How to Get Rid of Borers on Lilac Plant

Lilacs are beautiful flowering shrubs that add a touch of elegance to any garden or landscape. However, these plants can become susceptible to borers, which can cause severe damage if left untreated. Borers are beetle larvae that burrow into the stems and trunks of lilac plants, feeding on the inner wood and disrupting the plant’s ability to transport nutrients and water. If you notice wilting, yellowing leaves, or holes in the stems of your lilac plant, it’s likely that you have a borer infestation. Here are some effective methods to get rid of borers and save your lilac plant.

1. Identify the Borer Species

Before taking any action against borers, it is essential to identify the species of borer affecting your lilac plant. Different borer species may require different treatment methods. The most common borer species that attack lilacs include the lilac/ash borer (Podosesia syringae) and the clearwing moth (Synanthedon spp.). These borers have distinct characteristics, such as size, color, and behavior. If you are unsure about the borer species, consult a local horticulturist or entomologist for proper identification.

2. Remove Infested Wood

Once you have identified the infested areas, it’s crucial to remove them to prevent further damage to the lilac plant. Carefully prune out any branches or stems showing signs of borer activity. Cut several inches below the visible damage, ensuring that you remove all affected wood. Dispose of the infested wood away from your garden area to prevent re-infestation.

3. Promote Plant Health

Keeping your lilac plant healthy is essential in preventing borer infestations. A strong and vigorous plant is better equipped to resist attacks from borers. Provide adequate sunlight, water, and nutrients to promote healthy growth. Regularly fertilize your lilac plant with a balanced fertilizer to ensure it receives the necessary nutrients. Mulching around the base of the plant can help retain moisture and prevent weed growth, which can compete with the lilac for nutrients.

4. Apply Insecticides

In severe borer infestations, it may be necessary to use insecticides to control the population. However, it’s important to note that insecticides should be used as a last resort and should be applied according to the manufacturer’s instructions. Always choose an insecticide specifically labeled for borer control on lilac plants.

Systemic insecticides are particularly effective against borers as they are absorbed by the plant and circulated throughout its tissues. This makes them toxic to borers that feed on the plant’s sap. Apply systemic insecticides during early spring or late fall when borers are active. Be sure to follow the recommended dosage and application method provided by the manufacturer.

5. Monitor and Prevent Future Infestations

Regular inspection is crucial in preventing future borer infestations on your lilac plant. Monitor your plant for signs of wilting, yellowing leaves, or new borer holes. Promptly remove any infested wood to prevent the spread of borers.

To further deter borers, you can apply a layer of protective paint or wrap sticky bands around the base of your lilac plant’s trunk. The paint acts as a physical barrier, preventing egg-laying by female borers. Sticky bands trap adult borers as they crawl up the trunk, preventing them from reaching the branches and laying eggs.

6. Consider Natural Predators

Introducing natural predators can also help control borer populations naturally. Birds, such as woodpeckers and nuthatches, are known to feed on borer larvae. Encourage these birds to visit your garden by providing suitable nesting sites and food sources.

Conclusion

Borer infestations can be detrimental to the health and beauty of your lilac plant. By identifying the borer species, removing infested wood, promoting plant health, using insecticides when necessary, monitoring for future infestations, and considering natural predators, you can effectively control borers and save your lilac plant. With proper care and attention, your lilac plant will continue to thrive and provide you with its delightful blooms for years to come.