Most often, the reason hydrangea leaves and flowers turn brown is because the leaves are losing more moisture then the roots can draw up. Excess wind saps moisture away from the leaves causing them to turn brown and curl up. Lack of moisture around the roots causes leaves and flowers to turn brown.
Most common reasons for hydrangea leaves and flowers turning brown:
- Hydrangea require the soil to be consistently moist. Dry soil causes the leaves and flowers to turn brown and wilt.
- Excess wind saps moisture from leaves more quickly then the roots can draw up moisture causing the leaves to turn brown and curl up.
- Potted hydrangea leaves and flowers turn brown if the pot is too small and dries out too quickly.
- Too much sun can scorch hydrangea leaves and flowers turning them brown and crispy in appearance.
- Fertilizer burn causes the edges of hydrangea leaves to turn brown.
- A cold snap in Spring can cause the emerging leaves and flower buds to turn brown and mushy.
- Leaf spot fungus from overhead watering can cause brown spots on hydrangea leaves.
Keep reading for why your hydrangea leaves and flowers are turning brown and how to implement the solutions to revive your hydrangea…
Hydrangea Leaves and Flowers Turning Brown and Wilting
The reason for hydrangea leaves and flowers turning brown is because the hydrangea is loosing more water from the leaves then it can draw up at the roots. If the soil around the roots is not consistently moist the hydrangea leaves and flowers turn brown and wilt as a sign of stress.
Too much wind also saps so much moisture from the large surface area of the leaves that even if the soil is moist around the roots. the hydrangea leaves and flowers can still turn brown and curl up as the roots cannot draw up and replace the water loss quick enough from the leaves.
Hydrangeas require soil that retains lots of moisture around the roots.
If they are in dry, sandy or stony soils then water drains too quickly for the hydrangea’s roots to draw up the moisture it needs, which can be the cause of your hydrangea leaves turning brown and wilting.
There is no universal specific guide on watering for hydrangeas as it depends on climate, weather and factors such as the maturity of the hydrangea plant but hydrangeas should be watered (with a thorough watering) as often as required so that the soil is moist.
At the hottest times of the year it may be necessary to water your hydrangea nearly every day (especially if it is in a pot).
To revive hydrangeas with brown leaves and flowers it is necessary to recreate the conditions of the hydrangea’s native environment by planting hydrangeas in moisture retains soil, watering the hydrangea as often as required to keep the soil moist and sheltering the hydrangea from wind which saps moisture.
- Ideally hydrangeas should be planted or transplanted in soil that has been amended with organic matter (compost, leaf mold or well rotted manure) to a depth of 18 inches which is deep enough to accommodate the root system once the hydrangea is mature. This increases the hydrangeas resistance to drought and therefore decreases the risk of leaves and flowers turning brown.
- If it is not practical to replant your hydrangea then it is imperative to give the soil a thorough watering, ideally with a hose to ensure the soil around your hydrangea is evenly moist to a really good depth, as hydrangea roots are extensive.
- Always give the hydrangea a really generous soak as this encourages the roots to grow deeper in the soil to access the moisture which increases its resistance to drought. Watering too lightly results in the hydrangea roots growing near the surface which leaves them vulnerable in Summer and increases the risk of the leaves and flowers turning brown.
- Apply a 2 inch layer mulch (compost, leaf mold or well rotted manure) to the surface of the soil around your hydrangea. The mulch helps to conserve the soils moisture to create the optimal balance of moisture.
- Ensure that your hydrangea is out of the way of wind as it saps too much moisture from the leaves and turns the leaves the flowers brown. Hydrangea grow naturally in woodland so planting hydrangea under a tree is a an effective strategy to increase shelter and provide the right conditions. You can also create more shelter with other plants to buffer the wind or transplant the hydrangea to a more sheltered area of the garden.
You can either cut back any brown leaves and flowers with pruners at any time of year or wait for them to fall naturally.
Although it is important emphasize that a light pruning is best and to caution against any heavy pruning as this can remove the growth from which the flowers are displayed.
I should also emphasize the importance of regular watering and the use of mulch.
Hydrangea naturally have a mulch of fallen leaves on the wood land floor every year which helps conserve moisture so adding a layer of leaf mold or compost can really help to emulate the moisture retentive soils to which hydrangeas are adapted.
Once the hydrangea is growing in its preferred conditions the leaves should stay green, although the flowers usually do not revive and you may have to wait until they bloom the following year.
(Read my article, how to revive a wilting hydrangea).
