The deep green foliage of the hydrangea is as attractive as the bright bulbs of blooms to many gardeners. Unfortunately, there are numerous issues that plague the delicate equilibrium needed to keep the leaves of the hydrangea lustrous and healthy. Although disease and attacks by insects are common, another problem is one with a variety of explanations – leaves curling.

If someone must ask themselves, “Why are my hydrangea leaves curling?” they might be surprised by some of the answers. At the end of the day, though, causes can be narrowed down to a few factors: water deprivation, disease, and finicky hydrangea plant types.

A Thirsty Hydrangea

As sturdy flowering shrubs, hydrangeas require a lot of water in well-drained and tended to soil to thrive and survive. Curling leaves are often caused by the hydrangea not receiving enough moisture on a regular basis. When this happens, the cells in the leaves start to die, causing them to become dehydrated, turn brown, and eventually curl from damage. Hydrangeas require so much water that their name is actually a combination of two Greek words meaning “water” and “vessel.” Gardeners who think they are watering these shrubs enough are most likely failing in their duties.

Hydrangeas will absorb water quickly, so it’s important to keep the soil around them moist. Soil that remains well-drained is also important. When a hydrangea is brought inside, it needs to be watered sometimes more than once a day. When outside, hydrangeas can sometimes go two days between watering, but it’s best to check the soil regularly to make sure everything is healthy. If drying and curling leaves are a consistent problem, gardeners should pay more attention to their hydrangea’s water levels. To help prevent the hydrangea from drying out, the shrubs should be planted in an area with partial shade and away from heavy winds.

However, be careful about over-watering hydrangeas. An unfortunate problem that occurs is the development of Botrytis or gray mold in hydrangeas when the sepals are kept too damp.

Diseases that may cause leaf curling

Lots of diseases that affect hydrangeas will harm the leaves. In particular, there are root rot, leaf spots, and powdery mildew. The majority of the diseases which harm hydrangeas will not actually kill the hydrangea but can affect its health and appearance. However, they should still be taken seriously. Some of the most common diseases to watch out for are funguses like Armillaria root rot, which will destroy roots and prevent water from reaching the leaves and blooms. Another common problem is the Cercospora fungus, which will attack foliage and cause leaf curling and death. If a disease is believed to be the cause of hydrangea leaves curling, it’s important to treat the issue as soon as possible with a fungicide spray.

Sensitive Specimens

Some varieties of hydrangea are difficult to care for because they are sensitive to the slightest change in the environment around them. Taking care of these specimens is far more of a science than an art because everything has to be precise. Some of the most difficult hydrangeas to take care of are the bigleaf and smooth hydrangeas. Both of these varieties need to have more water than any other style of hydrangea. When exposed to dehydration, the leaves of the bigleaf and smooth hydrangeas will rapidly deteriorate. The leaves curl and the stickers start to decay and turn brown. They thrive when given at least one inch of water a week and even more when the weather is hot and dry.

Many varieties of hydrangea also suffer when exposed to the cold. It’s okay when the hydrangeas are dormant and winter comes, but many types, including the aforementioned bigleaf and smooth, do not react well to spring freezes and frosts. Gardeners cannot do much to prepare for late spurts of cold weather, and the return of wintery days can toll the end of hydrangea blooms and cause leaves to start to curl and dry. The most that can be done is trying to keep track of the weather and covering hydrangeas to help protect them from cold snaps when possible with plant protection such as fleece.

Finally, there is the issue of environment. New gardeners don’t consider their soil quality, but experienced individuals know that flowers and other plants won’t grow if they aren’t receiving the right amount of nutrients. It’s crucial to make sure soil possesses enough nitrogen, phosphorous, and potassium to keep hydrangeas happy, healthy, and with uncurled leaves.

Gardeners who don’t want to deal with sensitive specimens should consider investing in more hardy varieties for their garden. One of the best is the panicle hydrangea, which exhibits beautiful pink and white colors and can survive sudden cold snaps. They also don’t need as much water as varieties such as the broadleaf and are not sensitive to pruning.

Pests

If a pest is the cause for a hydrangea leaf curling and turning brown, then it will take a lot of work to get the shrub healthy again. Sometimes leaves start to curl from damage at a cellular level caused by aphids and other unpleasant insects chewing away at the leaves while they are young. This damages disconnects crucial pathways in the leaves that allow for the spread of water and nutrients.

Gardeners who suspect that pests like aphids might be to blame for curling leaves should carefully examine their hydrangeas. Check for holes or corrosion caused by insects eating and their damaging saliva. If some are found, try applying a pest treatment to effected plants. To improve the appearance of the hydrangea, carefully prune and trim away the curled and dying leaves to make room for new ones to grow.

Conclusion

Hydrangea leaves curling happens for a variety of reasons and isn’t always a cause for concern. In the majority of cases, it just means the plant needs more water on a regular basis. If that doesn’t work, make sure the soil and surrounding environment provides the proper amount of sunlight and nutrients. If problems continue, it’s time to look into more concerning causes such as disease and pests. If these are to blame, quick action is needed to save the hydrangea from becoming food for unwanted visitors.

Last update on 2024-11-22 / Affiliate links / Images from Amazon Product Advertising API