If your plumeria leaves developing white spots then something is going wrong. You need to figure out the causes before it causes any further harm.
Powdery mildew the most likely cause of white spots on plumeria leaves. In addition, oedema, excess sun exposure, and fungal infection may cause this problem. The appearance of spots will help you identify the problem and then take measures to fix it.
In this article, I will go into detail about all the possible causes of white spots on plumeria leaves. In addition, I’ll walk you through how you can fix the problem.
Why Does My Plumeria Have White Spots?
Oedema is caused by overwatering your Plumeria plant. The roots bring too much water in and it cannot all be used so it starts being pushed out through the leaves.
The leaves will develop white or yellow spots after the water is pushed out because they are damaged. It is mostly visible on the underside of your Plumeria’s leaves.
How to Fix
Check your Plumeria before you water it to be sure it has dried out completely. Adjust your watering schedule if you notice it is still wet when it is time to water again.
Watering your plant only when it’s dry will decrease the likelihood of oedema occurring and causing the white cork-like spots on the leaves.
If you notice white powdery looking spots on the top sides of your leaves then your Plumeria plant has powdery mildew.
The spots may also appear on the underneath of leaves and on the flowers too. It looks almost like your plant is dusty and you can wipe it away but it will reappear.
If it’s not treated an extreme case can begin to turn the leaves yellow and slowly kill the plant. Powdery Mildew occurs the opposite of most mildew.
It thrives in dry but humid conditions and lower light settings. For outdoor plants, you will see it occur mostly in late spring and early summer when the temperatures start to warm and humidity increases.
How to Fix
To prevent powdery mildew plant your Plumeria in a location that will be mostly sunny or sit your indoor plants closer to the light source.
Water your plant frequently to combat the dry conditions that encourage powdery mildew growth.
It is best to overhead water in the morning so that the plant has time to dry before it’s cooler in the evening. And try not to overlap plants creating a shady environment for your plant.
If you already have signs of mildew then start treating your plant by dissolving a teaspoon of dish soap and a teaspoon of baking soda in a gallon of water. Spray your plant thoroughly with the mixtures and repeat as necessary.
If you prefer you can buy an antifungal spray at your local hardware store or plant nursery. Follow the directions on how to use the product for your specific plant.
Plumeria’s require at least 6 hours of full sun a day to grow properly. Indoor Plumeria plants should be placed near a light source for at least 6 hours a day.
During the spring and summer your indoor Plumeria can go outdoors but introduce it to the sun gradually.
Putting your indoor plant into the sun for the full 6 hours the first day can cause the leaves to get white spots known as sunburn.
How to Fix
Slowly introduce your indoor Plumeria to the outdoor sun by starting it in partial shade and increasing its sun time.
This will give the plant time to adjust to its new conditions without burning. Make sure to adequately water the plant when putting it outdoors because it will dry quickly in the sun.
Keeping it well watered will help to prevent sunburn also by keeping the leaves moist.
If you have leaves that are spotted with a white sunburn you can trim them away and give your plant more time indoors away from a direct light source.
Plumeria prefers temperature between 65°F and 80°F (18-27°C.) and mild weather. They are tropical plants so they can tolerate warmer temperatures rather than cooler ones.
In the winter Plumeria will begin to drop their leaves and go dormant. The leaves may start to develop white or yellow spots before the leaves drop due to temperature fluctuations.
How to Fix
You will need to protect Plumeria from cold weather by bringing them indoors during the cold months.
When temperatures soar above 80°F ( 27°C.) you will need to water them more since they are using their water quickly in the higher temperatures.
Keeping your Plumeria in warm temperatures will prevent the leaf drop from temperature stress.
You might have noticed white spots and webbed looking spots on the leaves of your Plumeria. Or maybe you saw fuzzy white spots on your Plumeria plant. Either one could be a sign you have bugs living in your plant.
- Spider mites create a webbed look to the underside of the leaves and feed off the juices of a plant to survive.
- Mealybugs live underneath the leaves near the veins and feed on the plant leaving behind a white sticky honeydew substance.
- Thrips look like tiny white dots on the leaves and also attach to the flowers. They leave behind silver stripes after they’ve fed from the plant.
- Leafminer babies tunnel and eat through the inside of the leaves which creates a white spotted pattern all over each leaf.
- The Leafhopper can cause a muddled white look to your leaves as it sucks the sap out of your leaves. If you notice any of these signs then you have a pest and once you’ve determined which it is I can help you get rid of them.
How to Fix
- You can prevent spider mites by misting the underside of your leaves regularly. If you’ve already noticed them living in your plant you can give it a really good rinse making sure to get every leaf and wipe them off gently. It may take more than one rinse to get rid of them all.
- If you have mealybugs you should begin by wiping each leaf down with a cotton ball that was dipped in rubbing alcohol to remove any bugs you see. You can also spray down the entire plant with a gallon of water mixed with one tablespoon of dish soap to kill them.
- Thrips are a little more difficult to get rid of and require purchasing Neem Oil or an insecticide soap. You will want to follow the product’s instructions and treat them frequently until you no longer see them on your pants.
