Rhododendron leaves turning brown is most certainly no plant owners wish to see on their beautiful plants. But the reasons for this happening can be many. Following the right solutions is necessary to stop the browning from spreading to the rest of the plant.Rhododendron Leaves Turning Brown

While the damage is irreversible, this article will help you save your plant with the right diagnosis and solutions.

What Causes Rhododendron Leaves To Turn Brown?

The causes for rhododendron leaves to turn brown are excessive heat, cold and strong winds, or when it experiences late frost, or the scarcity of moisture surrounding it. It can also be due to transplantation shock, and also due to pests and diseases.

Even experienced growers have difficulty determining the cause of brown leaves on rhododendrons, so make sure that it is getting a solution to the browning as soon as the first leaf spot is seen. In short, if you try to catch the right cause, you will be very detailed on the recovery and the proper solution before it spreads entirely.

– Excessive Heat

The leaves will scorch and the slow transformation of brown rhododendron if the rhododendron plant is exposed to excessive heat throughout the summer. This problem is simply because you can shield the plant from direct sunlight, and it can become a sunburn, in the long run.

– Cold, Strong Winds

This can be a big challenge in the winter, especially if you are in an apartment or have your Rhododendron on a balcony. Cold winds tend to dry up the powdery mildew in the leaves.

The leaves store moisture because the plant cannot acquire enough moisture from the roots owing to the cold. However, some of the leaves will begin to turn brown. The same is true when you see the rhododendron leaves turning yellow.Causes of Rhododendron Leaves Turning Brown

– Late Frosts

The days are toasty, and your rhododendron plant is growing well, but some late frosts cause temperature fluctuations. The tension caused by such a rapid rise and fall in temperature will cause the rhododendron leaves curling and then turn brown.

This is why you see the yellow leaves and brown spots or browning of rhododendron leaves in winter. You don’t need to be concerned if this is only temporary because the leaves will recover and become healthy again.

– A Scarcity of Moisture

A lack of hydration is the most prevalent issue with rhododendrons and other garden plants. This could occur when the soil texture is poor and allows water to drain. Or the temperature is excessively hot, which causes the moisture to evaporate. Or you need to adequately water the soil, especially if growing in a container.

Because there is a water shortage, the roots cannot supply nutrients and moisture to the plant. As a consequence, you will start to see brown rhododendron leaves wilt.

– Shock After Transplantation

If you purchased a rhododendron seedling from a nursery or garden center, be cautious while transplanting it to your yard. If the plant is stressed due to the transplant, it will develop slowly, and the leaves may turn brown. It is recommended to harden the plant before transplanting it into the garden, and this implies you’ll need to ensure the seedling gets adjusted to being outside, as the leaves turn brown.

– Pests

Pests are common in all gardens; they might visit yours soon, if they haven’t already. If there are a few pests, they are harmless and can be ignored. However, if your garden is infested, your plants will suffer.

Mites, Gall Midge flies, vine weevil, aphids, and lace bugs are common pests of the rhododendron plant. Some of these pests, such as aphids, will suck the sap from the leaves, depriving them of nourishment.

As a consequence, the leaves will start to turn brown. Other pests, such as vine weevil, will eat away at the stems, depriving the leaves of nourishment and leaving them brown.

– Diseases

Diseases, like pests, can attack plants in your garden, including rhododendrons. The most common issue you may experience is root and crown rot. This fungal problem comes from either overwatering the plant or the soil becoming compacted due to people or animals walking over it. The excess water drowns the plant’s shallow roots and crown, causing them to decay.

The leaves will turn brown because the roots cannot deliver nutrients to the plant. They will droop and maybe fall off. For this, you can dig a small cavity in the soil to determine if the roots and crown are dark and moist in texture, indicating they are plagued by root rot.

What Are Solutions To Avoid Brown Rhododendron Leaves?

The solutions to avoid brown rhododendron leaves are to start planting them at the right depth, and provide adequate drainage, and remove the insects and pests from the surrounding. You must also sterilize the gardening gear, water and fertilize them properly, and fix the pH.

– Planting at the Correct Depth

Brown leaves can be reduced by planting your plants at the right depth, and it can assist the roots in getting adequate oxygen and keep them from decaying if your root ball is kept at least one inch above the soil.

– Providing Adequate Drainage

Ensure the pot contains drainage holes when repotting or planting your plants. The roots below will rot, and the leaves will get brown if sufficient drainage holes are not provided. The majority of plant containers already have drainage holes. If you still need one with drainage holes, construct them with a simple electric drill.

