Plumeria trees, which also go by the name frangipani, are wonderful tropical trees that produce gorgeous, fragrant flowers. Native to parts of Central and South America as well as the Caribbean, they grow beautifully in zones 10-12. For cooler climates, the shorter cultivars make wonderful container trees. While they are tolerant and low-maintenance in general, there are a handful of problems that you could face when caring for plumeria plants. 

For the most part, plumerias are drought-tolerant, problem-free, and thrive in full sunlight. They tolerate poor soil conditions and aren’t particularly attractive to pests. Plus, they are incredibly easy to propagate from cuttings and reliable, robust bloomers. These tropical species are comfortable with humidity, and their open branching form keeps air circulation through the substantial foliage.

If you have a plumeria, you are already familiar with its positive attributes. So it may come as a surprise when something goes wrong with your tree. If you’ve found your way here because your plumeria is looking ill, read on. We’ll see if we can identify the problem, and I’ll tell you how you can mitigate the damage and get back on track to a healthy tree.

Fungal Diseases

Plumerias are generally happy in and tolerant of high-humidity environments. However, because they primarily grow in humid climates, they are susceptible to some common fungal issues and diseases. Lack of ventilation and air circulation are usually the cause of these diseases, but poor watering habits can also be a culprit. 

Root Rot

This disease is common among these plants.

Root rot is a common fungal problem for plumeria trees. It’s also one of the more serious issues you can encounter. If you don’t catch it early, it can be deadly. The most common pathogens to cause root rot are Phytophthora and Pythium. 

Symptoms of root rot include wilting or drooping leaves, often accompanied by moist soil. If the tree looks dehydrated, but it has access to water, there is a good chance you have root rot. Other symptoms include leaves turning yellow and falling off, a soft, blackened base of the stem, and foul-smelling roots. 

Since you can’t see the roots without digging up your plumeria, it’s difficult to tell when the rot first begins. This creates a catch-22 because without seeing them, you won’t know until the root rot is affecting the rest of the tree. 

How to Fix It:

If you notice these signs and suspect root rot in potted plants, remove the plant from the pot immediately. Rinse the dirt from your roots and examine for signs of healthy root tissue. Healthy roots will be firm and light colored, while rotten roots will be dark and mushy. 

Use clean scissors to remove all the rotted root tissue, and then allow the roots to dry completely. Replant in fresh, clean, well-draining soil and water sparingly. When new growth appears, you will know that your solution was effective. 

For plumeria trees planted in the ground, it’s more complicated. You can go through this process if the tree is small enough; however, for larger trees, it’s challenging to dig them up and relocate them. If you notice signs of root rot, stop watering immediately. 

Plumerias rarely need supplemental water. Unless you experience a prolonged drought, you shouldn’t have to water at all once it’s established. They act like succulents, holding water in their thick stems. 

Ensure that when you plant your tree, it’s in a location with well-drained soil. This is the most effective way to prevent root rot. If you’re concerned that your tree is past the point of saving, it’s easy to propagate from a healthy branch. 

Cleanly remove a healthy branch and simply plant it in soil, keeping the soil lightly moist until it roots. Be careful not to overwater, as you’ll end up back where you started. While your new tree will be smaller, it’s a good way to preserve some part of an otherwise dying plant. 

Plumeria Rust

This problem typically appears on the plumeria leaf’s underside.

Plumeria rust is a common fungal disease problem that is easy to recognize by its bright orange or rust-colored spots on the underside of leaves. You may notice it first as yellow spots on the top surface of the leaves. This disease typically affects the P. rubra species and its hybrids.

The fungal pathogen that causes rust on plumerias is called Coleosporium plumeriae. Although it’s unlikely to kill the plant, it can significantly weaken it if you let it go long enough. The primary causes of this fungal infection are high humidity, inadequate air circulation due to overcrowding, and overhead watering.

How to Fix It:

As soon as you notice the spots, remove the damaged foliage as quickly as possible. This will prevent it from spreading further. Clean up any leaves on the ground as well, as they can also harbor the disease. 