- Leafminers will require White Oil or Neem Oil. You can make your own White Oil by combining one teaspoon of vegetable oil, one teaspoon of dish soap, and two cups of water. Spray the plant generously but don’t overdo it.
- The Leafhopper is a relatively new pest for Plumeria plants. Prevent infestation by cleaning up dead leaves at the base and trimming away any dying leaves. Hosing down your plant regularly can discourage eggs from being laid. You can also use an insecticide to remove them from your plants.
Black Sooty Mold begins with the white spots you see insects causing on your plants when they leave behind their honeydew secretions.
The honeydew left behind creates the perfect environment for the black sooty mold to thrive. Eventually, your plumeria will have black spots on leaves.
The white honeydew spots will start to turn black looking like they are covered in soot as the name implies.
How to Fix
To prevent black sooty mold you would want to catch the insect infestation in the early stages before the white sticky spots on your plant become the breeding ground for the mold.
You would need to get rid of the insects to prevent the honeydew from being left behind on your plant.
Plumeria plants are heavy feeders in the spring and summer requiring a lot of fertilizer. They need more phosphorus and less Nitrogen.
Lack of Nitrogen or using an unbalanced fertilizer can cause yellow and white spots on the leaves of your plant. The entire leaf will eventually turn white and die.
How to Fix
Fertilizing your Plumeria weekly during the spring and summer will prevent the yellow and white spots.
You will want a fertilizer with higher phosphorus levels and follow the directions for proper use.
Do not overwater after fertilizing because it will wash away the nutrients your plant needs.
Poor Air Circulation
Poor air circulation around your Plumeria plant can cause it to develop rust. Rust is a spotted look on the underside of the leaves.
Wet, overly humid, and bad circulation create the right environment for rust fungus to attack your plant.
How to Fix
- Plant your Plumeria in a location where it will receive enough sunlight to dry it
- Grow it in an area with good circulation around the plant
- Move your plant to a new location if you notice rust forming
- Trim away any affected leaves
If your Plumeria is starting to show white spots or yellowing leaves along with wilted stems it may be caused by overwatering. Plumeria likes a lot of water but doesn’t like to sit in water.
Sitting in water causes the roots to rot and they can no longer bring nutrients or water to the stems and leaves. This will cause the leaves to change colors and the stems to start wilting.
Underwatering your Plumeria will also cause wilt but the leaves will begin to change colors and look crispy and dry. The plant will drop its leaves and flowers too.
How to Fix
To prevent overwatering make sure the plant is dry before you water again. You can check by sticking your finger into the top of the soil.
When you water, do it thoroughly and let your plant drain excess water away to prevent root rot.
Underwatering is easily fixed by giving the plant a good soaking in a well draining pot.
Once it spruces itself back up you’ll want to make a watering routine to ensure it doesn’t dry out again.
If temperatures dip below freezing your risk getting white crystallized spots on your plant known as frost.
You will only notice frost on your outdoor Plumeria leaves in the morning right after the sun comes up when the weather is colder.
How to Fix
It is recommended to bring your potted outdoor Plumeria inside if temperatures are going to drop below 50°F (10°C) to protect them (Source: University of Florida).
You can also protect your Plumeria from frost by draping a large cloth or plastic over the plant and removing it once the temperature starts to warm up in the afternoon.
If you already have frost damage you will need to trim away all of the damaged leaves and stems to protect the rest of the plant.
How to Prevent White Spots on your Plumeria Leaves
- Stick to a proper watering routine as to not cause your plant to drink too much too fast and create burst points in the leaves.
- Fertilize your plant regularly during its growing season with the correct ratio of nutrients.
- Slowly introduce your indoor Plumeria to the outdoor sunshine to prevent sunburn spots.
- Protect your Plumeria from frost during the colder months by bringing it indoors.
- Check every watering to make sure there are not any pests creating a home in your plant.
Frequently Asked Questions
- Why do my Plumeria leaves look powdery?
If you notice a powdery substance on the tops of your Plumeria leaves that resembles dust it could be powdery mold. You can treat it by creating a spray made of a teaspoon of baking soda, a teaspoon of dish soap, and a gallon of water.
Spray it liberally on your affected plants. Use as often as necessary. To prevent reoccurrence move your plant to a sunnier location and water frequently to prevent the humid, dry, and shady conditions that encourage powdery mildew.
- Why does my Plumeria leaves have orange and gray-white spots?
Overwatering can cause the Plumeria plant to soak up water too quickly. It can’t use all of the water it took in through its roots so it pushes it up through the leaves.
It causes the leaves to bubble in small spots that turn to white or orange spots on top of the leaves. This is caused by a process called Oedema. To prevent it, only water your plant when the soil is dry and water in a pot with good drainage.
- How can you protect your outdoor Plumeria during cold weather?
Plumeria plants do not thrive in temperatures below 50°F and will frost over if left in below-freezing temperatures.
To protect them during cold weather bring them indoors. If this isn’t possible, you can cover your plant with a large cloth or plastic to protect it from frost during the colder months.