– Remove the Insects and Pests

There are numerous methods for preventing pests and insects from attacking your plant. Neem oil drops can be used to get rid of mealybugs and spider mites. Using a cotton bud with alcohol might also help eliminate certain insects and pests. However, spraying your plant with high-pressure soapy water can kill bugs or insects.

It is best to try to use organic approaches to eliminate pests on your plant. The greatest remedy is encouraging beneficial insects in your garden, such as lady beetles, wasps, and lacewings, and these pests are attacked and eliminated. Another way is to use a natural pesticide such as neem oil or insecticidal soap. Spray the mixture on the plant’s leaves to eliminate the pests.Remedies for Rhododendron Leaves Turning Brown

– Sterilizer the Gardening Gear

It is critical to disinfect all instruments used while pruning, propagating, or repotting your plant. Rubbing alcohol can be used to sterilize equipment.

Boiling water can also be utilized to sterilize metal and rubber equipment. Bring some water to a boil. When you notice bubbles developing, drop your equipment into the water and let it stay like that there for 30 minutes, and this way, you can use them in the right way avoiding disease.

– Watering Should Be Done Properly

Overwatering and under watering can be avoided by following one easy rule: check if at least one inch of soil has dried up. Once one inch of soil is dry, it is time to water your plant.

During the scorching summer season, keep an eye out for the soil’s moisture level because it dries out considerably faster. Water your rhododendron plant less frequently in the winter because it requires less water.

It is best that you go ahead and start checking the soil moisture near the rhododendron plant every day. Place your finger one to two inches into the dirt and feel for moistness on the tip of your finger. If it does not feel wet, you need to water it.

If you’re busy or traveling and can’t keep an eye on the soil, invest in a soaker hose or drip irrigation system with a timer. It would help to give the plant around an inch of water per week. When the temperature rises too high in the summer, you may need to increase the amount of watering.

Rhododendrons are shallow-rooted plants that require twice-weekly watering throughout their initial growing season. However, after the plants are established, you should only need to water them during dry periods, which should be two to three weeks without rain.

– Provide Adequate Lighting

Keep your plants in indirect sunlight, next to the window, and protected with transparent curtains. Never expose it to full sunlight, which can cause the leaves to burn. The afternoon sun is the most destructive to the rhododendron, whereas filtered or morning light is the ideal illumination.Adequate Lighting for Rhododendron

You can leave the seedling outside for two to three hours for the first several days. For this, you should keep it away from direct sunshine and strong winds. You can then gradually increase the time the seedling spends outside each day. You can transplant the seedling after a week.

The best remedy to this issue is to use a wind barrier to shield your plant from the wind. You can grow the plant in a place that is safe from strong winds, like near a tree or a wall.

You can use some screens to give shade to the plant, so when you’re growing in a container, relocate it to a shaded location. If you’re starting with these plants, remember that it’s best to plant them in partial shade, such as behind a tree or a wall.

– Adding Proper Fertilizer

Rhododendron plants require fertilizer only during their growing seasons, from spring to summer. During winter, you should stop giving your plant food and put covers on it. If the problem keeps happening for a few days, you can use a row cover at night to keep the plant safe.

Remove the row cover in the early hours, so the plant gets enough sunlight and aeration and avoid fertilizing so that it doesn’t build up salt in the soil.

During the growing season, only fertilize the plant once each month. Use a diluted fertilizer or a slow-release fertilizer to feed your rhododendron plant. Avoid spraying fertilizer on the plant’s leaves since salt production is the main cause of dark leaves.

– Fix the pH

Organic matter can help lower soil acidity only if it has become overly acidic. If the soil has become alkaline, sulfur can be used to lower the pH. You can make it happy by modifying the soils with peat moss, compost, and other soil minerals that add the acidity.

Rhododendrons also want soil that is rich in organic materials. This will keep the plants moist and prevent them from drying out; for instance, dry winters and late fall can especially damage rhododendrons.Solving Brown Rhododendron Leaves


Rhododendron is tricky to maintain and is not a recommended first-time plant for beginners. It can cause problems like brown leaves if correct care is not provided. Therefore:

  • Take care of the environment where the rhododendron grows. This includes the watering, soil type, and sunlight requirements.
  • Make sure you apply fertilizer to the plant only in the seasons where it grows. Otherwise, it will be a waste.
  • If you are thinking, should you remove brown leaves from rhododendron, you must know that it is necessary.
  • Any tool or utensil you use to prune, propagate or cut your plant needs to be cleaned and disinfected.

Growing a rhododendron may be tricky, but the right care can be very rewarding, so good luck!

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