Roses are very common flowering plants to grow in a garden. However, they can be quite difficult to grow due to intensive and ongoing management. Although growing roses in a greenhouse reduces exposure to pests and diseases, white spots can still develop on roses.
Most of the time you can observe white spots on the surface of the flower, on leaves or stems. However, on some occasions they might not be visible at all. So, don’t forget to check under the leaves. To know how to get rid of white spots on Roses you need to determine what is causing them.
Predominantly fungal disease or insects activity cause white spots on Roses. In this post we will tell you how to solve this problem based on its cause. We will talk about the natural solutions and commercial options available, so you can choose how to get rid of white spots on Rose leaves.
So, how to get rid of white spots on rose leaves?
Generally, if white spots are results of fungal disease or insect infestations, use Neem Oil Fungicide and Insecticide and spray plant leaves once early in the morning every 7 to 10 days. Also, you can spray Rose leaves with a solution of baking soda, neem or horticultural oil and dish soap.
#1 – Spray Leaves With Neem Oil Fungicide
Cause: Fungus Podosphaera pannosa affects all aerial parts of the plant and produces spores that spread the disease. The disease is called Powdery Mildew and results in white spots on leaves or white coating on leaves, stems, flower stalks and petals.
Solution: Spray Neem Oil Ready-To-Use Fungicide on the top and undersides of the affected leaves. Make sure that leaves are completely covered with the solution. You can also spray it on unaffected leaves for prevention.
What time of the day do you need to spray Roses? Spray Roses with Fungicide to get rid of powdery mildew early in the morning. That way you will make sure that the rest of wildlife like bees, butterflies and bird are not active, hence you won’t cause them damage.
How often should you spray solution on roses once you notice mildew? Spray fungicide solution on Rose leaves that are both affected and not affected by powdery mildew early in the morning as soon as you noticed the problem. Then spray again on the 7th or 10th day. Although, you need to reapply the spray if it rains.
Spray on a dry, calm day. Don’t spray in the middle of the day especially in summer months. In summer spray very early in the morning or in the evening. You can spray on a cloudy day in summer . Always check the label for application instructions.
However, if only a few leaves are affected on one or two plants, cut them off and dispose in the trash and not a compost pile. Also, remove the fallen leaves from the ground. Make sure to sterilize pruners with rubbing alcohol before and after pruning.
#2 – Wash Bugs Off Rose Leaves
Cause: Sometimes insects look like white spots on Rose leaves. For example, some species of aphids are white in color. Moreover, scale insects can deposit their eggs on the underside of leaves that are covered with waxy fibers. Finally, leafhoppers feed on the underside of Rose leaves resulting in white spots.
Solution: If you identified bugs early, you can wash them off leaves. Use a hose end water sprayer and spray leaves and blooms well. The spray should be powerful enough but not too strong to avoid damaging the blooms or defoliating the plant.
In the early stages you can pick off bugs by hand and feed them to chickens, for example. Alternatively, you can leaves them on the ground and other insects will prey on them. A light tapping of the bloom or leaves is enough to knock bugs on the ground. Do it a few times a day.
Also, roses are able to withstand attacks of leafhoppers. They have natural enemies too, so most of the time natural process will prevent any damage. If your Roses are affected by scale insects, prune and dispose affected branches.
Pick them off of leaves and blooms by hand. Alternatively, if number of scale insects is low, dab on them with an alcohol-soaked cotton swab or neem oil leaf polish. Aslo, Neem oil fungicide and insecticide will control aphids and scale insects. Although it may not kill leafhoppers, it will discourage feeding.
#3 – Spray Leaves with Baking Soda, Neem Oil And Dish Soap Solution
Rather than using fungicides and insecticides you can make a solution from natural products. It is as effective and is safer for the environment. Remember, that we don’t want to cause harm to beneficial insects and pollinators.
Take 3 tablespoons of baking soda and add mix it in a gallon of water. Then, add 1 tablespoon of neem oil or horticultural oil. Finally, mix in 2 drop of dish soap. Baking soda will kill fungi because it creates alkaline environment on the leaf. Fungal spores need a pH of 7.0 to around 8.0 to survive and spread.
Adding neem or horticultural oil will help spray to stick to the surface of the leaf. Moreover, oil coats and smothers the fungi. Oil will also prevent insects from feeding, larvae from maturing and can also kill insects. It coats the breathing holes on insects body, so they die from suffocation.
Adding a few drop of dish washing soap will help to mix all the ingredients together. Also, applying dish soap helps mix to spread and stick to the leaf or stem surface. Make sure to spray the solution to the top and to the lower leaf surfaces.
When plants are changing color they try to signal that you are doing something wrong. For example, if plant leaves are turning white, apart from fungal diseases they can get low light or have ozone damage. If plant leaves are turning yellow, you might be overwatering. That is one of the main reasons why greenhouse plants are dying.
So, to get rid of white spots on Rose leaves you need to determine what is the cause of the problem. If that’s powdery mildew and it affects a few plants, cut off and dispose infected leaves. Spray the leaves early in the morning with Neem Oil Funcigide every 7 to 10 days during growing season.
If white spots are aphids or scale insects, try picking them off by hand or wash them off leaves. You can also use Neem Oil Insecticide to get rid of bugs. It will not kill leafhoppers but will discourage them from feeding. Finally, you can make a baking soda solution and spray your Roses.
What are you using to get rid of white spots on Rose leaves? Let me know in the comments section below!
Happy Growing 🙂