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6 Ways to Kill Cucumber Beetles, Organically

Cucumber Beetles don’t take long to wipe our your cucumber, pumpkin, squash, and other cucurbit plants. If you don’t get a handle on them quickly they will wreak havoc in your garden. Here are 6 organic methods of pest control to rid your garden of the dreaded cucumber beetle.

how to kill cucumber beetles organically

For three years in a row now, I have lost my cucumber crop to the blasted cucumber beetles. One of my favorite foods to preserve from the garden is my Grandmother’s Secret Dill Pickles, and so the loss of my cucumber crop really breaks my heart. Last year I was able to can a few quarts because some good friends gave me some of their excess cucumbers, but I have not had a good pickle canning session for many years now.

Here's what a cucumber beetle looks like - keep and eye out for these pests! They're cute but they're SO destructive!

Do you see that nasty little yellow and black striped bug on my cucumber plant? They may look all cute and harmless BUT let me tell you, they are real, real pests. They are very destructive.

Sick of cucumber beetle destruction? Here are some organic methods to kill those annoying pests and save your plants.

Besides being able to eat cucurbit leaves in a matter of days, they also cause bacterial wilt which kills the plants. I can live in harmony with many bugs, but not these guys. Killing my cucumbers means war, and I am tired of losing that war!! I’ve tried a few things to kill cucumber beetles over the last few years, but nothing’s been successful. Until this year. This year, I caught them early. And I struck hard and I struck fast.

6 Ways to Kill Cucumber Beetles, Organically

This year, I turned to Diatomaceous Earth. Last year, when I found the dang beetles, I read that food grade Diatomaceous Earth can be used as an organic insecticide, so I ordered a 50 pound bag from Azure Standard. According to the National Pesticide Information Center, Diatomaceous Earth is a type of silica made from the fossilized remains of diatoms. It’s a fine, white powder and it’s edible. Under a microscope, it supposedly looks like shards of glass and it is deadly for any bugs with an exoskeleton, like cucumber beetles, and fleas, and all sorts of nasty parasites. You can read more here at this useful article by Paul Wheaton.

I have read that you should be careful not to inhale DE, but last year when my husband suffered from intestinal parasites, I broke out the DE and made him drink some diluted with water. He also insisted on taking a course of antibiotics, but I have read that DE will do the trick without the antibiotics. So file that tidbit of information away for the next time you get intestinal parasites {or head lice…}.

DE on cucumbers is an effective and totally organic way to kill cucumber beetles.
I tossed some Diatomaceous Earth on my cucumber plants to get rid of those nasty cucumber beetles that kept ruining my crop.

Essentially, the way I killed my cucumber beetles was to dump 100% Food-Grade Diatomaceous Earth all over my cucurbits. I lifted the leaves and doused it good on the underneath since the cucumber beetles like to hang out on the underneath side of the plants. And I covered the dirt all around the plants, too. Because despite having read that cucumber beetles don’t crawl around, I see them crawling all over the ground. So I think they do crawl.The first day I found the cucumber beetles, they were all over. I thought about the situation for a few minutes {because I had to remember WHY I bought that big bag of DE last year…} and headed out to my garden shed. I grabbed the DE and spread it all over using the method I described above.

The next day, I checked on my garden. Instead of finding hundreds of them, I found maybe 10. And I killed them all. The next day, I found ZERO cucumber beetles and I was very encouraged. However, after a few days, 5 maybe, I started finding a few more beetles, so today I covered them all up again with more Diatomaceous Earth since I am going away for 5 days and won’t be able to check on them. It is so helpful to be in the garden every single day to see find stuff like this. I’ve left strict instructions with my husband to be on the lookout for cucumber beetles!

Other organic methods for killing Cucumber Beetles:

  1. NEEM Oil – this is the first thing I tried. I’m guessing that it didn’t work because I was just too late. I didn’t know right away how destructive they were, and by the time I got the NEEM Oil, it was probably too just late. But it is supposed to be effective.
  2. Delay planting – planting your cucumber plants a little later in the season is another way to foil cucumber beetles. If you can wait to plant your cucumbers by a few weeks, you might have luck warding off the blasted beetles. Start them in your home instead and set them out when they are bigger and better able to fight off the beetles.
  3. Row covers – The aren’t that hard to make and they are effective. The one word of caution is that your plants still need to be pollinated so you will have to uncover the rows while the plants are flowering. Learn how to easily cover a raised bed in this post.
  4. Companion plant certain crops can help repel cucumber beetles. Companion planting can be very effective when done correctly. Nasturtiums, onions, and radish are great plants to include in your cucurbit area to help keep the cucumber beetles at bay. For more companion planting ideas, read this post.
  5. Trap crops – some cucurbits are less susceptible to bacterial wilt than others. A good trap crop to plant is the blue hubbard squash. For some reason, cucumber beetles really like this squash and don’t harm it as much as they do other crops.

Cautions I have read about DE –

I read not to use the DE on flowering plants as it also kills the bees that pollinate the plants. A very helpful person on my facebook page told me that I can manually pollinate the plants with a Q-Tip, if need be. One of my plants was already flowering and I am spreading the DE anyway. It does have baby cucumbers on it, so we’ll see what happens.

Otherwise, my garden is growing good. I did find one more bad garden pest on my potatoes, and I will tell you about that soon! But everything else is looking really nice.

My garden is growing well after using some DE to kill the cucumber beetles that kept eating my plants!

Have you ever dealt with cucumber beetles? What did you do? And most importantly, how do you stop them from coming back next year? I am really considering burning my garden this year after it’s done.

Welcome to the HOW TO KILL GARDEN PEST SERIES! 

Who knew gardeners could take such pleasure in murdering annoying garden pests. If you garden, you’ll want to check out on the posts in this HOW TO KILL series. I’m adding new posts to this series each week, so subscribe to my newsletter if you want to know when they’re ready!

This post, though, is all about the Cabbage Worm: how to identify, how to kill, how to prevent. So let’s get on with it!

Valerie Cops

Sunday 23rd of August 2020

After cucumbers coming out my ears for two months cucumber beetles put the skids to production . I have been spraying with water & Dawn every evening & it is helping. Watch my butternuts like a hawk & kill all I can find. Will be burning EVERYTHING from the garden as it is done!

Andrea

Sunday 28th of June 2020

With the nationwide demise of important bees, I can’t fathom how you can advise people to just overlook the fact that their use of DE will further destroy local bees populations. And of course, dead-no bees in your garden means no fruit. Is this really the most thoughtful and educated approach to gardening? Golly.

Tanya Hillard

Tuesday 29th of June 2021

My thoughts exactly!

rovin

Friday 26th of May 2017

you can try salt. 1 liter water and 1/2 teaspoon of salt. then spray it every morning. Salt is also source of nitrogen and its good for plants

Mark

Friday 7th of June 2019

Salt is Sodium Chloride, which has no nitrogen at all. Are you perhaps confusing the chemical symbol Na (sodium) with N (nitrogen)? Most plants have tolerance only to a small amount of salt and overdoing it could easily mess up the carefully balanced pathways of water and nutrients in the root system.

Heather

Thursday 18th of May 2017

What a quick and simple way to get rid of such a destructive insect! Thanks for providing the safety tips for handling DE as well, you definitely don't want to end up hospitalized for making such a simple mistake. Great guide!

Christina

Monday 12th of December 2016

Going from a large number to just around ten is quite the accomplishment. It must have really startled you when you saw the large group for the first time.

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As an Amazon Associate Michelle Marine, SimplifyLiveLove, earns from qualifying purchases.