Why Hydrangea Leaves Turn Yellow + How to Fix Them

Hydrangea leaves are usually green when healthy, and the flowers very colorful and attractive. But one of the telling signs that something is wrong with this plant is when hydrangea leaves start to turn yellow? What are the causes of yellowing and how can you fix it?

Hydrangea leaves turn yellow due to overwatering, too much direct sunlight, or nutrient deficiency. To fix the yellow leaves, move the plant to a shaded area and drain excess water from the pot. Feed the plant with an iron supplement and nitrogen fertilizer to keep leaves green and healthy.

Hydrangeas are great plants especially if you choose a hardy variety that can grow even in zone 3 and tolerate even zone 8 and withstand even some cold winter temperatures.

What causes hydrangea leaves to turn yellow?

Hydrangea leaves turning yellow - why
Why are your hydrangea leaves discoloring?

Hydrangea leaves serve as a backdrop for the beautiful flowers, so when the leaves start to discolor by turning yellow, it messes up the beauty of the whole plant. Sometimes, plants like limelight hydrangeas lose color and appear to change the esthetic of the garden.

Here are the possible causes of yellow leaves on hydrangea plants:

Overwatering

Overwatering is the main cause of yellowing leaves in hydrangea plants. This plant prefers well draining soil that’s kept moist all the time. If the pot is not draining properly, the leaves will start to turn yellow and droopy.

Also, too much water leaves the plant soggy, drenched in the root area, and unable to breathe. Stunted growth, root rot fungal disease, and leaf discoloration will follow soon.

Wrong watering could be a reason why hydrangea leaves turn yellow. In as much as hydrangea plants love water, they will not grow and thrive in wetlands. The roots will start rotting because of the constant wetness, and then you will see the leaves slowly turning yellow.

If proper care is not taken, the entire plant may die.

Underwatering

The symptoms of underwatering are much similar to those of overwatering in hydrangea plants. Inadequate moisture causes wilting, yellowing and droopy plants.

Underwatering can come down to poor watering schedules. If you go more than one week before watering your hydrangea, you’ll see leaf discoloration as a major symptom.

The best fix for this is to make sure the potting mix is well-draining and that you keep the root zone of the plant moist without overwatering it. Water once a week but don’t soak the plant.

Fungal disease

Fungal infections on houseplants show signs on the roots and leaves of the plant. Root rot, for instance, makes the plant unable to feed properly and the signs will start to show on the roots as well as on the leaves.

Drooping and yellowing leaves in hydrangea could be a sign of root rot fungal disease, which, if not taken care of can leave the plant dying.

Another common problem is leaf spot, a fungal disease that can manifest as yellow leaves and brown or purple spots on the leaves of hydrangea, especially on the underside.

Leaf scorch from too much light

If hydrangea leaves turn yellow, especially after wilting, the problem might be leaf scorch. Yellowing from too much light is common if the affected leaves are positioned in a way that they receive direct sunlight.

Hydrangeas prefer partial sun, meaning if you expose the plant to full-day sunlight, the leaves will start to droop and turn yellow. Sometimes, hydrangea leaves will start to turn brown and form spots of discoloration due to scorching sun.

Iron deficiency

Iron chlorosis causes hydrangea leaves to turn yellow
Iron chlorosis causes hydrangea leaves to turn yellow with green veins.

Yellowing hydrangea leaves can indicate iron deficiency. Iron is an important nutrient for the greening of leaves and other parts of the plant. The discoloration that occurs in plants due to iron deficiency is called iron chlorosis.

Iron chlorosis simply means that the hydrangea plant is not getting enough iron. Iron deficiency in hydrangea is characterized by the following:

  • Intervenial chlorosis – leaves turn yellow while the veins remain green.
  • The yellowing is more evident on the new and expanding leaves.

If the plant’s new leaf turns yellow but has green veins, you should suspect iron chlorosis. Such a disorder occurs when you water the plants with hard water. The good news is that iron deficiency can be fixed easily by feeding the plant with some potent iron chelates in the pot.

More on this in the next section.

Nitrogen deficiency

The signs of nitrogen deficiency in hydrangea include lower, older leaves turning light yellow and the entire plant growing slower than usual.

Nitrogen deficiency is easy to fix, but you need to determine why the nutrient is not adequate. For example, if you fertilize your plant with a good indoor plant fertilizer yet the leaves are turning yellow, it is possible that the nutrients are being flushed out of the pot possibly due to overwatering and drainage holes being too big.

How to Fix Leaf Yellowing in Hydrangea

We all know the hydrangea as this amazing plant with beautiful flowers. That is because it is not known for its foliage; rather, it is the blossoms people are interested in.

If the leaves are starting to turn yellow and discolor, here’s what you can do to fix the plant and stop the yellowing:

1. Provide partial sunlight

Apart from preferring well-draining soil and with plenty of moisture in the root zone, hydrangeas like partial sun. To fix the yellowing leaf problem, place your hydrangea plants where they receive full morning sun and stay in the shade the entire afternoon. 3 to 6 hours of direct morning sunlight is enough for hydrangea plants.

