Are you excited to see lilacs bloom gorgeously for the spring season just around the edge? But seeing lilac leaves turning brown, you may ponder whether the plant would produce any healthy blooms. Then why not retrieve the lush green foliage and bring life to the plant before it’s again time to bloom? There can be many reasons for the lilac leaves to turn brown, and finding the cause is the key to solving the problem your plant may be suffering.
The most common reasons for lilac leaves turning brown are: sunburn, infrequent or improper watering, bacterial Blight, or the leaves may become brown as the branches are old and dying back naturally. Other possible reasons are pest infestation, lack of sunlight, improper fertilization, and poor soil.
You first need to observe your lilac plant, examine the lilac leaves that are turning brown, and then search for the possible cause according to the symptoms. Let’s discuss some signs, probable causes, and ways to make the plant healthy again.
Lilac Leaves Turning Brown And Falling Off
If the lilac plant suffers from Bacterial Blight, the leaves turn brown and die. Bacterial Blight infection first comes out during spring and infects all varieties of lilacs, but the white types are most prone to this disease. Bacterial Blight spreads quickly during the monsoon season. The disease-causing bacteria enter the plant through wounds or natural openings and live in the soil and debris.
How To Identify Bacterial Blight On The Lilac Bush?
First, you will see olive-green spots on the water-soaked areas, and then small, brown spots form on the leaves. These spots have yellow boundaries, which distort the foliage, and the branches start to die back. The other signs of Bacterial Blight are:
- The younger leaves twist and curl
- The stems and leaves have brown spots in the spring
- Flowers wilt and turn black
- Unopened flower buds turn black and die
- When the disease progresses, the leaves that turned brown earlier start to turn black
How to Treat Bacterial Blight?
Even though lilacs are hardy plants, fungal diseases affect them and may even kill them. If you see a lilac plant suffering from Bacterial Blight, then do the following:
If Bacterial Blight is in its starting phase, prune the plant aggressively. Cut back the parts you see are affected so the disease doesn’t spread any further.
Dip the scissors in a 10% bleach solution while pruning and cut off at least 12 inches below the point where you see blight infection.
Remove the leaf debris from your garden occasionally, and give appropriate spaces between the plants for proper ventilation.
Planting disease-resistant or bacterial Blight resistant varieties of lilacs in your garden are suitable.
What Are Some Blight-resistant Varieties Of Lilacs?
Bacterial Blight can become a headache for gardeners, and choosing resistant varieties of lilacs is an excellent way to have happy blooms. Ask the nearest Horticulture institute about which types of lilac are resistant in your locality. Generally, the Japanese Tree lilacs (Syringa reticulate) are disease-resistant.
Lilac Leaves Turning Brown And Dying
First, if you see the lilac leaves turning yellow, brown, and finally falling off and dying, your lilac is most likely suffering from Leaf spot disease. Being a fungal disease, several pathogens cause leaf spot disease. The disease may sometimes cause defoliation due to high humidity around the lilac plant. The leaf spots are usually small and don’t cross over the veins.
How To Prevent And Treat Leaf Spot Disease?
You can follow these tips to prevent or treat leaf spots in lilacs:
- Cut off the affected leaves or part of the shrub and remove the debris to prevent the infection from coming back.
- Cut off the dead branches as a precaution.
- As a preventive measure, spray a fungicide on your lilac during spring. For effective prevention, repeat this once every fortnight during the monsoon season.
Lilac Leaves Curling And Turning Brown
Leafminer damage is the culprit behind lilac leaves curing and turning brown. Leafminer is the larva of a small brown moth that primarily feeds on Privet and Lilac. Leaf debris is where the larvae overwinter, and the pupae overwinter in the curled-up leaves. The larvae cause blotches as it starts feeding on the leaf tissue. Soon, the moths emerge from the pupae and use silk to curl up the leaves around them and then skeletonize them.
How To Treat Leafminers On Lilac?
Controlling leafminer damage is very important as the infestation becomes severe during the fall season and midsummer, and several generations of moths are produced each year.
- Prune the curled-up, mined leaves and remove the debris carefully. This keeps the pest from overwintering in the leaf debris.
- There may be heavier infestations after spring; therefore, control the small populations whenever you spot them.