Enhance air circulation by pruning your plumeria tree to open its canopy and the surrounding trees to improve ventilation. Then treat the remaining foliage with a copper-based fungicide or a sulfur fungicide. Neem oil is another effective treatment for rust, and it’s safer for the environment and wildlife. 

Black Tip

This disease stunts growth and makes parts die back.

Black tip is another fungal problem that some plumeria trees are susceptible to. Symptoms of this disease include blackened, shriveled tips with soft and mushy tissue at the ends. It will ultimately stop the branches from growing, and the tip may die back. 

This disease doesn’t happen as the result of one specific pathogen. It’s commonly the result of cold damage, which we will cover in a minute. Cold damage makes the tissue more susceptible to fungus, so the black tip is usually a result of a secondary infection.

Pests

Pests are less common problems for plumerias, but not unheard of. If you’re growing your tree indoors, there is a higher risk of pest infestation. Warm, humid conditions are also a risk factor, so you’re more likely to see this issue in the summer rainy season than other times of year. 

Aphids

They target young and new plant parts.

Aphids can be a problem for plumeria trees and typically appear in time for the growing season. They prefer new, tender growth and flower buds, which are all easier for them to puncture and feed from. This weakens the tree and makes it more vulnerable to diseases, and can also look unsightly. 

Aphids are easy to identify. They are small, soft-bodied insects that usually travel in large groups. You’ll often find them on newer stems and leaves, as well as flower buds. They may cause leaves to pucker and curl, and buds to drop early. 

These pests, along with several others, also leave behind a second problem. Their sticky, sweet excrement is a breeding ground for black sooty mold, which inhibits photosynthesis. This further weakens the already vulnerable tree. They can also carry viral diseases, though plumerias are not usually affected. 

How to Fix It:

If the infestation is minor, and you catch it early, you may be able to simply wipe them off and pinch off tips where they’re concentrated. You can also knock them off with a strong stream from the hose. 

Attracting beneficial insects to the yard is excellent prevention, as many of their larvae are voracious predators. Ladybugs and lacewings are fantastic for controlling pest populations of most kinds. 

If all else fails, neem oil is a safe insecticide, as long as you spray it in the early morning or at dusk when pollinators are no longer present. If it dries quickly, it’s safe for bees and butterflies. 

Whiteflies

This is a common pest that affects these plants.

Whiteflies are common garden pests that can cause significant stress to your plumeria. Like aphids, they feed on sap, sucking out nutrients and moisture. They leave behind their excrement, called honeydew, which causes sooty mold and further weakens the plant. 

These are tiny insects, but you can usually determine their presence by disturbing the foliage. They will fly around when you disturb their hiding places. They’re easily identifiable as small, white flying insects. 

How to Fix It:

In my experience, yellow sticky traps are often the most effective way to control whiteflies. You hang them near the areas where they tend to congregate, and they are attracted to the color. They fly to the traps and get stuck. These attract pollinators, though.

If this isn’t effective, neem oil and horticultural oils are also effective treatments. I advise against using these while the tree is in bloom, as they can be harmful to pollinators and other beneficial insects. 

Spider Mites

This pest loves dry climates.

Spider mites are more of a problem for indoor plumeria plants, as they thrive in drier environments. They cause similar damage to aphids and whiteflies, sucking the life out of your tree.

These mites are so tiny that you may not be able to see them. If you see your plant suffering and can’t identify any other cause, look under the leaves and in the petioles for their fine webbing. This is usually the easiest indicator to identify them by. 

How to Fix It:

Spider mites are a major headache because they can be challenging to eliminate. If your plant is indoors, they don’t have any natural predators to help out, so you’ll need to treat it. Neem oil and other horticultural oils usually do the trick, but you may need to treat the area more than once. 

Isolating infected houseplants is essential, as this controls the spread of pests from one plant to others. Make sure to isolate your plant if you suspect or identify pests.

Mealybugs

They appear on plants placed indoors and outdoors.

