Home > mandevilla leaves turning brown

Mandevilla Leaves Turning Brown: Causes and Solutions


Mandevilla is a beautiful flowering plant. It is popular in gardens and indoor spaces. Dipladenia leaves turning brown is indicative of underlying problems. We will discuss the causes behind mandevilla plant leaves turning brown and how to prevent it.

Understanding Dipladenia Plants

Description of Dipladenia Plants: Mandevilla is also known as dipladenia or rocktrumpet. It belongs to the Apocynaceae family. Dipladenia plants leaves 4-6 inches long and 2-3 inches wide. The dipladenia leaves are smooth and have a slightly waxy texture. This gives them a shiny appearance. Mandevilla has woody stems and can reach 15 feet in height.

Popular Species and Varieties: The most popular species of dipladenia is Dipladenia sanderi. It has bright red or pink trumpet-shaped flowers. Other popular species include D. boliviensis with orange-red flowers and D. splendens with star-shaped white flowers.

There are also many hybrid varieties of dipladenia. For example, the Rio series. They offer different colors. For example, pink, red and white. The Mini series is another popular choice. They offer smaller-sized plants with a compact growth habit.

Why Are Mandevilla Leaves Turning Brown and Falling Off?

Environmental Factors

Insufficient Sunlight: Leaves are a vital organ for plants. They conduct photosynthesis. Mandevillas require a significant amount of sunlight to thrive. The leaves may turn brown and drop if your plant is not getting enough light.

Extreme Temperatures: Mandevillas prefer warm and consistent temperatures. Mandevilla plant leaves turn brown if the temperature drops below 55°F or rises above 90°F.

Inadequate Humidity Levels: Mandevillas are tropical plants that thrive in high humidity. If the air is too dry, the leaves may turn brown and crispy.

Overwatering or Underwatering: These can both lead to browning leaves. Overwatering can cause root rot. It affects the plant's ability to absorb nutrients and water. This results in brown leaves on mandevilla. Underwatering can cause the leaves to dry out and turn brown.

Pests and Diseases

Common Pests: Aphids are small, pear-shaped insects. They love to feed on the sap of young leaves. This can cause stunted growth and distortion in plants. If you notice curled or yellowing leaves with sticky residue, it may be a sign of aphid infestation.

Spider Mites thrive in hot and dry conditions. They can cause yellowing, stippling, and webbing on the undersides of leaves. Whiteflies are tiny white insects. They also feed on plant juices. This can lead to yellowing or browning of leaves, as well as stunted growth.

Common Fungal and Bacterial Diseases: They can cause brown spots on dipladenia leaves. Powdery Mildew appears as a powdery white substance on leaves and can cause them to turn brown and wither. Botrytis thrives in cool, moist conditions and causes brown spots on leaves, stems, and flowers. Bacterial Leaf Spot causes brown spots with yellow halos on leaves.

Nutritional Issues

Lack of Essential Nutrients: Mandevilla leaves turning brown may lack essential nutrients. Nitrogen is responsible for promoting healthy leaf growth and chlorophyll production. Phosphorus aids in root development and flower formation. Potassium helps with overall plant health, including disease resistance and water regulation.

Imbalanced Soil pH: Another potential cause of browning leaves in mandevilla plants is an imbalanced soil pH. The ideal pH is between 5.5 and 6.5. It falls into the slightly acidic category. The pH level too high or too low can affect the plant to absorb essential nutrients. Some other factors can also affect soil pH. For example, nearby plants or building materials.

Improper Pruning

Incorrect Pruning Lead to Brown Leaves: Pruning is an essential task in maintaining the health and appearance of mandevilla plants. It involves removing dead, damaged, or overgrown branches. This encourages new growth and maintains a desirable shape. However, if done incorrectly, pruning can cause more harm than good.

When pruning, make clean cuts at a 45-degree angle just above a node or bud. If the cut is too close to the stem, it can leave behind a wound that takes longer to heal. It is more susceptible to diseases and pests.

Mandevilla plants need their leaves to absorb sunlight and nutrients for photosynthesis. If too many leaves are removed, the plant may not have enough energy to support new growth. This leads to brown leaves on mandevilla.

You should prune mandevilla plants after they finish blooming in late fall or early winter. Pruning at any other time can disturb the plant's growth cycle and cause stress, which can manifest as browning leaves.

mandevilla in pots

Identifying the Problem

Visual Inspection: The first step in identifying the cause of browning leaves is to visually inspect your plant. Browning leaves usually have a dry, crispy appearance and may also have yellow or black spots. In some cases, the entire leaf may turn brown and fall off.

Some varieties of mandevilla have naturally brown or dark-colored leaves. This is not a sign of any underlying issue. Compare it with the rest of your plant's foliage to determine if the browning is abnormal. A stark contrast in color or texture may be an underlying problem.