Potted Hydrangea Leaves and Flowers Turning Brown
The reason for potted hydrangea leaves turning brown are largely the same as why any hydrangea turns brown.
However there are a few characteristics pertaining specifically to growing hydrangeas in pots that can increase the risk of brown leaves and flowers.
Potted hydrangea leaves turn brown most often because they are planted in pots that are too small and dry out too quickly. Hydrangea have extensive root systems and a high demand for moisture in the soil. If the soil dries out then the leaves wilt or curl up and turn brown as a sign of stress.
If the pot is too small then it has less capacity for potting soil which retains moisture.
Whenever I see a hydrangea with brown leaves in a pot, I always check the roots as the are usually pot bound and therefore have less access to moisture.
It should be noted that pots also require watering far more often then hydrangea planted in the garden as pots can dry out very quickly on hot days and result in a dying hydrangea.
- Replant the hydrangea in a pot that is at least 12 inches across with the same proportional depth. A pot of this size ensures that the hydrangeas has enough soil for the roots to access the moisture and nutrients they require. However as the hydrangea matures, it is worth checking to see if the roots are pot bound as the root system can be very extensive, in which case plant they hydrangea in an even larger pot.
- Add some leaf mold to the potting mix. Leaf mold has an exceptional capacity to retain moisture (even more so then compost) so it can help ensure the optimal balance of moisture for your potted hydrangea.
- Give your hydrangea a good soak as often as required so that the soil is consistently moist. Water the hydrangea thoroughly, so that excess water trickles from the drainage holes in the base of the pot to ensure the soil is evenly moist and that the water has reached the roots where it is required.
- At the hottest times of year it may be necessary to water potted hydrangeas every day to prevent the leaves turning brown. Hydrangeas have a high demand for moisture because of their large, plentiful leaves. In cooler more temperate climates watering hydrangeas once or twice per week in the Spring and Summer is usually the right amount to achieve the optimal moist soil conditions.
With a larger pot and more frequent watering, the hydrangea should have all the resources it require so that the leaves stay a healthy green rather then turn brown.
Ensure that the pot is in a sheltered area, out of the wind, and in dappled light or morning sun followed by afternoon shade.
Clip back any brown leaves or flowers at anytime or you can leave them for the hydrangea to shed naturally.
Too Much Sun Scorches Hydrangea Leaves and Flowers Brown
Hydrangea leaves and flowers turn brown and scorched if they are in too much sun. Hydrangeas are adapted to living under a tree canopy with dappled light throughout the day and do not tolerate being in full sun which not only scorches the leaves brown but can contribute to drought stress.
Hydrangeas are woodland plants that thrive under trees which protects them from excess wind, sun and frost damage in Winter.
Whilst hydrangeas can grow in full shade, they tend to grow green foliage but with fewer flowers.
They key to growing hydrangeas, (ensuring a good display of flowers and avoid scorching the leaves brown) is to find the optimal balance of sun in your garden.
Typically hydrangeas grow best when in an area of morning sun followed by afternoon shade or in dappled light throughout the day.
This balance of sunlight and shade ensures they hydrangeas has enough energy to produces flowers yet is protected enough from intense sun and heat to prevent the leaves and flowers turning brown and wilting.
To create the optimal balance of sun and shade and avoid the leaves turning brown, you can transplant your hydrangea under a tree to replicate its natural conditions of dappled light or attempt to shade it with some taller plants such as bamboo.
Or you can find a shadier area of the garden. The goal should be to ensure that the hydrangea is shaded during mid day and afternoon when the sun as at its most intense and temperatures are at their highest.
Not only will this prevent the leaves scorching brown but also mitigate drought stress at the hottest times of the day.
Trim back any brown leaves and flowers or wait for the hydrangea to shed them naturally.
Hydrangea Leaves Turning Brown on the Edges (Fertilizer Burn)
If your hydrangea leaves are brown at the edges this is often because of fertilizer burn from using fertilizer too often or in too high concentration. Hydrangeas require a slow release fertilizer as an abundance of nitrogen causes the leaves edges to turn brown as a sign of stress.
Hydrangeas are relatively heavy feeders that grow best in fertile soil and benefit from the use of a fertilizer in the Spring to support healthy growth and display more flowers.
However hydrangeas are very sensitive to over use of fertilizer causing their leaf edges to turn brown and crispy and it can reduce the display of flowers.
This often happens due to lawn fertilizer diluting in heavy rainfall, which then runs off into garden boarders where your hydrangeas is planted.