Keep in mind the scorching midday and afternoon sun can cause hydrangea leaves to lose water excessively, droop, wilt, and suffer from curling leaves.

If the problem is the lack of light or excessive lighting, you should place it in a place where it will receive the afternoon sun. You should note that the UV radiation is harmful to the plant when it receives sunlight for 11 to 15 hours.

The spot that you pick should enable the plant to receive 6 hours of the afternoon sun. If not, the plant could get a severe sunburn.

You should also be aware that the hydrangea plant does not thrive in dark places either. The plant will not grow well if it is overshadowed by other tall plants or any other big shrub.

2. Feed hydrangea with iron supplements

The first thing you want to do is determine that iron deficiency is what’s causing the chlorosis. If so, supplement the deficient iron using iron chelates. When feeding the plant to fix iron deficiency and stop the yellowing, do not overwater the plant.

Overwatering will flush out the nutrients and leave the soil in the pot with inadequate nutrients to feed hydrangeas for healthy leaves and flowers.

3. Maintain proper water moisture level

The fix to yellowing due to overwatering and overwatering is to make sure that the soil always has enough water/moisture. If the problem is dry soil, the leaves will turn yellow and fall off. So what should you do in this case?

  • You should not let the soil dry completely.
  • Always water your plant once a week, but be careful not to wet the soil or make it soggy.
  • Mulching is also recommended to retain moisture.

If the soil is already too wet, you might want to repot the plant to fix the waterlogging problem that’s causing the leaf discoloration and fungal diseases.

If the problem is wrong watering, you should minimize the frequency in which you water the plant. You could even stop watering the plant altogether if the place you have planted the hydrangea is constantly wet.

You can also protect the hydrangea plant from being water-logged by using a drainage layer made of either stone or broken bricks at the bottom of the bucket or pot. The layers should be put before planting or when transplanting.

If you ever find yourself in a situation where you overwater a hydrangea plant, do not panic. Just follow these guidelines, and everything will be fine.

4. Use mineral fertilizers and iron supplements

If the problem is a lack of nutrients, you should fertilize the soil in which the hydrangea plants are growing in. Add mineral fertilizers to the soil, and do not forget to add manure during planting.

An iron-rich fertilizer such as Milorganite is great to help get rid of iron chlorosis and signs of nitrogen deficiency. If you’re not in need of nitrogen fertilizer, you can use an iron supplement such as Ironite to fix the iron deficiency

5. Fix the soil pH

If the problem is low soil acidity, the leaves will turn yellow. The recommended pH for growing hydrangeas is 5.5-6.5. If the soil is not acidic enough, for instance, you could quickly correct the pH by watering it with a solution of citric acid and water

How to save overwatered hydrangea

Even though water is a requirement for plant growth, it is best to know how to use it. This is so that you do not negatively affect your plant with too much or too little water.

We have all been there at one point where we thought that when we give our plant more water, the more chances it has for surviving. Well, that is not necessarily true, especially for the hydrangea plant. This is because it will only leave you with an overwatered plant.

Below is a step by step guide on how to save an already overwatered hydrangea;

  1. Repot the plant- for you to assess how badly the roots are damaged, this is the first step you have to do. Shake off the excess soil to expose the roots.  Cut off the rotted roots and replant your hydrangea with fresh soil.
  2. Relocate the plant- this will aid in preventing wilting as a result of direct contact with the sun.
  3. Remove damaged leaves- the yellow leaves will be full of dead cells that won’t assist the plant in any way. So it is best if they are cut off.
  4. Treat the soil with a fungicide- and finally, you are advised to treat your soil with a fungicide because molds usually develop in a wet environment.

What to Do When Leaves are Falling Off

Fixing the problem of yellow leaves is not so different from fixing the problem of falling yellow leaves. Both of these issues could have the same underlying causes and solutions, and more often than not, they are synonymous.

If you follow the tips highlighted above, there is no reason why your beautiful plant should not spring back to life.

Should you cut off yellow leaves?

Yes! You should cut off the yellow leaves. Even though you would want to keep the leaves of your hydrangea plant, it is important for you to prune them down,

As earlier stated, yellow leaves do not serve the plant because they are composed of dead cells. They will also destroy the overall look of your hydrangea plant.

You are advised to cut off the affected leaves with scissors or pruning shears to give space for new leaves to thrive.

Ensuring that your hydrangea plant remains healthy and beautiful is not that hard. You just need to know how to take care of your plant correctly. You should also not neglect the preventive measures.

In line with taking care of hydrangea, one should get rid of yellow leaves as they are not attractive at all. Once you have identified the cause of the yellow leaves, you can reverse the problem using the methods we have just talked about. I hope you have learned a thing or two, happy gardening!