Hydrangea Leaves Turning Yellow (8 Causes And How to Fix It)


If you are a beginner gardener then you probably face a common problem of hydrangea leaves turning yellow. Sometimes you may try to change the maintenance requirements randomly. 

But you make it worse doing it that way. In such a situation, it is important to determine the cause as soon as possible and immediately begin treatment.

If your indoor hydrangea leaves turn yellow, you can easily restore the beautiful appearance of your hydrangeas. I will walk you through the step by step process. 

Let’s dive in.

Why are my hydrangeas leaves turning yellow? Hydrangeas leaves turn yellow due to care mistakes. The most common reasons for hydrangeas leaves turning yellow are the following:

  • Lack of light or excessive lighting
  • Waterlogging condition
  • Soil Dryness
  • Drafts, cold winds and temperature changes;
  • Soil depletion
  •  Low  soil acidity
  • Deficiency of nutrients and minerals especially after flowering;
  • Diseases
Hydrangea leaves turning yellow. Four leaves showing change of color

Yellowing Types of Hydrangea Leaves

Before going into the solutions to the problem. Let’s identify the types of problems. There are three types of hydrangea leaves yellowing:

  1. Leaves turn yellow completely and fall off
  2. Leaves turn yellow and the veins are green
  3. Only the edges of the leaves become yellow

Leaves Turn Yellow Completely and Fall Off

With this symptom, you should pay attention to several factors: 

  • waterlogged soil; 
  • low temperature and cold air; 
  • lack of minerals during the formation of buds and flowering.

Sometimes hydrangea yellow leaves at bottom may be due to normal aging process. The leaves at the bottom will turn yellow with time and fall off.

Hydrangea Yellow Leaves Green Veins

Chlorosis is one of the reasons hydrangea changes leaf color, while the leaf vein remains green. Such disorder occurs due to iron deficiency. You can help your hydrangea leaves by adding chelated iron to the soil with water.

Only the Edges of the Leaf Become Yellow

Hydrangea leaf edges turned yellow, what should I do? Especially if not the whole sheet turned yellow, but only its edges. 

Be sure to feed the plant with nitrogenous fertilizers with iron content. Lack of these trace elements will lead to yellowing of the lower edge of the leaves.

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Causes and How to Fix Yellow Hydrangea Leaves

I already listed the reasons for hydrangeas leaves turning yellow. Now, Let’s jump into the detail of why the hydrangea leaves turn yellow and how to deal with it.

Lack of light or excessive lighting

Hydrangea is a light-loving species but does not tolerate direct sunlight. Incorrect placement of the plant pot can lead not only to the yellowing of the leaves but also to the complete drying of the plant.

When choosing a location, you must consider that it doesn’t get direct sunlight. 

Warning! 

UV radiation is the most dangerous between 12 and 15 hours of the time period.

The best place to land is in the area where sunlight hits in the afternoon and for no more than 6 hours.

Otherwise, the shrub can get a serious sunburn. Semi-transparent stains may appear on the leaves, and then they turn yellow and dry.

Important! 

Hydrangea also doesn’t like dark areas. It doesn’t feel good where it is darkened by tall plants with a lush crown or other bigger shrubs.

Water Logging Condition

Another reason why hydrangeas have yellow leaves is the wrong watering. Hydrangeas are water-loving plants, but will not grow in wetlands.

The root part begins to rot due to the constant dampness and over time the plant dies. In this case, you should stop watering or reduce the frequency.

You can easily protect the shrub from the water logging condition. Make a drainage layer of stones or broken bricks at the bottom of the pot before planting or while transplanting.

You have to water hydrangeas systematically. The frequency of watering depends directly on external factors. If the topsoil layer is dry, you should moisten it.

I have written a separate article on how to save over watered hydrangea. In this article, I have described step by step process to save your hydrangea.

Soil Dryness

If the ground underneath the plant is constantly dry, the leaves will eventually turn yellow and fall off.