Indoors or out, if your plumeria is in a warm, humid environment, mealybugs are a pest that can appear. They’re easy to identify, so they’re easy to diagnose. 

Mealybugs are small, soft-bodied pests that appear to have a cottony coating on their bodies. It’s actually a waxy coating, and they are easier to eradicate if you break down that coating. You’ll find them in clusters around leaf axils, along stems, and sometimes on flower buds. 

How to Fix It: 

For light infestations, you can use an alcohol-soaked cotton ball to wipe the bugs away. Rinse afterward to remove the residual alcohol and any leftover bugs. Neem oil is also effective, but make sure you repeat it after five to seven days to break the reproductive cycle. 

Environmental Stress

Plumerias are tropical trees that thrive in warm, humid weather and require ample sunlight. There are environmental conditions that can negatively impact their health, particularly if you’re growing them in a climate that is unlike the one for which they’re suited. 

Nutrient Deficiency

Too much nitrogen can affect how the flowers bloom.

Nutrient deficiency can cause several problems for your plumeria. These trees need a hefty supply of phosphorus if you want them to bloom well. An overabundance of nitrogen can also cause blooming issues. If your tree isn’t flowering, it may be due to a nutrient deficiency.

How to Fix It:

Test your soil to determine its nutrient availability. Too much nitrogen will lead to excessive lush, green growth, but few flowers, as the plant directs its energy to the leaves. A shortage of phosphorus will also result in fewer blooms or weaker flowers that can even drop off before they open. 

During the growing season, fertilize about once a month with a phosphorus-rich fertilizer. A formula of 10-30-10 is ideal, but any bloom boosting formula should do the trick!

Cold Damage

The plant does not do well in cold weather.

Plumerias don’t tolerate cold weather and are not frost-tolerant. Temperatures below 40°F (4°C) may cause issues, and temperatures below freezing will likely result in tip damage. Ultimately, cold damage will cause fungal issues and may even stop the tree from leafing out in the spring. 

How to Fix It:

Offer your plumeria some protection in cold weather. Bring potted plants indoors, and use frost cloths or blankets to protect those outdoor plants. Water ahead of colder weather, but not during cold weather. 

Wait until spring to take action on cold damage that is already present. Hold off on pruning, as the damage may not be as severe as it looks. You’ll know what is truly dead because it won’t grow leaves. 

You can also scratch the bark off to see if the limb is still alive. If it’s green underneath, it’s still alive. If it’s brown, prune it back to live tissue. Prune black, mushy tips back to healthy, firm wood. Make sure to always use a clean, sharp tool. Clean cuts heal fastest. 

Leaf Scorch

This plant needs full sun, but too much sunlight is also harmful.

Leaf scorch is another environmental issue that can affect plumerias. While they do prefer full sun exposure, they require a specific combination of environmental conditions for optimal health. They also require humidity, along with sunlight. 

If you live in a dry climate, even if it’s warm enough for a plumeria, it may be challenging to grow them successfully outdoors. If the tree is suffering from dehydration due to a lack of humidity, strong winds, or insufficient rainfall, the leaves are more susceptible to sunburn. That’s essentially when leaf scorch is. 

How to Fix It:

If you’re experiencing drought, water deeply but infrequently. Don’t water a bit every day. Instead, give a more substantial amount of water once or twice a week during periods without rain. Mulch helps to hold moisture in the soil, so layer on some mulch in the spring to insulate the roots from dry weather. 

Leaf scorch may look serious, but it usually isn’t. Most trees will bounce back from it, and new foliage will grow to replace the damaged leaves.

Lack of Light

The plant will suffer if it does not get enough sunlight.

Finally, a lack of adequate sunlight can negatively impact your plumeria. If your leaves are looking pale and listless, or the tree isn’t producing flowers, a lack of light may be the issue. 

How to Fix It: 

Always choose a location for your plumeria that receives at least six hours of sun daily. If you’ve planted one in the ground in a spot that’s too shaded, it’s best to either move it or prune the plant that’s blocking the light. If you’re dealing with a potted plant, it’s easiest to simply relocate it.