How to Use Nematodes to Control Black Vine Weevils
- 1). Order the nematodes in time for them to arrive in May or late-August, the best times for controlling black weevil larvae.
- 2). Place the nematodes in the refrigerator until evening when the weather is cool.
- 3). Water the soil in the affected area to moisten the top 3 to 4 inches of soil.
- 4). Open the nematode package and look at the nematodes with a magnifying glass to make sure that they are alive and moving. If not, they were dead upon arrival. Contact your source to order another batch.
- 5). Add the nematodes to water in a hose-end or hand sprayer. The more water you use to distribute the nematodes, the better. Follow any of the package's special instructions for mixing and application amounts. The University of Vermont extension service recommends roughly 1 million nematodes per 100 square feet of soil to be treated (depending on the species and source of nematodes) or 5,000 to 20,000 per pot.
- 6). Spray the nematode water evenly over the soil. Concentrate on the soil around the base of the plants. Limit the amount of water that lands directly on the foliage. Cover an area at least three times the diameter of the plant's foliage.
- 7). Water the soil with another inch of water to wash the nematodes into the soil.
- 8). Keep the top few inches of the soil moist with as-needed watering for 3 weeks after the application.