In the initial stage, you will see yellowness appearing at the tips and edges of the leaf.  Then it begins to twist. So, what should you do to save your plant? Let’s find out.

You should not allow the soil substrate to dry out. Irrigate your plant with warm water twice a day. Use mulching to retain the soil moisture for a longer time.  

For your information! 

Shredded conifers, cones, wood chips can be used for mulch. 

Plant your outdoor garden hydrangeas away from the trees. Close proximity can damage the shrub.  As it will not have enough water for life, growth and will start to dry out.

Drafts, Cold Winds and Temperature Changes

Hydrangea feels good in an area where there is no strong wind, for example, next to a wall or fence. Because drafts have an adverse effect on the plant. Leaves begin to turn yellow and dry over time.

In combination with low temperatures, the effect is accelerated several times, the plant dies faster. 

The optimum temperature within the home for growing hydrangeas is +22°C (71.6°F).

If you raise this threshold, the plates will start to turn pale and turn yellow. This plant can not sustain sharp changes in the external environment. 

Just for the record! 

You should grow the outdoor species in the garden near the fence or against a wall.  This will protect them from wind and drafts.

Drafts in hydrangeas reduce immunity and lead to diseases. Keep this plant in cool rooms for the whole autumn-winter period.

In this period the optimum temperature is +8°C (46.4°F).  After hibernation, you can return the hydrangea to its previous place. 

Soil Depletion 

A common reason for hydrangeas leaves turning yellow is the lack of trace elements in the soil. Due to the lack of nutrients, the plant’s immune system undergoes serious attacks. 

You should regularly fertilize the potting soil with complex mineral fertilizers. Don’t forget to apply fertilizer at the time of planting. The soil should be suitable for acidity. The suitable range for hydrangeas is pH 5.5 and 6.5.

Make sure the soil is fertile. It should consist of two parts of the earth and humus, one part of peat and sand.

It would be great if you can add some decomposed manure. Before the arrival of spring fertilize the hydrangeas soil with urea fertilizer. 

Important! 

During the period of budding and flowering, you must feed your hydrangeas at least 3 times. 

The nutrients in pot soil deplete over time. That’s why you have to recharge it every year. You can do this by applying fertilizers to the soil. When the plant flowers or new leaves are born and it needs a lot of nutrients.

So if you do not supply nutrients, it may simply not flower next year. The fertilizer solution should contain potassium sulfide and superphosphate components.

Low Soil Acidity 

Another reason why hydrangea leaves turn yellow is the alkaline substrate. If the pH is not normal, the leaves turn yellow.

All hydrangeas feel great in acidic soil. Therefore, before planting, you should test to determine this parameter. Because leaves may turn yellow due to low acidity.

The shrub has healthy and strong shoots. As you already know that this plant grows well in the soil with a pH of 5.5–6.5. 

If your potting soil is not acidic, you can correct the pH of soil easily. To acidify the soil,  occasionally water it with a solution of acetic or citric acid (4-5 ml per 1L of water). You can use mulching to retain the soil moisture.

Deficiency of Nutrients And Minerals After Flowering

One of the reasons for the appearance of yellow leaves in hydrangeas is a deficiency of nutrients.

From early spring to mid-summer, it needs regular feeding. Before flowing in spring the plant needs more nutrients than normal time. 

Deficiency of nutrients, in particular nitrogen and iron, is threatening:

  • incomplete formation of inflorescences;
  • yellowing of the leaf tips;
  • drying out and falling of leafy greenery.

The solution to the problem is timely application of fertilizers.

Diseases of Hydrangea

Hydrangea leaf color changes due to 
 chlorosis.
  • Chlorosis: Your hydrangeas leaf colors may change due to chlorosis infection. The disease appears as follows: the leaf plate turns yellow with bright green veins. In order to help the plant get rid of this disease, you need to prepare a solution consisting of 30 ml of potassium nitrate and 10L of water. Then, water the shrub 1 time a week for 30 days.
  • Gray rot: If the leaves of the plant begin to blacken, curl, and crumble over time. Then your hydrangea has become infected with gray rot. To combat this fungal disease, you need to use a 1% solution of the Bordeaux mixture.

