3 Reasons For Lilac Leaves Curling [How To Fix]

When the lilac’s leaves are curling, it can be an early sign of fewer blooms in the flowering season. And as a lilac grower, this is a very concerning issue. But if you take the right actions, the blooming won’t be much affected.

Leaf curling is a very common problem for lilacs. While this may look like a normal thing, sometimes it can be a fatal problem. Especially if your lilacs are newly planted. So, what causes curling on the leaves of the lilacs?

There are 3 reasons why your lilac leaves are curling. They are Pest Problems, Powdery Mildew Disease, and Underwatering issues.

In this article, I have discussed all the reasons for the lilac leaves curling. Keep reading to find out what are the easy solutions to this leaf curl.

 So let’s get down to business-

Why Are the Lilac Leaves Curling? 

1. Lilac Pest Problems

Leaf miners are a common pest of lilac. They get inside of the leaves and weaken the leaf structure. As a result, the leaves start curling and turning brown. When the infestation is severe the whole plant gets affected.

Treating the leafminers at an early stage is very important because they make the lilacs susceptible to other pests and diseases.

Control Measure

Applying an insecticide is necessary to get rid of the leaf miners. But be careful while choosing, because some of them contain harmful chemicals. Pick the best insecticide to control the leaf miners in your lilac plant (our pick: Monterey organic Garden Insect Spray)

Cut off the damaged leaves and let the new growth take its place. Apply neem oil and horticultural oil, especially during the spring to kill the eggs of leafminers.

 Here are some easy, helpful and effective homemade insecticide recipes you can try :

 #Recipe 1:- Horticultural Oil Recipe


  • 1 tablespoon of liquid dish soap 
  • 1 cup of any oil like soybean oil or olive oil or vegetable oil. 


  • Mix these ingredients very well.
  • And store the mixture in a bottle.
  • Add one tablespoon of this mixture with every cup of water and pour it into the sprayer.
  • Spray this every week on your lilac leaves.

#Recipe 2:- Neem Oil Recipe


  • 1 tablespoon of neem oil 
  • 2 liters of water 


  • Mix the ingredients and spray on the plants every week.
  • Apply this on your lilacs on a regular basis as a preventive measure.

#Recipe 3:- Tomato Leaf Spray Recipe


  • 2 cups of fresh tomato leaves
  • 3 cups of water


  • Chop the tomato leaves 
  • Let them stay overnight in a cup of water. 
  • Then strain out all the leaves and add another cup of water to dilute the solution. 
  • Spray on the lilac’s curled leaves twice a week.

Note: For all homemade recipes, always use a small portion of the mixture in a small area of the lilac plant. Wait out to see how it reacts before starting to apply in bulk. If the lilac leaves burn or wilt then you can skip spraying the mixture. Or you can just dilute the solution to make a milder mixture and try again. 

 Also, do not apply any insecticide or fungicide during hot and dry periods. This can burn the leaves and turn them black.

2. Powdery mildew

Powdery mildew is a fungus that attacks lilac in some specific conditions like warm and humid weather with 60-70 F temperature. When the lilacs are planted very close to one another and stay in shaded conditions powdery mildew attacks very dangerously.

 The leaves get a very ugly appearance with powdery substance all over them. And it looks like flour is dusted over them. The leaves also start curling, wilting, and falling off.  If powdery mildew is not fixed soon the lilacs suffer a lot. It can even die.

Control Measure

Start by removing all the wilted lilac leaves. After that apply the best fungicide to your lilacs that is non-toxic to humans and animals (Our Pick: Bonide Copper Fungicide).

Also, I’ve added some practical homemade fungicide recipes that you can try for powdery mildew treatment:

# Recipe 1- Baking Soda Spray Recipe


  • Baking Soda 1 teaspoon
  • Few drops of liquid dish soap
  • 1 liter of water


  • Mix the ingredients well and spray thoroughly on both sides of the diseased lilac leaves.

#Recipe 2- Vinegar Spray Recipe


  • 1 tablespoon of apple cider vinegar 
  • 2 liters of water
  • Few drops of liquid soap


  • Mix the ingredients very well and spray on the infected lilac leaves twice a week.

# Recipe 3- Epsom Salt Spray Recipe


  • Half a tablespoon of Epsom salt 
  • 1 liter of water


  • Mix very well.
  • You can spray this solution on your lilacs every week.
  • This solution works as a fungicide and also helps in blooming.

Preventive Measure

Fungal diseases spread very fast through water movement. To prevent further fungal attacks, water the plants from the base. Water early in the morning. And avoid wetting the leaves. 

Keep enough gaps between each lilac plant for better airflow. Prune off the infected droopy lilac leaves that have black or white spots. Remove the severely infected branches to slow down the infection.

Make sure they are getting enough sunlight. You can also thin out some branches to provide air circulation.

3. Underwatering

When the lilac bush is underwatered the leaves curl to preserve the moisture. If this situation goes on the leaves also start turning yellow and drying. When the lilacs are continuously underwatered, their leaves turn brown around the edges. Check the lilac soil with a moisture meter to avoid underwatering issues (Our pick: Atree Soil Soil Tester Kits with Moisture, Light, and PH Test for Garden)

Control Measure

You need to keep the soil moist but not overwatered. Water the lilacs enough when the weather is too hot. But do not keep watering too much. Because it can bring another fungal problem called root rot. Also, make sure the soil is well-draining.


 When your lilac leaves are curling don’t delay in taking action. Sometimes there can be several issues making them curl at the same time. 

Be sure to provide them with enough water and sunlight. Fertilize to keep them healthy. And don’t forget to treat them with the best pesticide and fungicide from time to time.

In this article, I have tried to provide all the necessary information. I hope this helped you fix the curling problems of your lilac bush.

All the measures in this article apply to any of your lilac varieties such as Japanese lilac, Bloomerang lilac, Ivory silk lilac, Miss Kim lilac, Texas lilac, Sensation lilac, etc.

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