As a deciduous plant, it’s quite normal for plumeria (also known as frangipani) leaves to turn yellow and drop after the growing season. But, there are instances when yellowing has something to do with other causes.
Plumeria leaves turning yellow due to overwatering, underwatering or nutrient deficiency. Besides root rot, fungal diseases, insect infestation, excessive feeding, low humidity can also be responsible for this issue. To fix the problem, water the plant when the top 1-2 inches of soil feel dry, provide adequate light, apply fertilizer, and insecticide to control pests.
In this article, we will discuss all the other possible reasons why plumeria leaves are turning yellow.
Causes of Plumeria Leaves Turning Yellow
Here are the common reasons why plumeria leaves are turning yellow. Remember that each cause may be related to the other.
Overwatering Leads to Root Rot Disease
Plumeria plants do well in moist soil. It can even tolerate drought to some extent. Once you over-apply water and the soil becomes soggy, the plant will have the tendency to develop yellow leaves.
Overwatering is the main culprit behind root rot. The waterlogged soil limits the oxygen intake of the roots. This, in turn, hampers one important metabolic process known as respiration.
Solutions:
- Skip watering for a week or so.
Since the soil is soggy when it’s overwatered, you have to stop watering the plant. Let it dry for a while. This will help the roots recover from the damage brought by excess watering.
- Expose the plumeria under bright light.
Plumeria is naturally a sucker for bright light. If it’s overwatered, exposure to the bright light condition will help hasten the moisture loss.
- Ensure good drainage.
You can do this by poking the holes beneath the pot to remove blockages. If drainage holes are not present, you have to transfer the plant to another pot or dig holes in the existing one.
- Transfer to a new pot.
There are times when there’s a need to change the potting mix. In that case, you will have to repot your plumeria. Choose a well-draining potting mix this time.
Too Much Direct Sunlight
You can grow Plumeria plants under varying light conditions be it full sun, partial sun, or partial shade. Plants placed indoors are accustomed to partial shade.
If you transition them to full sunlight right away, they may suffer from direct exposure to strong light intensities.
Too much direct sunlight can scorch the leaves. This results in discoloration such as yellowing or browning.
Solutions:
- Bring your plant back indoors.
To avoid further damage, it’s best to bring your plumeria indoors. The scorching sun is clearly not good for its leaves. Place it back in its indoor location.
- Expose your plumeria to direct sunlight only in the morning.
If you wish to expose your sun to direct sunlight, make sure that you do it in the morning. Morning light is less intense and less destructive. After a couple of hours, you may bring it back inside.
- Add additional shade around your plant.
You can do this by placing taller plants around the plumeria. The additional foliage shall block the excess sunlight.
Inadequate Watering
Another reason why the plumeria leaves are turning yellow is underwatering. The lack of water in the soil will cause drought stress. Water and nutrient transport will be affected. The plant may show curling leaves symptoms.
Aside from that, the roots will incur damage as they will be forced to exert extra effort in looking for water. The roots may also end up getting shriveled.
Solutions:
- Water the soil thoroughly until saturated.
Underwatered plumeria needs thorough watering. Pour water into the soil until excess water drips and seeps out of the drainage holes.
- Place the plant under partial shade.
Under a partially shaded condition, the transpiration rate of the plant will slow down. Thus, we can avoid rapid moisture loss.
- Increase watering frequency.
If your plant is not receiving enough water, you can compensate for what is lacking by increasing the watering frequency. Water the plants enough for the soil to be moist but not soggy. Just ensure the drainage is functioning well.
Mineral Deposits
If you’re using hard water on your plants, then the soil must have accumulated mineral deposits. Hard water contains substances such as calcium carbonate, sodium, and iron. These deposits will create a drought condition in the soil.
The white crust will begin coating the surface of the soil. The tissues of the plants will burn and die. These are the yellow spots you’ll see on the leaves.
Solutions:
- Repeatedly flush the potting soil with water.
Flushing out will help get rid of the minerals that accumulated in the soil. Pour water from the top until the water is seeping out of the container. Do this over and over again allowing a few hours of the interval until the white crust is gone.
Use good quality water such as pure water, filtered water, or rainwater. Make sure that no excess water remains in the pot after doing this.
- Ensure good drainage.
