He mildew It is one of the diseases that most affect plants, both horticultural and ornamental. In the case of the rosebush, this is a bush that, unfortunately, is also unable to resist its attack.
Therefore, it is important to know how to identify the symptoms it causes, and also, how it is treated. And it is that the mildew of the rosebush is not a potentially serious disease, but we must be aware and apply some treatment as soon as the first damages appear.
What is mildew?
El mildew It is a disease caused by oomycetes such as Phytopthora, Plasmopara or Peronospara, the latter being the one that attacks rose bushes. like mushrooms, these feel very comfortable in humid and warm environmentsso they usually appear after an episode of rain that has occurred during the spring or summer.
In addition, if the plant is already weakenedeither because it has received excess water, or because the soil in which it grows does not allow the roots to be well aerated, which happens in very heavy and compact soils, it is easier to end up with mildew. In other words: if you have your needs covered and the soil is well drained, it is rare for you to get sick.
How does it affect the rose bush?
Pests and diseases of rose bushes
The symptoms of mildew in the rosebush are the following:
- First, yellow spots appear on the upper surface of the leaves which over time turn brown. In addition, later they are covered with a gray powder.
- If the rose bush is young and/or has tender stems, not lignified, it can also end up with damage to themshowing these small yellow spots.
In very serious cases, the diseased rosebush will end up without leaves, so it will take a long time to sprout again. Luckily, there are things we can do to give you a chance to move on.
What is the treatment for rose bush mildew?
If you suspect that your rosebush has mildew, what you have to do is treat it. In the market there are chemical products, and others that are ecological. For example, when it comes to chemicals, the most effective are those containing: mancozeb, fosetil (on sale here!) or copper oxychloride. And if you opt for natural products, the following are very interesting: nettle extract (for sale here!), or the extract of horsetail (Equisetum) that you can buy here!.
But regardless of which one is to be applied, we have to follow instructions that we will find on the packageOtherwise, the remedy could be worse than the disease, as we say in Spain.
Of course, in addition to this, you also have to do something else:
Watch the irrigation
As we said, the oomycetes They appear when it has rained a lot and/or constantly, but also if we have watered the rose bush a lot. For this reason, it is important to control irrigation. Y This can be done in a very simple way: before adding water, insert a wooden stick to the bottom. Then, when you extract it, you will see if the soil is wet or if it is dry.
If you have your rose bush in a pot, it is better not to put a saucer under it to prevent the roots from rotting.
Do not plant it on heavy and compact land
This is valid whether you are going to have it in a pot or if you prefer to plant it in the garden. The rose bush is a fairly resistant plant, but if we put it in a very compact soil, it could end up suffering from mildew or other diseases.
For this reason, the ideal is to have it in a rather light soil and, above all, that it has good drainage. Thus, if it is going to be in a pot, we will put a universal substrate that contains perlite, and if it is going to be in the garden, first of all we will have to make a hole of about 40 x 40 centimeters, fill it with water, and see if it is is rapidly absorbed; if so, then we will plant it, but if not, we will fill it with a mixture of peat and perlite in equal parts.
Don’t water it from above
Watering the plants from above can only be done if the air humidity is low and they need to be high, or if it is very hot and we want to cool them down. But In any case, it will be done when the sun no longer shines directly on them, otherwise the leaves will burnthey will weaken, and mildew could appear if we also do it frequently.
Apply fungicide if it’s going to rain
You can use products suitable for organic farming, such as nettle slurry, or some systemic fungicide. But without a doubt treat the rosebush, especially if we see that it is weak, can help prevent you from getting downy mildew.
The mildew of the rosebush can kill the plant, but if we detect it in time, it will surely recover.