Pests - leafhoppers - Ask Extension
Hello. I have a small -medium organic garden in Frederick country. Last year it was overtaken by leafhoppers. I used freshly prepared mels mix with 6...
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Pests - leafhoppers #892304
Asked February 04, 2025, 4:58 PM EST
Hello. I have a small -medium organic garden in Frederick country. Last year it was overtaken by leafhoppers. I used freshly prepared mels mix with 6+ varieties of organic compost to prepare it. In the winter I took some of the soil home to start my seedlings inside and found a lot of leafhoppers appearing and damaging my seedlings. Can you recommend a way to eliminate them from my garden before I start transplanting the seedlings. I have a vertical garden so it's not directly in the ground and I have covers for my planters. I am trying to bypass any harsh pesticide to remain organic. Can I spray the soil before planting to eradicate whats in the soil and top it off with an inch or 2 or fresh compost?
Thank you
Frederick County Maryland
Expert Response
Would you be able to share photos of what you're seeing, both the plant damage and the insects themselves? We suspect they are not leafhoppers, since emerging from soil or potting mix indoors would not be typical, and they are not usually an indoor plant pest. (Is the material garden soil from the ground, or potting mix? The latter is ideal since the former risks bringing in other pests and pathogens that can overwhelm seedlings.) Once we can identify the insects we can recommend how to manage them, both curatively and preventatively.
Miri
Miri
Hello, I don't have many photos as I removed all my plants and restarted with coco coir this time instead of my planters soil. They are definitely green leafhoppers based on pictures I googled and description. They are mostly on the bottom of the leaf and hop or jump when I shake the plant, then land back on it. Tough to catch them as they so quick. They prefer basil, zinnias, flowers mostly. I unable to attached any pictures to the post- it gives me error. I will try again with another post. Thank you
We have some leafhopper prevention tips on the linked web page, but the recommendation to use row cover (or insect mesh netting) to block access to the plants wouldn't be very practical to try on indoor plants, just outdoor garden beds. Their life cycle generally doesn't involve the soil; they may lay eggs in, or take shelter in, plant debris on the soil surface, but they don't burrow into the ground. It's quite unusual for a number of them to emerge indoors and damage indoor-grown plants, especially in winter.
Given their wariness and tendency to evade efforts to squish or catch them, they similarly are not very well-controlled by pesticide use, even with organic options. Anything requiring direct contact to work, like horticultural oil or insecticidal soap, would not be expected to work well. Residual treatments, where residues remain effective for some time, may work, but few are organic. Pyrethrum can be organic and would be the preferred alternative to the oft-used synthetic versions (pyrethroids). Which products using this active ingredient are labeled for indoor use, though, will take some investigating on your part, since we do not have a list.
Getting rid of the soil / potting mix should not be necessary, but now that you have, we highly doubt the problem will recur, at least while the plants are inside. For the growing season outdoors, keeping weeds away from garden beds and covering vulnerable plants with row cover or fine insect netting right after they're planted should keep most leafhoppers and other common pests from causing damage. The unfortunate trade-off with that approach is that any pollinators trying to reach the plants will similarly be denied access.
Miri
Given their wariness and tendency to evade efforts to squish or catch them, they similarly are not very well-controlled by pesticide use, even with organic options. Anything requiring direct contact to work, like horticultural oil or insecticidal soap, would not be expected to work well. Residual treatments, where residues remain effective for some time, may work, but few are organic. Pyrethrum can be organic and would be the preferred alternative to the oft-used synthetic versions (pyrethroids). Which products using this active ingredient are labeled for indoor use, though, will take some investigating on your part, since we do not have a list.
Getting rid of the soil / potting mix should not be necessary, but now that you have, we highly doubt the problem will recur, at least while the plants are inside. For the growing season outdoors, keeping weeds away from garden beds and covering vulnerable plants with row cover or fine insect netting right after they're planted should keep most leafhoppers and other common pests from causing damage. The unfortunate trade-off with that approach is that any pollinators trying to reach the plants will similarly be denied access.
Miri
Thank you!
You're welcome!