One reason why minerals accumulate is the lack of good drainage. This usually happens when you plant your plumeria in a pot with no holes. The water gets intact in the container along with the minerals contained in it.
- Repot the plumeria plant.
Repotting is a good way to replace the soil with a fresh one. Through this, you’ll be able to completely get rid of the mineral deposits. Use well-draining soil as a new medium for your plumeria plant.
Root Rot
Root rot is common damage that potted plants experience. The limited space and amount of medium make it easy for water to flood the roots. Once water replaces the oxygen in the pore spaces, the roots will drown and die.
Another possible cause of root rot is a soil-borne disease. If you’ve used previously infected soil, there’s a high chance that your plant will develop that disease. The first site of infection is the roots.
Symptoms of pathogen infection include leaf discoloration such as yellowing.
Solutions:
- Stop watering for a while.
Overwatering is one obvious reason for root rot. If the soil is getting soggy, it’s time that you stop watering for a while. Wait for the excess moisture to evaporate so the soil will dry out.
- Repot using a fresh set of potting soil.
Repotting addresses both the problems of overwatering and soil-borne diseases. Replace the soil with a well-draining and sterilized potting mix. Also, trim off the damaged roots to prevent the spread of damage.
- Apply chemicals to address soil-borne diseases.
One of the ways to control pathogens is by the application of fungicides. Copper sulfate and elemental sulfur are the chemicals present in fungicides that can lower the disease incidence on your plumeria.
However, you have to know exactly what type of pathogen is attacking your plumeria. This will help you choose the right type of fungicide to use.
Pest Infestation
Insects can work subtly when they attack the plants. Although plumeria is generally disease-free, there are times when they get vulnerable. They might be the reason why the leaves of your plumeria are turning yellow.
Here are the common pests that you’ll most likely encounter in plumeria plants.
| PEST | CAUSE | SYMPTOMS |
| Scales | Insert their needle-like mouthparts into the plant tissues Sucks the sap and contents of the tissues | Leaves turn yellow and later drop Presence of honeydew on the leaf surfaces Plants appear water-stressed and become stunted |
| Frangipani Caterpillar | Feed (cut, bite and swallow) on leaves and flowers of plumeria species Each caterpillar can eat 3 large leaves/day | Plumeria trees easily get defoliated in a matter of days |
| Nematodes | Attack the roots, leaves, and flowers by piercing them using its stylet | Roots develop gall, lesions, branching, and tip injuries Above-ground parts are having problems such as yellowing, wilting, and loss of vigor |
| Blossom Midge | Maggots feed on the closed flower buds | Discoloration and deformation of flower buds Premature blossom drop |
| Thrips | Puncture the plant tissues and suck their contents | Silvering of leaf surfaces Discolored leaf and flower surfaces. Brown spots on leaves. |
| Whiteflies | Pierce their needlelike mouthparts on the plant’s phloem Sucks the sap out of the plant tissues | Yellowing and death of leaves Plants become dry and fall off |
| Mites | Sucking the cell contents of the leaves | Leaves turn yellowish or reddish Damaged leaves may drop off |
Fungal Diseases
Another reason why plumeria leaves turn yellow is because of fungal diseases. One of which is the plumeria rust which is caused by the pathogen known as Coleosporium plumeriae Pat. The presence of this fungus creates a bright yellow or yellow-orange appearance on the upper side of the leaf surfaces.
The infection also leaves lesions and a sunken appearance. Later, the leaves deform, curl, and drop off from the plant.
Solutions:
- Remove infected leaves or plants and destroy them.
Fungal rust will easily spread from one site of infection to other plant parts. To prevent the spread, better remove the leaves that are already infected.
- Isolate the diseased plant.
To avoid infecting the nearby plants, you need to move a diseased plumeria to a secluded place. Isolate the plumeria in a location that is dry, well-lit, and less humid.
- Apply fungicides.
Find a suitable fungicide designed to kill the specific pathogen causing plumeria rust. Carefully follow the instructions in the label.
Nutrient Deficiency
The common sign you’ll observe with nutrient deficiency is the yellowing of the leaves. There are various types and degrees of yellowing depending on what type of essential nutrient is lacking.
