Updated: July 2, 2023

Lavender plants are prized for their beautiful flowers and fragrant aroma. However, these plants can be susceptible to nematode infestations, which can cause significant damage if left untreated. Nematodes are microscopic worms that live in the soil and feed on the roots of plants, leading to stunted growth, yellowing leaves, and even plant death. In this article, we will discuss effective methods to get rid of nematodes on lavender plants.

Identify the Problem

Before taking any action, it is important to confirm that your lavender plant is indeed infested with nematodes. The symptoms of nematode infestation include wilting, yellowing leaves, stunted growth, and root damage. To further confirm the presence of nematodes, you can collect a soil sample and send it to a local agricultural extension office for analysis.

Crop Rotation

One of the most effective ways to control nematode populations is through crop rotation. Nematodes are specific to certain plant species, so by rotating lavender with other non-host plants for a period of at least two years, you can help reduce the nematode population in the soil. Some suitable non-host plants for rotation include marigolds, corn, and sunflowers.

Solarization

Solarization is a technique that utilizes the heat from the sun to kill nematodes in the soil. To solarize the soil, follow these steps:

  1. Clear the area around the lavender plant and remove any weeds or debris.
  2. Water the soil thoroughly to ensure moisture penetration.
  3. Cover the area with a clear plastic sheet or tarp, ensuring it is tightly sealed around the edges.
  4. Leave the plastic cover in place for at least 4-6 weeks during the hottest part of summer.
  5. After solarization, remove the plastic cover and allow the soil to cool before planting new lavender or other desired crops.

Biological Control

Introducing beneficial nematodes, such as Steinernema feltiae, can help control the population of harmful nematodes. Beneficial nematodes are parasitic and prey on harmful nematodes, ultimately killing them. You can purchase beneficial nematodes from garden centers or online stores. Follow the instructions provided with the product for application rates and methods.

Soil Amendments

Certain soil amendments can help suppress nematode populations and improve the overall health of lavender plants. These amendments include:

Organic Matter

Adding organic matter, such as compost or well-rotted manure, to the soil can improve its structure and increase beneficial microbial activity. This, in turn, helps create an environment that is less favorable for nematodes.

Neem Cake

Neem cake is a byproduct of neem seed oil extraction and is known for its pesticidal properties. It acts as a natural nematicide and helps control nematode populations in the soil. Mix neem cake into the soil before planting lavender or apply it as a top dressing around established plants.

Mustard Seed Meal

Mustard seed meal is another natural soil amendment that can help control nematodes. It contains compounds called glucosinolates, which break down into toxic compounds when in contact with water. These compounds have nematicidal properties and can reduce nematode populations in the soil. Incorporate mustard seed meal into the soil at least two weeks before planting lavender.

Proper Irrigation

Overwatering can create favorable conditions for nematodes to thrive. To prevent excessive moisture in the soil, avoid watering too frequently and ensure proper drainage. Lavender plants prefer well-draining soil, so consider adding organic matter or perlite to improve drainage if needed.

Conclusion

Nematodes can pose a threat to the health and vitality of lavender plants, but with proper care and proactive measures, it is possible to control and reduce nematode populations. Crop rotation, solarization, biological control, and soil amendments are all effective methods to combat nematodes. By implementing these strategies and maintaining good cultural practices, you can enjoy healthy and thriving lavender plants in your garden.