Updated: July 23, 2023

Nematodes can be a significant problem for Monarda plants, also known as bee balm or bergamot. These microscopic roundworms can cause damage to the roots of the plant, leading to stunted growth, yellowing leaves, and overall poor health. Luckily, there are several methods you can employ to control nematode populations and keep your Monarda plants thriving. In this article, we will explore some of the most effective strategies for getting rid of nematodes on Monarda plants.

Understanding Nematodes

Before we delve into the solutions for nematode control, it is important to understand these pests and their life cycle. Nematodes are tiny, unsegmented worms that live in the soil. There are both beneficial and harmful nematodes. Harmful nematodes, such as root-knot nematodes and lesion nematodes, feed on the roots of plants and can cause considerable damage.

Nematodes have a complex life cycle, which includes both free-living and parasitic stages. They reproduce quickly, with females laying hundreds of eggs at a time. These eggs hatch into juveniles that continue to feed on plant roots, perpetuating the cycle of damage.

Cultural Practices

Implementing cultural practices is an essential first step in controlling nematode populations. Here are some practices that can help reduce nematode infestations on Monarda plants:

  1. Crop Rotation: Rotate your Monarda plants with non-host crops every few years. Nematodes often have specific host plants they prefer, so by rotating crops, you disrupt their life cycle and reduce their numbers.

  2. Soil Solarization: This technique involves covering the soil with clear plastic during hot summer months to trap heat and raise soil temperatures to lethal levels for nematodes. It is effective in killing nematodes, weed seeds, and other soilborne pests. Before solarizing, make sure to remove any plant debris and water the soil thoroughly.

  3. Sanitation: Remove and destroy any infected plants or plant parts to prevent the spread of nematodes. Regularly clean gardening tools and equipment to avoid transferring nematodes from one area to another.

  4. Good Drainage: Nematodes thrive in moist conditions, so ensuring proper drainage is crucial. Improve soil structure by adding organic matter, such as compost or well-rotted manure, to enhance drainage and discourage nematode reproduction.

Biological Controls

Introducing beneficial organisms that feed on nematodes can be an effective biological control method. These organisms act as natural predators, reducing nematode populations in the soil. Here are a few biological controls to consider:

  1. Nematode-destroying Fungi: Certain fungi, such as Paecilomyces lilacinus, are known to parasitize and kill nematodes. These fungi can be applied as a soil drench or incorporated into potting mixes before planting Monarda plants.

  2. Nematode-resistant Plants: Some plant varieties have developed natural resistance to nematodes. Research and select Monarda cultivars with nematode resistance to decrease their susceptibility.

  3. Beneficial Nematodes: Certain species of beneficial nematodes, such as Steinernema carpocapsae and Heterorhabditis bacteriophora, actively seek out and kill harmful nematodes. These beneficial nematodes can be purchased from garden supply stores and applied to the soil according to package instructions.

Chemical Controls

Chemical controls should be considered as a last resort when other methods fail to effectively control nematode populations. Nematicides are chemical compounds specifically designed to kill nematodes. However, they can also harm beneficial organisms and have potential environmental impacts. If you decide to use a nematicide, it is crucial to carefully follow the instructions provided by the manufacturer and take appropriate safety precautions.

Conclusion

Nematodes can pose a serious threat to the health and productivity of Monarda plants. Implementing cultural practices, such as crop rotation and soil solarization, is essential for reducing nematode populations. Additionally, biological controls, like nematode-destroying fungi and beneficial nematodes, can help keep nematode numbers in check. Chemical controls should only be used as a last resort. By combining these strategies and implementing good gardening practices, you can effectively get rid of nematodes on your Monarda plants and ensure their long-term health and vitality.