It happens even to the best of us — hydrangea leaves turn yellow and we’re faced with the age old question of ‘Why?’ Usually, the problem of hydrangea yellow leaves can be traced back to mistakes in the plant’s care regimen.
In this article, I’ll cover the main causes of yellowing leaves, how to fix yellow leaf issues, and let you in on some tips on how to prevent future occurrences.
Causes of Yellow Hydrangea Leaves
When a hydrangea plant’s leaves turn yellow, it signals one of the following problems:
– Too little or too much light
Hydrangeas grow best in full sun to partial shade. If your hydrangea is exposed to full sun without adequate watering, leaves can become damaged and turn yellow or even brown.
Similarly, if your hydrangea isn’t exposed to enough light and grows only a shady location, the color of its leaves may fade or turn pale.
– Overwatering or dehydration
Green healthy leaves turning yellow because of dehydration or overwater is common in many plants including hydrangeas.
Hydrangeas enjoy moist soil, therefore, dehydration can cause wilting and discoloration of leaves. Overwatering can have the same effect, but unlike dehydration, it’s a sign of something more serious going — rotting of the roots.
– Exposure to low temperatures
Hydrangeas are not frost tolerant and some aren’t even cold tolerant. A sudden temperature drop or a frost can cause the leaves to turn yellow and fall off.
– Soil pH issues
Whether your hydrangeas are planted in the garden or in pots, their soil should be slightly acidic. An alkaline substrate can cause the plant’s leaves to turn yellow.
– Nutritional deficiencies
Lack of nitrogen or iron in the soil can also cause leaf discoloration issues. Nutrients and minerals can become depleted in potted hydrangeas but even in hydrangeas planted in the garden.
Besides these, some hydrangea diseases like chlorosis and gray rot can also cause leaves to change their color.
– Normal aging of leaves
If the problem affects only the leaves at the bottom of the plant, the most likely explanation is the normal aging of these leaves.
How to Fix Yellow Hydrangea Leaves?
Once the leaves of your hydrangeas turn yellow, you can’t change their color back. These leaves are already damaged and they’ll even probably fall off after a while.
What you can do is prevent other leaves from turning yellow, but first you need to identify what caused your hydrangeas to take a bad turn like this.
Since many things come into play, it can be difficult to pinpoint the true cause. Still, the tips below can help you zero in on the problem:
- When leaves turn yellow and fall off, the problem is usually linked to excess watering, cold temperatures or lack of minerals
- If only the edges of the leaves turn yellow, it usually signals a nitrogen of iron deficiency
- Soil pH issues can be identified quickest by testing the pH level of the soil
Fixes for the most common causes of hydrangea leaf discoloration include:
- When planting your hydrangea, make sure that it will get enough sunlight, but without being in full sun all day. Potted plants can be relocated easily, garden planted hydrangeas can be transplanted too, although it can be a bit more difficult.
- Yellow leaves caused by dehydration can be fixed by watering your hydrangea when rainfall is scarce or temperatures are high.
- Yellow leaves caused by overwatering can be fixed by planting your hydrangeas in a location with good soil drainage and making sure the roots don’t sit in waterlogged soil
- An alkaline soil can be amended with soil acidifiers to lower the pH value and create a favorable environment for hydrangeas.
- Nutritional deficiencies appear mostly in hydrangeas that are planted in pots, but even garden hydrangeas require a nutrient boost. For best results, fertilize your hydrangeas 2-3 times during the growing season or once with a slow-release fertilizer.
Leaves that turn yellow because of the normal aging of the plant will be visible usually only on the lower branches. You can remove these leaves and keep the area around the base of the plant clean to improve air circulation.
How to Prevent Yellow Hydrangea Leaves?
Prevention of leaf discoloration in hydrangeas is possible and it starts with making sure you understand the lighting, watering, soil, temperature and fertilizing requirements.
Because multiple things can cause hydrangea leaves to turn pale or yellow, you need to start prevention with the basics:
– Choose a good location
Plant your hydrangea in a spot where light is diffused so that they get enough sunlight without it being too much. Plant in a location with good drainage of the soil. You can also amend the soil for better drainage.
– Develop a good watering routine
Depending on the climate in your area, you may need to pay more attention to watering. If you live in a dry and warm location, you may need to water your hydrangeas every 2-3 days.
I live in a temperate area with plenty of rainfall during spring and summer, so I rarely have to water my hydrangeas. If it gets too warm outside with no rain, I make sure to irrigate.
– Give your hydrangeas a nutrient boost
Correct fertilizing can also go a long way in preventing yellow leaf tips in your hydrangeas. I use organic fertilizers 2-3 times during the growing season to meet the nutritional demands of my hydrangeas.
Growing and blooming equal a higher uptake of nutrients and minerals. And if the soil is deficient in these, you need to supplement them.
Yellow leaves in hydrangeas aren’t usually a cause for immediate concern, but it’s best if you address potential issues early on.
Multiple factors can be blamed for changes in leaf color, but usually the cause is something simple as too much light or not enough water.
The list of causes I presented above can serve as a blueprint to identify the underlying issue and fix the problem as quickly as possible.
With time, you’ll be attuned to your hydrangea’s requirements, and you’ll be able to swiftly solve any emerging issues.