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6 Reasons Why Are My Hydrangea Leaves Turning Yellow? + Appropriate Solutions

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Hydrangea is a flowering plant that blooms in spring and summer and often leaves you wondering why are my hydrangea leaves turning yellow?.’ It is considered to be a shrub, but it is known for its ability to bring a burst of color to your garden.

Hydrangeas can reach 15 feet in height, and it grows quickly. It’ll fill up a space in just one summer. These are a great option for you if you’re looking for beautiful, colorful perennials.

Even though hydrangeas are known for their beautiful flowers, their leaves are showstoppers too.  Hydrangea produces bright green leaves when it is healthy. As soon as the hydrangea leaves start to turn yellow, there is a problem.

So if you’re asking yourself the question, ‘why are my hydrangea leaves turning yellow?’, you’re in the right place.

Why Are My Hydrangea Leaves Turning Yellow
What is wrong with my hydrangea tree? Leaves turning yellow on the inner part. – via Reddit

Why Are My Hydrangea Leaves Turning Yellow

There might be many reasons behind ‘why are my hydrangea leaves turning yellow?.’ With enough vigilance, you’ll be able to detect them. And once you’ve identified the problem, you can fix it. The following are some reasons why your hydrangea leaves might be turning yellow:


Too much water is a prominent cause of yellow leaves in hydrangea. Your hydrangea plant prefers well-drained, moist soil. If the pot has poor drainage, or your soil is flooded, the leaves will start to turn yellow.

Overwatering makes the soil soggy. Flooded and soggy soil can lead to stunted growth, leaf discoloration, and, worst of all, rot fungal diseases.


Even though over-watering can be harmful, under-watering is not an option either. Without the much-needed moisture, the leaves will start to lose their color. If you don’t water your hydrangea plant for more than a week, the leaves will start turning yellow.

Fungal Disease

Fungal diseases that attack the plants tend to show signs on the roots and the leaves of the plant. One of these diseases is root rot, which makes it difficult for the plant to feed properly. Due to a lack of nutritional intake, roots will lose their shape, and the leaves will discolorize and droop.

Root rot happens when pathogens take up the root cells as hosts and stop the cell from functioning. If not taken care of, this disease can eventually lead to the plant dying.

Leaf spot is another fungal disease that can target hydrangea. It results in the leaves turning yellow and the appearance of brown and purple spots on the leaves.

Too Much Light

If your leaves started to wilt, before turning yellow, the probable cause is excessive light. Hydrangeas are plants that prefer partial sunlight. If you expose them to bright and direct sunlight, for the whole day, the leaves will start to droop, wilt, turn yellow, and eventually, the plant will die. Too much light can also cause brown spots to form on the leaves.

Iron Chlorosis

Iron chlorosis is a condition where the plant will experience discoloration due to iron deficiency. This means that your plant is not getting enough iron.

Watering your plant with hard water causes the plant’s leaves to turn yellow, but the veins will remain green. This condition is called interveinal chlorosis, in which the yellowing is more evident on the newer and growing leaves.

Nitrogen Deficiency

Nitrogen is a primal nutrient for plants. It is used in the construction of amino acids and hence contributes to DNA and RNA production. If the plant isn’t getting enough nitrogen, it will start to exhibit alarming signs. Those signs include stunted growth and the yellowing of lower, older leaves in the plant.

Why Are My Hydrangea Leaves Turning Yellow 2
Hydrangea Leaves Turning Yellow – via Reddit


Now that you’ve detected the problem, you must be looking for appliable and easy solutions for ‘why are my hydrangea leaves turning yellow?.’ We’re here to help you with that. The following are all the ways to prevent and reverse yellowing in leaves:

Provide Partial Sun

Place your plant in a spot where it receives the full morning sun and remains in shade for the afternoon. Hydrangea will thrive in 3 to 6 hours of direct morning sunlight. The scorching afternoon sun will dehydrate the plant, and turn it yellow.