Check for Pests: Pest infestation is a common cause of browning leaves in mandevilla plants. You should closely examine the browning leaves, especially on the undersides. You may need to use a magnifying glass to spot tiny insects or their eggs.

Soil and Nutrient Testing: Another factor that can contribute to browning of mandevilla leaves is soil issues. This includes an incorrect pH level or a deficiency in essential nutrients. You can send a soil sample to the laboratory. You should observe any yellowing or discoloration of leaves. Comparing it with a chart shows the signs of specific nutrient deficiencies.

Assessing Environmental Conditions: Evaluate the environmental conditions in which your mandevilla plant is growing. Light, temperature and humidity are all important in plant health. They can contribute to mandevilla leaves turning brown and falling off if not properly maintained.

Dipladenia plants thrive in bright, indirect sunlight. Too much direct sunlight can cause leaf burn. Too little light can result in slow growth and weak foliage.

Mandevillas prefer warm temperatures between 65-85 degrees Fahrenheit. If the temperature drops below 50 degrees, it can cause leaf browning and even kill your plant. Humidity is also important for mandevilla plants. They prefer a humid environment with levels between 40-70%.

Remedies and Solutions

Addressing Environmental Factors

Providing Proper Sunlight and Temperature Conditions: Placing mandevilla plants in an area with 6-8 hours of sunlight. However, avoid placing it in direct sunlight. This can cause the leaves to turn brown due to sunburn. If you are growing mandevilla indoors, place it near a window with ample indirect sunlight.

Any extreme fluctuations or prolonged exposure to cold temperatures can cause the leaves to turn brown. If you live in a colder climate, consider bringing your mandevilla indoors during winter or providing additional heat sources, such as a heat lamp.

Maintaining Optimal Humidity: Mandevilla plants thrive in humid conditions. The leaves can turn brown and wither if the air is too dry. You can mist your plant daily to maintain optimal humidity levels. Alternatively, you can use a humidifier to maintain consistent humidity levels.

Watering Guidelines: Proper watering is crucial for the health of your mandevilla plant. Over or under-watering can both lead to brown leaves. Inserte your finger an inch deep into the soil to check the soil moisture regularly. If the top inch of soil is dry, it's time to water.

Water thoroughly saturates the soil until water drains out from the bottom of the pot. Ensure the roots receive enough moisture. Allow excess water to drain out completely. Because stagnant water can lead to root rot and brown leaves.

Dealing with Pests and Diseases

Natural Remedies for Common Pests: Neem oil is a natural insecticide. It can be effective against common pests. For example, aphids, mites, and whiteflies. Mix one tablespoon of neem oil with one gallon of water. Spray it on the affected areas of your plant.

A mixture of mild liquid soap and water can help to control pests. For example, spider mites and mealybugs. Spray the solution onto the leaves, stems, and flowers of your mandevilla plants, making sure to cover all surfaces.

Encouraging beneficial insects to your garden can help control pest populations naturally. For example, ladybugs, lacewings, and praying mantises. Planting flowers that attract these insects can attract them to your garden. For example, marigolds or dill.

If you notice larger pests on your plants, manually removing them is an effective method. For example, caterpillars or slugs. Simply pick them off your plant and dispose of them.

Fungal and Bacterial Disease Management: Carefully prune off any affected leaves and branches if you notice browning or wilting. If the disease is more widespread, you should use a fungicide spray to treat it. Look for products specifically designed for controlling fungal and bacterial diseases.

Overwatering can contribute to the development of fungal diseases. So only water your mandevilla when the top inch of soil is dry. Also, avoid getting water on the leaves as this can create a damp environment for disease to thrive.

Nutritional Solutions

Choosing the Right Fertilizer: Look for a balanced, slow-release fertilizer specifically designed for flowering plants. Fertilize your mandevilla every 2-3 weeks during the growing season.

Application Methods: When applying fertilizer, make sure to follow the instructions on the package carefully. Too much fertilizer can burn the roots and cause damage.

Adjusting Soil pH: Mandevilla plants prefer a slightly acidic soil. If your soil is too alkaline, you add elemental sulfur or organic matter. For example, peat moss or compost.

Pruning and Care

Correct Pruning Techniques: When pruning, make sure to use clean, sharp tools. Cut just above a node or where the stem meets another branch. This will promote new growth and prevent damage to the plant.

Timing: The best time to prune your mandevilla is in early spring before new growth begins. This will give the plant time to recover and produce new healthy leaves.

Maintaining a Healthy Plant Structure: Regularly inspect your mandevilla for any signs of disease or pests. Promptly treat them if necessary. Also, make sure to provide adequate support for the plant's vines as they grow. This prevents them from becoming too heavy and causing damage.


Why is my dipladenia leaves turning brown? Leaf browning is a common issue that many Dipladenia plant owners face. We have discussed the causes and solutions for mandevilla leaves turning brown. It is important to address this issue promptly in order to maintain healthy green foliage and vibrant plants.


Name:Vincent Lee





Processed in 0.005395 Second.