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Root System Damage 

The root system of hydrangea is quite weak. It can easily be damaged during planting and transplantation. Small wounds can lead to infection of the plant, drying out of its leaf system. 

Attention! 

Pruning root systems will result in stunted growth and various diseases of hydrangeas.

Therefore, you should treat the root with charcoal before transplanting. This will help the root to get rid of any kind of fungal or bacterial infection. 

Why Do Different Species of Hydrangeas Leaves Turn Yellow?

Each species of hydrangea requires certain care and special growing conditions. 

  • Panicled hydrangea: Gradual yellowing of leaves in panicled hydrangea may be due to improper care. This type of shrub feels good in a temperate climate. The flowering period lasts almost the entire summer period- from early June to early August.
  • Bigleaf hydrangea: Large-leaved hydrangea is suitable not only for gardening but also for the indoor garden. growing. Care,  watering rules, soil composition are almost the same as when growing geraniums. It begins to bloom in the spring and pleases you with its inflorescence almost until the summer. The leaves in this variety of hydrangeas turn yellow most often due to fungal infections. 
  • Tree hydrangea: This is a very simple type of hydrangea. It leaves turn yellow mainly due to care mistakes. 

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How to Apply Fertilizer When Hydrangea Leaves Turning Yellow

Nutrient deficiency is one of the main reasons for leaves turning yellow. So you have to supply proper nutrition to your hydrangea to save it from yellowing. 

In the spring season make a nitrogen-containing mixture to increase the green foliage.

In summer, choose a fertilizer that contains the major nutrient elements like nitrogen, phosphorus, and potassium for rich flowering.  

And finally, in the fall months, potassium-phosphorus composition to prepare hydrangeas for wintering.

If the plant suffers from iron deficiency, water your hydrangea with Chelated Iron Solution.

Besides yellowing, there are some other possible leaf problems

Leaves Turn Pale (lighter) 

Hydrangea leaves may turn pale due to infestation with powdery dew. If you do not remove the infected areas in time, the disease will spread quickly to the whole plant. In this case, you should consider applying a fungicide. 

Leaves Become Black

If the leaves have dry black spots, the plant is either watered with unsuitable water or is exposed to direct sunlight. You can bring the shrub back to normal by changing the conditions. 

Leaves Twisted

Hydrangea leaves are twisted because they have been affected by harmful parasites. In this case, carry out a thorough  inspection and emergency treatment with insecticides 

Here is a useful video on leaf turning yellow and how to prevent it.

How To Prevent Yellowing of Hydrangea Leaves

It is necessary to provide quality growing conditions to prevent the yellowing of your hydrangea plant. Here are some actionable tips to prevent the problem. 

  • Find a place for your hydrangea so that the delicate plant remains under diffused sunlight;
  • It is important to control the level of soil moisture to prevent drying out or excessive moisture;
  • Use settled water at room temperature for irrigation.
  • In the rainy season, add wood ash under each bush of garden hydrangea – this will help the roots adapt to adverse conditions;
  • Control the level of acidity and soil leaching;
  • At the stage of active budding and flowering maintain the health of the shrub with  mix fertilizers;
  • Spray with 1% Bordeaux solution once in a month. This will prevent fungal diseases and attacks of harmful insects. 
  • Systematically revive hydrangea by removing old and diseased stems.

Conclusion

Keeping your indoor plants beautiful and healthy is not at all difficult. The main thing is to properly and timely care for the plant, as well as not to neglect preventive measures. You have to take measures to avoid various diseases and infections.

So, what solution are you going to apply? Let me know by dropping a comment below. Besides, If you have any suggestions feel free to share.

Arifur Rahman

I'm the owner of gardenforindoor.com. After completing my bachelor of science in agriculture, I'm serving as a civil service officer at the Department of Agricultural Extension, Bangladesh. I started Garden For Indoor to make your indoor gardening journey easy and enjoyable.

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