Hydrangea is an easy-to-grow houseplant. The colorful hydrangea flowers look extremely beautiful. But there is one problem with hydrangeas that is yellow hydrangea leaves.
Hydrangea leaves turning yellow can be fixed with little changes in the plant care routine. It does not matter the entire hydrangea leaf is yellow or the edges are yellow with spots. Yellow leaves mean your plant is in serious problem.
You need to fix the problem soon or all the leaves will turn yellow then drop from the plant.
Below are the all-possible reasons that are responsible for turning hydrangea leaves into yellow color.
Hydrangea leaves turning yellow is a common problem. You should take the right actions in the initial stage or you will lose your plant. There are many conditions that turn the green leaves into yellow leaves.
All the causes are listed below with their solutions.
Extra bright light
The extra bright light causes leaf scorch in hydrangeas. No doubt they need light to produce colorful flowers. But the light has to be low-intensity light. Only the morning light is good for hydrangeas. Protect them from direct sun rays from 10 am to 4 pm.
If the top and side leaves of the plants are yellow. The 100% problem is extreme light that is not tolerable for the plant.
To fix the problem change the location of the plant pot. Put it in a little shady place where the light is less bright.
In case you are growing it under the grow light. You should install it a little high over the plant. The light should be minimum of 24 inches above the plant. Do not use HPS grow lights they will burn your delicate hydrangeas. LED grow lights are best for soft tissue plants.
The ideal temperature is between 18 to 24 degrees C. In winters when the temperature inside the house starts to drop below 18 degrees C. The hydrangea leaves start turning yellow. Try to maintain the temperature of your home between the optimum temperature range.
First, the leaves of hydrangea start to turn pale after that they turn yellow.
You should catch the problem in the first stage (pale leaves).
For your plant safety install a temperature monitor in the grow room. And set the min and max temperature in it.
Temperature above 24 degrees C also turns green leaves into yellow color. But on the next day, you will see brown tips. This indicates that the temperature is above the range and your plant is uncomfortable.
Overwatering and incorrect plant pot
Overwatering is the easy-to-control issue that causes Hydrangea leaves turning yellow from green. Your plant pot can save your plants from extra water. Use the latest pots with a draining hole at the bottom that allows extra water to go out of the pot. This way the pot saves plants from accidental overwatering.
If your plant the container does not have a bottom hole. Then the given water gets collected at the base of the pot and clog the roots. This makes the soil soggy and heavy that blocks nutrient absorption. They start to turn yellow and droopy.
If 50 % of the plant leaves turn yellow then repotting is necessary. Take the plant out of its pot and through the soil. Then wash the pot with any soap and put it (only plant pot) in sunlight for 2 hours.
Then use the new potting soil in the same pot and plant your plant in it and give some water. But before that remove the yellow leaves. Also cut and through the infected parts of the root ball.
This way the plant saves a huge amount of energy that it spends to produce new leaves and roots.
Dry potting soil
As I said Hydrangea needs constantly moist soil to grow and they can also tolerate a few dry conditions. But when the growers do not give it water for days then the soil becomes completely dry. This dry soil triggers the yellow leaves.
When there is no moisture left in the soil. The plant starts using moisture stored in leaves. This causes yellow leaves in Hydrangea plants.
Follow the correct watering technique to avoid Hydrangea leaves turning yellow. Check the soil, the top 2 inches of the soil has to be dry before watering. Then pour some clean water. Do not use tap water. It may contain heavy minerals that can clog the roots. Use filtered water that you use for drinking.
If the soil is on the alkaline side, then you cannot stop Hydrangea leaves from turning yellow. You need to correct the pH of the alkaline soil. To do so add 4 ml citric acid to the 1 liter of the water. Then use this water to water your plants.
Or you can add lime to make the soil slightly acidic.
5.5 to 6.5 pH is suitable for growing and caring Hydrangeas.
Correct pH is necessary for hydroponic systems.
Fewer Nutrients and Minerals
Nutrient deficiency is the least common factor responsible for Hydrangea leaves turning yellow. The soil in the pot contains limited nutrients. When the plant absorbs all the nutrients then the soil becomes depleted. In short, it loses its fertility.
To make it fertile and usable again you need to use liquid fertilizers.
Organic fertilizers are best for plants. They do not contain any chemicals. Synthetic nutrients are equally good for the plants. But they are fast-acting nutrients and are suitable for heavy feeder plants.
Organic once releases nutrients at a slower rate. This makes a chain reaction and plants have nutrients available for a long time.
Loss of Iron
If the veins in the leaves are green but the leaf is yellow. Then this indicates the deficiency of IRON. Discoloration of Hydrangea leaves is possible with loss of iron.
This problem is rare and only triggers when the plant is watered with hard water. Get check your tap water from local water authorities.
Or change it and use filtered water. But only changing the water will not correct the issue. You have to use iron-rich supplements for short time.
Once the leaves become green stop the iron supplement and continue the use of filtered water.
Weak roots mean weak plants and it is only possible if you totally neglect your Hydrangeas. Improper care routine weakens the plant roots.
They become unable to absorb the nutrients from the water and soil. This results in Hydrangea leaves turning yellow and then brown.
After some days the leaves start dropping from the plant dies.
To fix this follow the best care guide from day one. And check the pH of the soil and give some organic nutrients. Place the plant pot in ideal growing conditions until it starts recovery signs.
Should I stop giving nutrients?
No, Because the nutrient deficiency is also caused Hydrangea leaves to turn yellow in 3 to 4 days. You need to use the nitrogen-rich supplement to boost plant health.
Use it in the springtime because it is the Hydrangeas growing time. This will not only save your plant leaves. In fact, you will have a beautiful heavy bloom.
Your nutrient bottle should have trace elements along with major elements like Nitrogen, Phosphorous, and Potassium.
Can I prevent Hydrangea leaves from turning yellow?
Yes, you can prevent yellow leaves in Hydrangeas if you give them proper care. They do not need much care. Just give them 3 to 4 minutes of your day and they will thrive beautifully.
Use nitrogen-rich supplements and clean drinkable water.
Put the plant pot in the indirect bright place.
Use a plant pot that has a bottom hole
Do not use plastic and ceramic pots
Use clay or terra cotta pots, they are made from pours material
Monitor the temperature of the grow room
Test the pH of the soil
Do not use garden soil because it becomes heavy when used in plant pots.
Use commercial potting soil with well-draining properties.
Follow the best care guide
Keep eye on the plant
Use neem oil and water spray on the plant once a month
Keep the plant pot and surroundings hygienic and clean.
Take care of humidity, group the plant when needed.
Hydrangea leaves turning yellow or brown is a common problem. All above-listed methods are tried and tested by professional growers. For more info on Hydrangea yellow leaves contact us.