- Use an insecticide, particularly for leafminers, if the infestation becomes uncontrollable.
Remember to carefully examine and observe the signs as if you see the lilac leaves first curling up and then turning brown; then, the plant is affected by Powdery Mildew.
Lilac Leaves Turn Brown Around The Edges
If the lilac plant is suffering from a lack of water, the leaves start turning brown around the edges. An under-watered leaf has brown edges and curls upwards, so track the watering sessions to understand what problem your lilac is suffering.
When lilacs are young, you should water them once every week, and when they grow older, it is good to water them once every fortnight. Always keep the ground moist up to a depth of 12 inches.
Make sure the ground feels dry before watering to avoid the problems caused by overwatering.
Herbicidal damage can also cause lilac leaves to turn brown around the edges. So, when you apply herbicide, ensure there is no wind and use it correctly. Never apply herbicide on a wet day, as there is no treatment for herbicidal damage; the plant has to revive itself.
Other Reasons For Lilac Leaves To Turn Brown
If you cannot identify lilac leaves turning brown by looking at the signs, then two other reasons may also cause brown leaves.
1. Sunlight exposure
If your plant is exposed to the sun for prolonged periods, the leaves may turn brown due to sun scorch. Look where the plant is and whether it gets direct sunlight for many hours of the day. Use shades to protect the lilacs and prune away the damaged leaves.
2. Herbivores are the culprit
Are there any hungry herbivores visiting your garden and munching away the lilacs? When deer or rabbits eat your plant leaves, the leaves start to turn brown. If such is your case, use a fence around your plants to keep hungry herbivores away, or use repellents.
Tips To Solve The Issue Of Lilac Leaves Turning Brown
- If you see lilac leaves turning brown, then determine the cause and move towards finding the right solution.
- If herbivores attack your lilacs, try fencing around the plant or using repellent to deter the animals.
- If you use insecticides or herbicides that accidentally fall on the leaves, wash them with water to remove any residual chemicals.
- Also, try to use a different chemical next time to keep the leaves green and healthy.
- If a virus infects the leaves, cut off the affected leaves and branches. Also, use a fungicide labeled with the specific virus infesting your plant.
- If the plant is nutrient deficient, then apply a nitrogen-rich fertilizer. Use a different type of fertilizer if the previous one isn’t working, or add some organic matter to the soil to improve its nutrient content.
- Remove the leaves and branches if the plant is affected by fungal disease attacks, and treat the lilacs with a fungicide.
- During winter, if the temperature becomes low, cover your lilacs with a frost blanket if you cannot move them to a warmer location, or make a greenhouse around them to keep them warm.
Frequently Asked Questions About Lilac Leaves Turning Brown
How to save a dying lilac bush?
If your plant is old and doesn’t flower all year, try reviving the blooms by applying a nitrogen-phosphorus-potassium fertilizer with the proportion 5-10-5. The right time to use the fertilizer is once during the fall and once in the spring. Dig two holes close to each lilac plant and fill them with 1 cup of fertilizer.
Why are lilac fronds turning brown after twisting?
Two of the most common reasons for lilac leaf curling are minor insects and some diseases, while there can be a mixture of other factors too. Insufficient moisture or sunlight can also be the reason behind the leaf curling of lilac plants.
What is the right time to trim lilac plants?
It is best to trim lilac a few weeks after the blossoms dim, which is usually the late summer. If you see swarming, cut back some branches to let more air circulate. Good airflow also keeps the lilac plants healthy and prevents lilac leaves from turning brown. As the plants grow old, they need more pruning of the lower branches, closer to the soil, ensuring a better and healthier blooming season for the following year.
Is there a way to prevent bacterial Blight?
If you take proper precautions, you will successfully prevent bacterial Blight. Make sure you choose a disease-resistant variety of lilacs to grow, as it has more chances to stay safe from bacterial Blight. You won’t have to worry about preventing bacterial Blight and other such issues if you plant an impervious variety of lilac.
Wrapping Up
It can be heartbreaking to see the lilac leaves turning brown and the fragrant flowers becoming dull and dead. But if you read through the tips I mentioned, I am sure that you will find out the reason for lilac leaves turning brown. You can then start giving your lilacs extra care and revive their lush green foliage to prepare them for extra blooming this spring.
