Rosemary is an evergreen shrub of Mediterranean origin with a remarkable fragrance. It has high resistance to various injuries because it can adapt to climate extremities. However, that doesn’t mean that it can tolerate frequent adversities in climate. Mostly, gardeners face a lot of problems when they grow rosemary.
They can often find white spots on the leaves of rosemary plants. It is a fact that plants showing such symptoms are not in good health. Considering that, your rosemary plant is showing white spots, you must try to figure out the reason before you start treating the cause.
Here are the most common reasons why you may find white spots on rosemary plants:
1. Cold- water spots
Coldwater spots can mostly occur in indoor conditions. If you use water directly from the tap, a shock is created that can cause the palisade leaf cells to tear down and leave behind a white callous. Sometimes, minerals released from tap water can get piled up and show up as white-colored spots on the leaves.
Normally, white spots don’t cause any harm to the plant. But you just can’t get rid of these spots without removing the affected leaf. So, you might think about the treatment of white spots on rosemary.
You shouldn’t make use of cold water directly from the tap. This can help in reducing the white spots. You can follow many procedures. All that you need to do is put the potted rosemary within a tub with some inches of water. The drainage gap will let the water soak up without causing any shock to your rosemary plant. If the minerals get accumulated, you can make use of a water filter or filtered water on the plants.
A diluted solution of vinegar can reduce the visibility of these mineral accumulations. Here is a recipe you can try using distilled water, and white vinegar. Mix vinegar with distilled water in a 1:1 ratio. Start spraying this solution on your plant.
2. Pest infestation
Pests are regular enemies of these plants. Rosemary is also included in this category. Because of pest infestation, plant leaves start showing white spots. The yellow-white spots are an outcome of this. Mostly the sucking insects cause this injury. Pests like the spider mites, and leafhopper, are little evils in this situation. They can suck out the sap from the bottom part of leaves and thus create tiny white spots on your rosemary plant.
Sometimes, striplings can also be seen on these leaves. There are many other insects such as scale insects, aphids, and mealybugs that can leave a sticky white material on the rosemary plant after infestation. These substances can increase the fungal growth in rosemary plants.
First, you need to start by giving a good splash of water to your plants. This will help it in getting rid of cotton residue and saps. The concentrated form of Neem oil spray can also be a good choice for these pests. Generally, a 2% concentration is considered safe for edible plants. You must make sure to follow all the instructions mentioned on the package.
There are many low-cost options like insecticidal soap and others. You can use any one of these options or use all of them alternatively. Start by applying Neem spray, then spray insecticidal soap after a few days. A small amount of rubbing alcohol can be used for removing any insect-based residue decreasing the risk of pathogen attack in the future. If these methods don’t seem to be effective enough, simply use a pesticide that is created for indoor plants.
3. Fungal attack
Rosemary is a plant that is very vulnerable to fungal attacks. This may be seen in different forms in the plants and is the main cause of fuzzy outgrowths and white spots. You may notice some powdery flakes on the rosemary plant. These happen because of powdery mildew. This disease is very severe and can make your plants weak even if it doesn’t kill them. It is easy to find out whether your plant is attacked by powdery mildew.
You will find a coating of white powdery and it can be seen in this situation. This powder is created by the fungi, which spreads quickly to other parts of the plant. So, you must treat this disease as soon as you can.
Downey mildew is also a kind of attack where the white spots can be seen on the lower part of the leaves of your rosemary plant. Greyish-white mold on the dried rosemary appears in humid and wet conditions. They may infect the fresh leaves of your rosemary plants and their woody stems too. Mold development in rosemary plants usually can be seen as white or grey fluffy spots. The growth of fungus can destroy all the flowers of your plant.
The solution to fungal diseases remains the same for almost all plants. But you must bear in mind that rosemary is an herb that can be eaten. You must follow a good treatment procedure keeping in mind this herb is edible. All that you need to do is to rub the infected part of the leaves in a careful way to get rid of the leftover ones.
Instantly, remove a shed lead that is affected by the fungus to prevent transmission of soil. If you’re still not able to control this, it is better that you start using a fungicide created for edible plants like rosemary.
If you now see white spots on your rosemary plant, don’t overthink it too much as the reasons is already discussed above in this post. You can be sure that the cause of white spots is anyone of these mentioned above. Just confirm the cause before you start treating it. You need to follow the right treatment process as even a single wrong step can make the entire process go wrong. Be very careful about applying the solution just as it is mentioned against the cause.