The lack of iron, manganese, zinc, and nitrogen often leads to chlorosis or the lack of green pigment in the leaves.
Solutions:
- Conduct soil or tissue analysis.
The accurate way to know which nutrient is deficient is by subjecting the soil or the plant tissue to analysis. You can submit samples to the laboratory. However, you will incur costs in the process.
- Adjust the pH of the soil.
The pH of the soil affects the availability of nutrients and the population of beneficial bacteria.
Different plants have varying preferences for soil pH. Plumeria plants require a slightly acidic medium of around 6.4 to 6.8.
Test the pH of the soil first using a pH meter. Adjust it accordingly. You may apply aluminum sulfate or sulfur to the soil to alter the pH.
Excessive Feeding
Overapplication of fertilizer is also detrimental to the health of any plant. Surely they need all the essential nutrients to live but when they’re given in excess, the benefits are forfeited. Excessive feeding can lead to burning of the plant tissues.
Fertilizing plumeria should be done only during its growing stage. Use a high-phosphorus fertilizer to encourage flowering.
Excessive feeding happens when there’s enough supply of nutrients available in the soil and yet you continue to apply fertilizers.
Solutions:
- Leach off excessive fertilizer with water.
If you happen to overuse fertilizer on your plumeria, you may get rid of them by flushing them out with water. Pour the soil with enough volume of water successively. Let it flow and drain out of the pot.
- Skip the next fertilization schedule.
If the soil is not depleted, you may leave it be and stop fertilizing. Wait until the plant fully recovers. Generally, there’s no need to add fertilizers if the plant looks healthy.
- Replace the soil with a new one.
Too much fertilizer application also lead to the accumulation of salts in the soil. There are times when leaching won’t be enough to regain the quality of the potting mix. In that case, there’s a need to replace the medium with a fresh one.
Old and Depleted Soil
Healthy soil leads to healthy plants. But there can be a time when the soil health declines. In potted plants, this is very common.
When soil gets depleted, the nutrient level decreases. The population of good microorganisms also declines. Drainage is affected and toxins may accumulate.
All these things could adversely affect the health of the plumeria planted in that soil.
Solutions:
- Repot the plumeria.
One of the reasons why we do repot time and time again is to replace the potting soil of our plants. That way, the plant will continue to live healthily. You can do this every year or depend on the growth of your plant.
- Use the right combination of potting mix.
Different plants require varying mixes of potting medium. For plumeria, you should combine one part of perlite and one part of potting soil. Then, add one part of compost and one part of coarse sand.
Freezing Cold Temperature
Plumeria is sensitive to cold temperatures. It will not tolerate the freezing during winter. A temperature below 40oF (4oC) is destructive to the plant, leaving damage on the tissues, thus, the yellowing of the leaves.
Other than the temperature, cold drafts can also lead to the same damage. If your plumeria is being hit by an air conditioner, then, it must be the reason why its leaves are turning yellow.
Solutions:
- Bring the plant indoors when the temperature drops.
The temperature during the night is usually lower than in the morning. If your plumeria is located outside your home, care to bring it indoors during the night.
- Insulate the plant when the temperature is freezing.
Prepare for the winter season by covering your plumeria with cotton sheets. Choose a warm insulator to protect your plant.
- Relocate the plumeria to a warmer place.
Avoid exposure to cold drafts. Find a location inside your homes where there’s enough warmth. Preferably, choose a place with ample light sources.
Humidity
Being a tropical plant, plumeria loves high humidity. It needs a high level of moisture in the air to keep thriving. Such humidity will help the plant retain more moisture for itself.
With low humidity, the leaves will transpire at a faster rate. There’ll be rapid moisture loss. The leaves may die, turn yellow, and shed.
Solutions:
- Mist around your plumeria.
Spray water around your plant every morning. Do this when the environment feels really dry.
- Group your plumeria with other plants.
This way, each plant will benefit from the moisture released by the other. The water vapor is trapped within the surroundings.
- Invest on A Humidifier
Using humidifiers to combat dry weather is a very effective and easy way. It can continuously keep the humidity level up and your plumeria will not suffer from the low humidity effect.
Low Light
The lack of exposure to ample light may contribute to the yellowing of plumeria leaves. It creates a stressful environment for your plant. The lack of light will reduce its photosynthetic ability.