More is not better when it comes to fertilizer as slightly too much fertilizer can promote foliage growth at the expense of flowers and applied too much or too often results in leaves with brown edges and cause the hydrangea to droop.
The key is find the right kind of fertilizer for hydrangeas.
Personally I recommend miracle-gro all purpose granular fertilizer which contains all the nutrients the hydrangea requires for growth and flower at the right concentration to avoid the leaf edges turning brown.
The granulated formula releases the nutrients slowly to mitigate any risk of fertilizer burn.
(Read my article, why isn’t my hydrangea flowering?)
Cold Weather (Hydrangea Buds and New Growth Turning Brown)
The new leaves and flower buds of hydrangeas turn brown if they are exposed to a late Spring frost or cold Winds. The newly emerging buds and leaves are particularly tender and especially vulnerable to damage from a sudden cold snap, causing the buds to turn brown and die back.
Hydrangeas naturally grow in sheltered areas under trees which buffer and harsh cold winds and creates a more stable micro-climate in which the new flowers can emerge without such a significant threat of frost.
When the new buds and leaves of hydrangeas become frost damaged, the leaves turn brown and the buds can turn to a mushy texture.
It is usually the outer most growth that is most badly affected as it is more exposed to the elements.
Unfortunately the damaged flower buds are not then able to flower and the newly emerging growth most likely will not recover.
Frost damage to hydrangea flower buds and leaves is more prevalent where the hydrangea is more exposed, so plant or transplant your hydrangea to a more shelter part of the garden, by your house or near some other plants and hedges.
Hedgerows in particular are excellent at buffering wind as they provide a wall of protection for your hydrangea and can also help to mitigate the affects of frost.
However once the flower buds and newer leaves have turn brown there is not much you can do to revive them. Therefore cut back any growth that has been damaged by the frost and trim back to healthy growth.
Hydrangeas often have developing flower buds further down each branch which is naturally more protected the the flower buds on the outermost part of the plant and they usually survive a frost.
This means your hydrangea can still flower, although it may be much later and with fewer flowers emerging, so with some patience there should still be some good blooms on display in the Summer.
(Read my article, how to revive a dying hydrangea).
Flowers and Leaves Turning Brown From Overhead Watering
Hydrangea flowers and leaves can turn brown from excessive overhead watering which can damage the delicate flowers and promote the conditions for leaf spot fungus which appears as small brown spots on the hydrangea leaves and can cause the to drop off.
When watering hydrangeas, always water at the base of the plant rather then onto the foliage and flowers. Hydrangeas are hardy enough to tolerate some water on their leaves from rainfall but excessive watering onto the leaves in the Summer is usually what promotes the conditions for leaf spot fungus to spread.
Leaf spot is a fungal disease that does not kill the hydrangea but the stress of the disease can reduce its overall growth and reduce the number of flowers on display.
Eventually the leaves can fall off and its important to clear them up and burn or dispose of them to try to limit the spread of the fungus.
Watering at the base of the hydrangea is an effective way of mitigating the affects of leaf spot fungus and prevents it spreading to other parts of the plant.
The best way to robustly solve the problem as it usually comes back every year, if it is left untreated is to use a fungicide spray and leaves with several applications usually around 14 days in between, although you should always follow the manufacturers in instructions.
(Read my article, why are my hydrangea flowers turning green?)
- Hydrangea leaves and flowers turn brown due to drought, excessive wind and too much sun. Hydrangea prefer to grow in sheltered areas with dappled sun, in moist soils and protected from wind. Not enough moisture around the roots causing the hydrangea leaves and flowers to wilt and turn brown.
- Potted hydrangea leaves and flowers turn brown when they are planted in small pots as smaller pots dry out too quickly for the hydrangeas roots to draw up moisture. Hydrangeas have an extensive roots system and require consistent moisture to prevent the leaves and flowers turning brown.
- Applying too much fertilizer or applying it too often causes the hydrangea’s leaf edges to turn brown and crispy. Hydrangea roots are very sensitive to excess fertilizer so it is important to apply a slow release fertilizer at the start of Spring to prevent the leaf margins turning brown.
- A late frost in Spring can cause the flower buds and emerging foliage growth of hydrangeas to turn brown and mushy. The new growth is tender and more vulnerable to frost damage. Brown, mushy hydrangea flower buds do not develop into flowers and should be cut back.
- Leaf spot fungus causes brown spots on the leaves of hydrangeas and is usually caused by excessive watering on the leaves of the hydrangea. Too much moisture on the leaves promotes the conditions for the fungal disease to thrive, and causes brown spots on the hydrangea with fewer flowers.