dilute 75% alcohol 200 times, dip a cotton ball in it, and wipe the leaves of Chinese roses, focusing on the back of the leaves. Since rinsing may not remove all the red spiders, wiping with alcohol is more reliable. Alcohol can also act as a disinfectant.
After wiping the leaves with the alcohol solution, spray the remaining solution on the surface of the potting soil, but do not pour it into the roots.
③ Spray acaricides
Basically, after the above two actions, the number of red spiders has been greatly reduced. Now, give them a more powerful attack by applying acaricides.
Drugs such as damycin, jinmanzhi, aikacan, hongsasha, huolongzhai, and abamectin can be used to treat red spiders. You can refer to the table below.
After wiping the leaves with an alcohol solution in the evening, spray a comprehensive acaricide the next day, including the back, front of the leaves, and the surface of the potting soil, as well as other uninfected Chinese roses and other plants.
When spraying Chinese roses with red spiders, be thorough. The concentration of the medicine can be lower, but make sure to spray thoroughly. Try to spray all areas, especially in the evening when the temperature is low, as the medicine will stay on the leaves longer and have a better effect.
With these three consecutive moves, red spiders will basically be completely gone. To prevent any遗漏, after 5-7 days of applying the medicine, switch to another two types of medicine and apply again, while also taking the preventive measures mentioned at the beginning of this article to prevent re-infection with red spiders.
We can handle potted plants according to the above methods, but what about those planted in the ground? Indeed, when there is a large-scale infection, it is impossible to wipe each leaf individually. The only option is to persist in rinsing and applying pesticides.
Rinse the leaves twice a day, early in the morning and in the evening, and apply pesticides every 5-7 days, using two types of drugs alternately for 2-3 times, which can also cure the problem.
The above is a complete introduction to what to do if Chinese roses have red spiders. I hope it can be helpful to you. Don't forget to check out more flower cultivation experience and common sense!