How To Prevent Lilac Bushes From Turning Brown

The Lilac plant is a deciduous plant with green leaves opposite its stems. It is known for being a flowering plant that makes shrubs or bushes. This plant can help you create a landscape or be used to make fragrances. 

Even though lilac is a tough plant that can grow over the years, it is bound to face some changes, such as its leaves turning brown. If you are wondering what is causing the leaves to turn brown and how to prevent lilac bushes from turning brown, we will help you unravel this problem and the possible solutions. 

Throughout the article, we will discuss what causes the lilac leaves to turn brown and how to prevent them from turning brown to ensure you have a healthy growing plant. 

What causes lilac leaves to turn brown?

If you want to solve an occurring problem, you must first understand what is causing the problem. For the lilac plant, this problem has several reasons as to why it is happening. The common reasons include the scorching sun, branches dying, and poor watering techniques. 

Too much sunlight

That doesn’t mean direct exposure to the sun. For lilacs, when exposed to too much sunlight, start having spots on their leaves. These spots indicate that the sun is burning the leaves. 

If your plant is getting too much sunlight, you can prune extra leaves to leave enough space for air circulation and move it to an area with shade. The best place to plant a lilac plant is in a bright place with exposure to indirect sunlight. 

Bacterial blight

Bacteria blight, also known as shoot or Blossom blight, is a disease caused by bacteria known as Pseudomonas syringae. It attacks the leaves and stems of the plant. 

Once it affects your plant, you can notice symptoms such as leaves turning brown, dark spots, wilting, and dropping. The dark spots appear like the leaves have been burnt with a flame. 

Mildews fungal disease

Mildew fungal is another disease that causes leaf discoloration on the lilac bushes. The disease is caused by Erysiphe cichoracearum, a fungus that affects both leaves and stems. After affecting the plant, you can notice symptoms such as white or gray powder on the leaves. 

To control this disease, prune the affected leaves and stems. 

Too much nitrogen

Applying too much nitrogen can have effects on your lilac plant. For young species yet to mature, the fertilizer can result in diseases, while for plants that have matured, it causes the leaves to turn brown. The leaves turn brown because the branches of the bushes are dying. 

You can trim off all the mature stems until you remove the dead tissue from the plant. If you don’t remove all the dead tissue, it can start spreading again after some time. 

Lilac bushes are old.

When lilac leaves become old and start to die, the leaves will start to turn brown because of the dead tissue. At this point, the lilac plant has served its purpose, and you can leave it to die or try pruning the old and dying leaves. 

Cold temperatures

Climate change can cause the lilac leaves to turn brown. Since the lilac grows well in warm temperatures, the plant gets stressed if it’s exposed to cold temperatures, causing the leaves to turn brown. Another problem can be a result of the sudden changes in temperatures. 

Nutrient deficiencies

The lack of nutrients in plants, such as nitrogen, phosphorous, or potassium, can cause the leaves to turn brown. Without sufficient nutrients, the plant will likely die. However, nutrient deficiencies will cause leaf discoloration, stunted growth, and flower deformities in this case. 

Try adding fertilizer to the plant to balance the number of nutrients in the soil. 

Exposure to chemicals

Lilac bushes may not work well with some herbicides and insecticides. Some of these chemicals, once you apply them to the leaves, it causes them to turn brown. It can be because the chemicals are concentrated and burn the leaves, causing leaf discoloration. 

If it starts causing this problem, wash the leaves with clean water to remove the chemicals, and then use another type of chemical to spray your plants. 


Giving little water to the plant is a significant problem that gardeners face. The lilac plant requires that it has enough water and that the soil is moist. If it doesn’t have enough water, the plant starts to dry, and the leaves turn brown.  

To make sure the plant has enough water, try to stick your finger an inch into the soil to check if the soil is moist, then water the plant. You can also create a watering schedule to ensure you don’t overwater or underwater your plant.

How to prevent lilac bushes from turning brown

Treat bacterial blight

When your plant shows symptoms of bacterial blight, start the preventive measures immediately to avoid spreading to other areas. The best thing to do is to prune all the parts affected by the disease. 

Ensure that you remove all the parts that have the disease, including the stem tissues. If you don’t remove all the affected parts, it can start affecting other parts, and eventually, the plant will die.  

Proper care for the plant

Caring for the plant involves watering properly, pruning it, placing it in the sun, and ensuring the weather doesn’t affect it. The lilac bushes won’t turn brown if all these are done perfectly. 

When you water your plant, ensure you always make the soil moist. But you have to make sure it is not wet or dry. During the summer, you can use extra water, while during the cold season, you can use little water. Use the finger technique to ensure the roots have enough water.

When it comes to pruning your plant, it is unnecessary to prune except when needed. On such occasions, it can be due to disease, scorching sun, or some other factor causing the leaves to turn brown. However, if none of these occasions arise, you can prune it once a year because pruning causes stress to the plant. 

You can prune older leaves and branches that are starting to die. The dying stem causes the leaves to turn brown. Removing old stems leaves space for new branches to grow and improves the airflow between the branches. 

Fertilize properly

When you fertilize a plant, whether using compost or bought fertilizer, a certain amount is required for each space. Without proper guidance, you can over-fertilize or under-fertilize. In both cases, it significantly affects the plant’s growth. 

When you under-fertilize, the plant will lack enough nutrients to feed itself as it grows, and once it reaches a certain level of growth, it will start to wilt because of the lack of nutrients, and the leaves will turn brown. On the other hand, if you over-fertilize, the plant will have more nutrients, but the nutrients can attract insects and fungi, which cause diseases in the plant. 

The best way to fertilize is to either follow instructions per acre or ask for guidance when buying the fertilizer.  

Proper exposure to sunlight

Most lilac plants are grown in areas exposed to direct sunlight because that’s where they work fine. However, if you place them in these areas, ensure they receive 6 to 8 hours of sunlight to avoid the sun burning the leaves. Also, it depends on the intensity of the sun in your area. 

Ensure the plant receives enough light for it to be healthy. You can place it near a window that receives sunlight through the day, or you can provide lighting. For those who have the plant indoors, it can also survive in the shade, but it requires exposure to indirect sunlight for it to grow. 

Weather changes

Since sudden weather changes can cause brown bushes, you need to be aware of the changes in weather conditions. That is, from dry and warm conditions to wet and cold. If your plant leaves are brown because of the weather changes, you may be forced to cut about six to eight inches off the plant for it to regrow back.   


Throughout the article, we have highlighted the problems and the solutions to help you as you plant your lilac. Some problems are caused by nature while others are caused by us farmers, so ensure that you check before you start the preventive measures. 

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