Cucumber beetles, both spotted and striped, are a bane to gardeners all across the country, and as so many of us have had to learn the hard way-they don’t just eat cucumbers. They also enjoy chowing down on corn, squash, pumpkins, melons, and bean plant leaves. But while their munching is frustrating for the gardener, and definitely not the best thing for the plant, it’s also not the biggest risk these pests pose to a harvest.
Some experts estimate that cucumber beetles could eat up to 25 percent of foliage without reducing the plant’s fruit production. In reality, the worst problem with cucumber beetles is the fact that they carry and transmit bacterial wilt disease, a literal killer for susceptible young plants.
For this reason, many of the following strategies focus on delaying the almost inevitable contact between plant and beetle. If your plants can grow a while without being exposed to the disease, they stand a much better chance at staying healthy and productive. Of course, we also include some tips for managing the beetles once they do bed down on your lovely cucurbits.
13 Ways to Prevent Cucumber Beetles
1. Till in Late Fall
Don’t wait for spring to do all of your tilling. When it begins to get cold, but before the ground freezes, till up your garden. This strategy will reduce next year’s cucumber beetle population by exposing the beetles that have burrowed underground for winter to the harsh cold they were trying to avoid.
2. Rotate Crops
This is particularly applicable for people with larger gardens or multiple garden locations. Switching the location of your cucurbits from year to year will force the cucumber beetles from the previous season to make a trek if they want their favorite food. It’s especially effective if there are obstacles in between the old location and new location, such as shrubs or plants they won’t eat. (Here is a helpful list of shrubs.) This technique can buy your seedlings some time before you expose them to disease and chomping, protecting them during their most vulnerable, young stage.
3. Use Transplants
You can take that logic even further and use transplants instead of sowing seeds directly in the ground. Again, seedlings are very vulnerable to the bacterial wilt disease that cucumber beetles can carry. Once they contract the disease, not much can be done to save them. That’s why it might be best to avoid exposure altogether and sow your seeds in a greenhouse or on an elevated surface. Transfer them to the ground when they’re a little bigger and more capable of withstanding some damage.
4. Plant Late
Consider giving the beetles the ol’ fake out and wait a little longer to plant your cucurbits. With any luck, the beetles from the previous season will assume they need to move on from your garden if they want to find any food. This works well in tandem with the transplant method.
5. Choose Resistant Varieties
Try opting for plant varieties that cucumber beetles don’t like as much or varieties that are less prone to contracting wilt disease. You can find suggestions here at .
6. Use Row Covers
If you do choose to plant seeds directly in the ground, consider using row covers until your plants begin to bloom. Be sure the soil comes a little past the seal so no grown beetles can get in. Once you see the first bloom, remove the covers or they will inhibit proper pollination.
7. Plant Trap Crops
Because cucumber beetles tend to congregate around the perimeters of gardens (as opposed to congregating in the middle), it might be worth your while to plant some diversion crops around the edges of your vegetation operation. You’ll still want to control the population, but they should be easier for you to access and manage before they move inward toward the plants you’ve grown for your own use and consumption.
8. Lay Down Straw or Organic Mulch
Straw mulch (without any weed seeds!) can help with your cucumber beetle problem by providing shelter to their natural predators-wolf spiders. It will also house other nonpest food for the spiders, such as springtails. Organic mulch works similarly, but at the microscopic level-it encourages a more diverse population of microorganisms in the soil, which can help plants fight insects naturally.
9. Shake or Knock Them Off
One super simple method to deal with adult cucumber beetles is to gently shake or knock them straight into a solution of water and detergent, or salt water. And they need not die in vain-you can compost the captured critters!
10. Use Yellow Sticky Traps
Another simple way to reduce the population of cucumber beetles in your garden is to use yellow sticky traps. Like so many other insects, cucumber beetles can hardly resist the bright color-once they’re stuck, it’s easy to remove them without the use of chemical pesticides. While there are plenty of commercial options available, it’s also easy and economical to make your own pest sticky trap. But fair warning: These traps are also effective at capturing beneficial insects, so they may not fit into your overall strategy.
11. Remove Them Manually
Cucumber beetles can be difficult to catch with your hands alone, but slap on a pair of yellow gloves, rub them with Vaseline, and you’re in business. This method and a few others that involve physically removing the beetles from your the plants are best implemented in the early morning because the insects tend to move more slowly in cooler temperatures.
12. Introduce Natural Predators and Pathogens
Call in some reinforcements, and let them do your dirty work for you. Wolf spiders and ground beetles both feed on the pest in question. What’s more is that even if the wolf spiders don’t feel like eating the cucumber beetles for some reason, their simple presence will have the cucumber beetles avoiding the area and feeding less. Additionally, fungal pathogens and nematodes are widely available biopesticides that can reduce rootworm (cucumber beetle larvae) activity.
13. Suck Them Up With a Vacuum
That’s right, your handheld vacuum isn’t just for couch cushions and car seats-you can also use it to remove pests from your plants before they do too much damage. Just be sure to empty the bag away from the garden so surviving beetles don’t head back in for round two.
With spring rapidly approaching, we hope you’ll make use of some of these precautions and pointers. Cucumber beetles are a nuisance, but with a little thought and effort, you can reduce their impact and enjoy a productive growing season.
Ruth Gulley is a native Texan who now resides in Virginia where she enjoys homeschooling her stepson, cuddling with her clumsy cat named Bird, and watching seasons one through four of The Office on repeat.
Want to learn more about how to prevent and control cucumber beetles?
The Old Farmer’s Almanac covers Cucumber Beetles
Extension covers Managing Cucumber Beetles in Organic Farming Systems
Vegetable Gardener covers Controlling Cucumber Beetles
Very valuable gardening advice