Due to a lack of food, the plant becomes less vigorous. Your plumeria becomes leggy and the leaves are either pale or yellow. They may also drop later in time.
Solutions:
- Expose your plumeria to full sunlight.
The current light condition is clearly not suitable for your plumeria. Bring it outside to receive enough sunlight. Just make sure to bring it in when the intensity gets too intense so it won’t be scorched.
- Provide extra sources of light.
There are times when natural sunlight is deficient. To augment the lacking light, you may provide additional sources. Install grow lights inside your home and place your plumeria near there.
Transplant Shock
If you’ve just transferred your plumeria from one container to another, don’t be surprised if the leaves start turning yellow. This is the result of transplant shock. Your plant has undergone a stressful procedure.
The yellowing might be a result of rapid moisture loss. Since the roots are still trying to establish themselves in the new environment, water transport may be a struggle.
Solutions:
- Place newly transplanted plumeria in a shaded place.
To conserve moisture, it would be best to provide shade in your plumeria. Avoid direct sun exposure to avoid wilting your plant.
- Water the soil thoroughly.
Keep the plant hydrated. Water the soil until it’s saturated. When the top portions start drying out, water again.
Natural Aging
Aged leaves will naturally turn yellow. It’s part of the normal process every plant undergoes. Yellowing due to aging is expressed in the older leaves of your plumeria plant.
There’s nothing that you can do to prevent senescence in your plant. In the same way, there’s nothing to worry about it.
Solutions:
- Remove the yellow leaves.
To keep the aesthetic appearance of your plumeria, better remove the aged leaves. Pluck them out with your fingers before they turn brown.
Overcrowded Pot
Plumeria doesn’t like getting pot-bound. When this happens, the roots get restricted and it affects their function. A too-small pot is not ideal for this type of plant because it will limit the nutrient and water uptake of your plumeria.
Solutions:
- Transfer to a bigger pot.
You may need to do this year by year. Choose a pot that is bigger in size but is proportionate to the plant.
- Prune the roots.
One thing that you can do to keep your plant in small size is to prune the roots. This will solve the problem of getting pot bound.
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How to Fix the Yellowing Plumeria Plant?
Knowing the possible reasons why your plumeria leaves are yellowing, you probably have the idea now how to bring in solutions to the problem. Just make sure that you’ve made the right diagnosis.
Here are some tips to fix your yellowing plumeria plant:
- Good lighting
Give not too much but not too little light and your plumeria will be happy. Know that bright light is a must but also consider the intensity. Protect your plant from harsh sunlight or add artificial sources if necessary.
- Right amount of water plus good drainage
To avoid the perils of overwatering, remember to water carefully. Keep the soil moist but not soggy. Give some time for the soil to dry out before watering again.
Above all, make sure that the pot has good working drainage excess water doesn’t get stuck.
- Good quality water
Rainwater is the best choice there is. If it’s not available, you may just filter the tap water or let it sit for 24 hours before using them on your plumeria.
- Just enough fertilizer
Your plumeria will need fertilizer only during its active season. After that, there’s no need to add fertilizer especially if the soil in itself is healthy.
Remember to dilute houseplant fertilizers so they won’t burn the roots. Make it a habit also to leach out the minerals from the pot after several months.
- Keep it humid
High humidity is a requirement for tropical plants like plumeria. It’s advisable that you place it in a location where there’s a high level of moisture or use a humidifier.
- Beware of the cold
Keep an eye on the temperature. Protect your plumeria from freezing.
- Sterile potting soil
When it comes to fungal diseases, prevention is better than cure. Always use sterilized soil on your potting mix. Pathogens can thrive in the soil and infect their host so better kill them ahead of time.
- Watch out for pests
Even if the plant looks healthy, don’t forget to check for any presence of pests from time to time. Most of these organisms work very subtly and you would never know they exist until their population has grown.
Caring for plumeria requires no special skill. It’s almost the same thing when you care for other tropical plants.
The yellowing of leaves is a common thing we observe from any plant every day. The reasons why this yellowing happens are pretty similar to other plants. The good thing is that you have the solutions mentioned above at your disposal.
So, it’s time for you to carefully observe your plumeria and find out the real cause of its yellowing.