Skip to Content

Why Are My Lilac Leaves Curling? (And What to Do About It)

Why Are My Lilac Leaves Curling? (And What to Do About It)

Share this post:

Disclaimer: Some links found on this page might be affiliate links. If you click an affiliate link and make a purchase, I might earn a commission. As an Amazon Associate I earn from qualifying purchases.

Lilac bushes are absolutely beautiful and can brighten up anyone’s yard or garden area, and the wonderful way they smell can catch anyone’s attention instantly.

For the most part, growing lilac isn’t difficult, but like any other living plant, you could still run into problems and you need to know how to resolve them.

A fairly common problem involves the leaves of the lilac bushes, which can sometimes curl and look unhealthy. If you’re curious about what this means and what to do about it, keep reading.

Why Are Curled Leaves a Problem?

Lilac leaves can start to curl due to miner leaf insects

It may sound like curled leaves on a lilac bush are nothing to worry about; after all, curled leaves don’t always make the plant look bad.

In reality, though, curled lilac leaves are usually a sign that something is indeed wrong with the plant, and the sooner you learn what the problem is, the sooner you can do something about it.

Everyone wants a healthy lilac plant, and when you notice curled leaves on your lilac plant, it is usually for one of the following reasons:

  • The leaf miner, an insect that can get inside of the leaves, will weaken the structure of the plant and therefore the leaves will start to curl. If the problem is severe enough, it could affect the leaves on the entire plant.
  • Certain fungal diseases will wound the plant so that it starts to die, resulting in leaves that are curled. One of the most common fungal diseases that produce this result is powdery mildew.

Powdery mildew is a fungus that can result from plantings that are crowded and growing too close together, locations that aren’t getting enough sun and too much shade, and temperatures between 60 and 80 degrees Fahrenheit.

This fungus is sometimes difficult to identify because curling leaves can be caused by other things that aren’t as deadly.

Still, it is important to know what is causing your curled lilac leaves and to treat that cause; otherwise, the problem could continue until the entire plant dies.

What About Using Pesticides?

Using pesticides is a great way to get rid of the leaf miner insects. The reason it is so important is because even though the damage these insects cause is mostly a cosmetic problem, that damage can still make the plant much more susceptible to other diseases in the future that are a lot more deadly.

Keeping your lilac plant healthy and vital is crucial if you want to protect the leaves of the plant and keep them looking good. If you choose to use a pesticide, look for one that contains pyrethroids because these pesticides work best.

In addition, it is important to treat the leaves in the spring with dormant horticultural oils to both kill any eggs that may have remained from the previous season and to prevent further infestations from occurring.

Does Pruning the Lilac Bush Help?

Pruning lilac bushes can help prevent leaf curling

Pruning your lilac bush can indeed help in removing the damage that has occurred so far. This is especially true if signs of other diseases are also present, such as wilted leaves, droopy leaves, or leaves that have either black or brown spots on them.

Look for severely damaged branches and go ahead and remove them. This will drastically slow down the spread of the disease and also encourages new growth to continue.

If you choose to prune your lilac bushes, keep in mind that it is best to take any branches, flowers, and leaves that have been pruned out of the garden entirely, because you won’t want to encourage any diseases to spread to other parts of the lilacs that are healthy and thriving.

Many times, a few simple changes are all you need to bring the lilac bush back to life. Lilacs need sunshine, so if you remove nearby plants and thin out the interior of the lilac, more air will get to the right parts of the bush and therefore the fungus will be destroyed.

Removing the lilac bush and planting it in a place that is sunnier can also help, although this technique can be difficult if the bush is too large.

Remember, lilac bushes need very warm temperatures, some space between each plant, and good airflow to thrive, so make sure your plants are receiving all of these things.

Fungicides May Also Help

Fungicides help because they are often formulated specifically to control diseases such as powdery mildew. They do this by killing the fungal spores and therefore stopping the spread of the disease.

This is important because the more powdery mildew and similar diseases are allowed to spread, the more likely it will take over the entire plant and cause it to die.

In fact, when you combine pruning dead branches with the application of a good fungicide, you can both stop the spread of the disease and encourage new growth to appear, both of which make for a much healthier tree.

Final Thoughts

Curling lilac leaves can be caused by numerous things, but certain insects such as the leaf miner insect and certain diseases such as powdery mildew are two of the most common reasons why this occurs. It could also be a sign that your lilac bush isn’t getting enough water or sunshine.

The problem is that curling leaves can be the sign of something that won’t eventually kill the plant, but you never know for sure. This is why using a pesticide or a fungicide can be a big help, because this will get rid of any disease that is on the plant and enable it to grow healthy and strong.

Again, catching the problem early is important because diseases such as powdery mildew can start off slow but start to spread quickly, which means your lilac bush can die fast without you even realizing what is happening.

Curling leaves on a lilac bush isn’t always just a cosmetic issue, in other words, but they can be the symptom of something a lot more serious. This includes diseases that can eventually kill the plant, which means doing something sooner rather than later is always your best action to take.

Before you go: Now is the perfect time to start tracking your gardening progress, and I created a garden journal to do exactly that. Click the image below to see it in action and to get your own copy.

Share this post:


Friday 2nd of June 2023

Hi Lisa,

Would insecticidal soap work for the curling leaves if it is a leaf miner causing the problem. We are a pesticide free zone at our house.