Why do Hydrangea Leaves Turn Purple: Causes and Solutions

Hydrangeas are one of the most popular flowering plants that usually bloom in spring and summer seasons. These plants are known for their beautiful clusters of flowers that come in various shapes and colors. However, sometimes hydrangea leaves also turn purple or purple-red, which may indicate a problem.

Overview of Hydrangeas

Hydrangeas are deciduous shrubs that belong to the family Hydrangeaceae. They are native to Asia and America and have over 70 species. These plants need well-drained soil, plenty of water, and partial shade. Hydrangeas can grow up to 6 feet tall and 8 feet wide, depending on the variety.

Common Colors of Hydrangea Leaves

Hydrangea leaves come in different shades of green, from dark to light-green. However, when the plant is under stress, the leaves may turn yellow, brown, or purple. The color change may be caused by various factors like environmental conditions, nutrient deficiency or excess, or even a disease. In this article, we will discuss why hydrangea leaves turn purple, what causes it, and how to solve the problem.

Causes and Solutions for Hydrangea Leaves Turning Purple

There are several reasons why hydrangea leaves may turn purple or purple-red. Here are some common causes and solutions:

Soil pH Level

One of the most common reasons for hydrangea leaves turning purple is a change in soil pH level. In general, hydrangeas prefer acidic soil with a pH range of 5.2 to 6.0. If the soil pH level becomes too high (alkaline), the plant may struggle to absorb vital nutrients from the soil, leading to a deficiency, which can cause purple leaves.

Solution: To fix the problem, you can adjust the soil pH level by adding aluminum sulfate or sulfur to the soil to increase acidity. You can also use a pH tester kit to monitor the soil's pH level and make adjustments accordingly.

Fungal Infection

Another cause of hydrangea leaves turning purple is a fungal infection. The most common fungal infection that affects hydrangeas is Cercospora leaf spot. This disease causes purple spots on the leaves, which can eventually lead to defoliation.

Solution: To prevent fungal infections, make sure to water your hydrangeas early in the day so that the leaves dry off before nightfall. You can also use fungicides to control the disease if it has already infected the plant.

Sunlight Exposure and Temperature

Intense sunlight exposure and high temperature can cause hydrangea leaves to turn purple. When the plant is exposed to too much sunlight, it becomes dehydrated, leading to the breakdown of chlorophyll, which gives the leaves their green color.

Solution: To avoid sunburnt leaves, you should plant hydrangeas in partial shade or provide them with a shading cloth during hot summer months. Make sure to water the plant regularly to prevent dehydration.

Nutrient Deficiencies

Hydrangea leaves may turn purple if there is a nutrient deficiency, such as nitrogen or phosphorus. These essential elements are responsible for chlorophyll production, and when they are lacking, the leaves may turn purple or yellow.

Solution: To correct nutrient deficiencies, you should fertilize your hydrangeas with a balanced fertilizer that contains nitrogen, phosphorus, and potassium. You can also add organic matter to the soil, such as compost or manure, to improve soil fertility.

Hydrangea leaves turning purple can be caused by several different factors, including soil pH level, fungal infections, sunlight exposure and temperature, and nutrient deficiencies.

To prevent your hydrangeas from developing purple leaves, it's important to ensure they are planted in the correct type of soil, watered properly, and given adequate amounts of nutrients. Regularly monitoring for signs of disease or stress can also help you catch any problems early on, before they become more serious.

Preventing Hydrangea Leaves from Turning Purple

Here are a few tips to help prevent hydrangea leaves from turning purple:

• Maintain proper soil acidity levels by using fertilizer and/or sulfur or aluminum sulfate to adjust pH levels.
• Water plants early in the day to promote drying and reduce fungal growth.
• Protect plants from intense sunlight and high temperatures by providing partial shade or covering them with a shading cloth.
• Keep an eye on plants for signs of nutrient deficiencies and supplement with appropriate fertilizers as needed.

By following these preventative measures, you can keep your hydrangeas healthy and free from unsightly purple leaves.

Is it normal for hydrangea leaves to turn purple?

No, it's not normal for hydrangea leaves to turn purple. It's a sign of an underlying issue that affects the plant's health.

Does pruning help prevent hydrangea leaf discoloration?

Pruning can help prevent hydrangea leaf discoloration in some cases. Cutting back old or damaged leaves and stems can reduce stress on the plant and promote new growth.

Can too much sun cause hydrangea leaves to turn purple?

Yes, too much sun exposure can cause hydrangea leaves to turn purple. Hydrangeas prefer partial shade and can suffer from sunburn if exposed to direct sunlight for extended periods.

How should I adjust soil pH for my hydrangea if the leaves are turning purple?

If your hydrangea leaves are turning purple, you may need to adjust the soil pH. Adding aluminum sulfate to the soil can lower the pH and encourage blue flower color. If you want pink flowers, adding lime can increase the pH.

What nutrients do hydrangeas need to avoid leaf discoloration?

Hydrangeas need nitrogen, phosphorus, and potassium to avoid leaf discoloration. These nutrients are essential for healthy growth and development.

Can I save a hydrangea plant with purple leaves?

Yes, you can save a hydrangea plant with purple leaves if you address the underlying issue causing the discoloration. Proper watering, fertilization, pruning, and soil pH adjustment can all help improve the plant's health.

Are there any hydrangea varieties naturally have purple or reddish foliage?

Yes, some hydrangea varieties naturally have purple or reddish foliage. Examples include Hydrangea macrophylla 'Pistachio,' which has green and purple leaves, and Hydrangea quercifolia 'Snowflake,' which has dark red-tinged leaves.

Should I be concerned if only a few leaves on my hydrangea plant turn purple?

If only a few leaves on your hydrangea plant turn purple, it's not necessarily cause for concern. However, if the discoloration spreads or persists, it's a sign of an underlying issue that needs to be addressed.

Can over-fertilizing cause leaf discoloration on hydrangeas?

Yes, over-fertilizing can cause leaf discoloration on hydrangeas. Too much fertilizer can lead to nutrient imbalances, which can affect the plant's health.

Can using tap water affect the color of hydrangea leaves?

Using tap water can affect the color of hydrangea leaves if it has a high pH or contains excess minerals. Using filtered or rainwater can help maintain a stable soil pH and prevent leaf discoloration.