However, a dark place is also not ideal. Without ample sunlight, your plant will experience stunted growth.

Iron Supplements

If your plant is experiencing iron deficiency, you can feed it with iron supplements. The product we’ll recommend is Espoma IT5 Iron Tone Bag. It’s available on Amazon. While using it, avoid over-watering, since over-watering flushes out all the nutrients from the soil.

Espoma Organic Iron-Tone 3-0-3 Organic Fertilizer and Plant Food to Help Correct Iron Deficiency (Chlorosis). 5 lb. Bag. Turns Yellow to Green, Non Staining Iron
  • FOR USE ON: Use Iron-tone organic fertilizer anytime iron deficiency is seen; use for lawns, shrubs, trees, annual and perennial flowers. Will not stain patios or walkways
  • CONTAINS: Iron-tone is a rich blend of the finest organic ingredients enhanced with our exclusive Bio-tone formula; 3-0-3 Fertilizer analysis with 6% iron and 17% Sulfur. Iron-tone is environmentally safe - No sludges or toxic ingredients
  • WHEN / HOW TO USE: Best to use Iron-tone fertilizer at the first sign of iron deficiency which is yellowing of leaves. Iron-tone is ready to use and requires no mixing and will restore deep green color to chlorotic yellow plants
  • FOR ORGANIC GARDENING: Iron-tone is approved for organic gardening; It is a registered Organic Input Material meaning it meets all requirements for organic production
  • MADE IN THE USA: Product of the Espoma Company. The leader in natural organics since 1929.

Proper Watering

Over-watering and under-watering are both harmful to your plant. So make sure you stick with a watering routine that’ll suit your plant. Remember to not let the soil dry out completely and water the plant once a week.

To retain moisture, mulching is recommended. Mulching is adding undecomposed plant material to the soil. These materials include straw and hay.

Mineral Fertilizers

Mineral fertilizers will be the perfect addition to the soil. Milorganite is one of the best fertilizer options for your hydrangea plant. It’s available on Amazon.

Milorganite All-Purpose Eco-Friendly Slow-Release Nitrogen 6-4-0 Fertilizer, 5 Pound Bag - for Lawns, Flowers and Gardens
  • You don’t have to worry about streaks, stripes, or accidentally burning your lawn when you use Milorganite fertilizer!
  • Milorganite contains virtually no salts, so it won’t burn your lawn, trees, shrubs, or plants, even in the hottest temperatures or driest conditions.
  • Milorganite's iron greens without staining. Grass needs iron for the long-lasting, deep, vibrant green lawn you want. Milorganite delivers organically complex iron throughout the feeding period and won’t stain concrete, unlike iron salts in some synthetic fertilizers.
  • Milorganite’s slow-release plant food formula provides nitrogen and other nutrients for up to 8-10 weeks after application and does not need to be watered in. Covers 2,500 Sq. Ft.
  • Milorganite can be safely used in lawns, flowers, shrubs, trees, and fruit and vegetable gardens, promoting strong roots and sturdier stems. It provides the nutrients every garden needs to grow the biggest and greatest abundance.

Maintain the pH

The pH at which hydrangeas will thrive is between 5.5 to 6.5. If your soil isn’t as acidic, water it with a citric acid solution.


In conclusion, if you are facing the dilemma of ‘why are my hydrangea leaves turning yellow?’ there is a problem. The problem can be anything, from nitrogen deficiency to excessive sunlight. But with the help of appropriate care techniques and preventative methods, your plant will be able to live past these hurdles.

By choosing a spot with partial sun, proper watering, maintaining a 5.5 to 6.5 pH, and feeding your hydrangea with iron supplements and mineral fertilizers, your hydrangea will be out of any danger. Products like Milorganite and Espoma IT5 Iron Tone Bag will aid you along the way.

Hopefully, this helped you out. If you have any more questions, leave them down below and we’ll get back to you.

Happy Gardening!