Here are tips on how to identify, control, and get rid of the squash vine borer.
What are Squash Vine Borers?
It can be so disappointing when your squash is thriving and suddenly starts to wilt. The culprit is probably the squash vine borer. The plants wilt because larvae is boring within the lower part of the stems.
Squash vine borers attack squash, zucchini, pumpkins, and gourds. They prefer Hubbard squash and are not as fond of butternut squash. Cucumbers and melons are not usually an issue.
The borers overwinter in soil as pupae in cocoons. When the adult clearwing moths emerge in early to midsummer, they lay eggs singly or in small groups at the base of stems. The eggs will hatch within 1 to 2 weeks after being laid. The larvae will then bore into stems to feed for about 2 to 4 weeks; sometimes they may also bore into the fruit. In northern areas, there is one generation per year; in southern areas, there may be 2 generations.
If caught early, it’s possible to save the plant. If caught after the eggs hatch, it may be too late. Controlling the squash vine borer is mainly about prevention.
Reader Comments
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Vine Borer Madness
I've been gardening in Connecticut for over 40 years and for the last 20, the vine borers are a yearly battle. I have tried every method of prevention and treatment mentioned in this article and all the replies, but those dang worms win! This year I tried the "bait crop" method. Plant squash, wait until you see signs of vine Borer damage, i.e frass and/or sudden wilted leaves and then dig the entire plant out, getting some of the dirt around the roots and either immediately burn it, or put the affected plants in a heavy duty trash bag and tie it tightly at the top. The concept is that the borers will be eliminated in the larva stage and the life cycle is broken. Since we had snow and freezing temps into late April this year, I had to start my bait crop inside. I planted the seedlings (yellow crookneck squash) out the 3rd week of May and on June 15th I found frass at the base of several stems. Dug the plants out and before they got tossed into my fire pit, I did some investigating and slit open the stems from several plants. I was not prepared for the sheer number of borers each plant contained. My biggest plant, contained 56, yes 56 individual borers ranging from just barely visible in size to well over an inch. Every stem had borers, even those showing no signs of frass or wilting so apparently they enter in numbers through one hole then spread out into the various stems. Not only were they near the frass, but throughout the hollow stems and I even found some when I split open the thick veins on the underside of the leaves. No wonder my prevention methods didn't work, once hatched, these borers go into every root, stem and leaf vein the plant has..After carefully dissecting the first 5 plants, taking care to kill every Borer found, all the plants went into my fire pit. I planted a second crop, in a location I never grew squash before. The plants are just big enough to have blossoms now. I have been carefully watching for the moths and doing the best I can to inspect for eggs and of course it happened again..... Today there were wilted leaves so I slit the stems down to the soil level and sure enough, Borer larva , the*&@#!!!!! things!
So despite planting a sacrificial crop early in the year, burning the entire crop once larva were found, the second crop planted at least 100 feet from the first, and planted where squash had never been grown before, the 2nd crop got attacked by the same thing. This also confirms that the cold North East states get 2 hatches per year.. So despite my longing for home grown organic yellow squash, crop #2 went into the fire pit today. I'm going to plant a 3rd crop and hope our fall is mild enough that I get squash.
By the way, I've spent time every day looking for the moths and never seen a single one, so these pests are very hard to prevent and control. Not sure what I'll try next, but I refuse to use chemicals and I refuse to give up!
Squash Borers
Dear Lisa,
Your experience with the vine borers has to be most discouraging. I have been gardening for over 50 years but usually have not grown squash. Many years ago I had some excellent results with zucchini w/o any problems. So this summer (2018) decided to try Acorn squash. The plants were most robust and healthy but the next day they were totally wilted and dead as if something cut them off at the root.
After reading your impossible to win war against the borer and how the larva can winter over in the soil and how you tried to remove the borer by burning all the infected plants causes me to think why not burn the soil in which you are planting the vines.
Of course I realize you cannot burn an entire garden of say 30' x 40' (that is size of my garden). However, if you grow the squash in raised beds of say 4' x 4' (as I am also doing) or in large half barrels the amount of soil burning would be contained to a small area.
Start with a large gas (not gasoline) burner. Do the immediate soil surface first. Then turn over about 3 to 5 inches of soil and repeat the process. Do this about four or five times. This might burn (kill) all the larva in the soil.
You probably have been in contact with your local state agriculture office for info. If not check in with them.
Also saw a suggestion of placing diatomaceous earth around the immediate area the squash plants. In case you don't know diatomaceous earth is a very fine powder composed of the shells left by tiny marine creatures. It is often used in filters, especially swimming pool filters. The powder is so fine that it gets into the breathing system of insects cause irritation and subsequent death. In other words they seem to choke to death.
squash borers
I've been told that planting nasturtiums and garlic in your garden will deter the squash bugs. I will give it a try this year. They get my zucchini every year before I do.
No on the garlic
My garlic was right by my zucchini and cucumbers, onions too. I will try nasturtiums.
Worse year ever for these disgusting things
I have been gardening for over 30 years and never ever had a bad zucchini crop. Well, I finally met the squash borer and boy did they go to town on my squash. First limiting the plants growth but I got one zucchini until I decided to look inside the stalk. I found one that was over an inch long and he feasted on inches of the stalk. Well I got so mad I pulled up all my plants and dug up the soil and found babies, look like little white worms and burned them with a blow torch. Also found tons of ants protecting their eggs and of course aphid eggs on the roots of my zucchini. The Northeast is getting a lot of heavy rain and I do believe this is the culprit also my friend leaving rotting and old plants in the garden from last year wasn't a good idea (no more of that). I also lost my cucumbers, honeydew melon and cantaloupe, so they do go after cucumbers. I have read a few articles and found the foil around the stem, but also using a rhubarb leave as a cover for the seedling (yes I am starting over) and will try this method too. We also got nematodes hoping they will kill the little ones as how can they get to the big ones in the stalk? We have Sevin too and will treat the soil with this as the little ones are the ones I am worried about now with the new seedlings I have. I like the picture of the moth, I thought it was just a regular white moth but now I know what to look for. The other comment from that man just didn't see the picture? Also there is a rhubarb tea that is poisonous that I will try in the soil. I will try anything now before the season is over, but next year I plan on turning the soil over, getting millions of nematodes not before I burn some wood right in the garden to add some wood ash to it and hopefully burn the little babies before they go hide for the winter. I will not let these little bas***ds ruin my garden. My advice is don't give up, get determined as home grown veggies vs. grocery store is well worth all the work and frustration. Don't let any pest ruin your fruit and veggies. Get a blow torch and burn them all, lol...
borer
Interesting Gloria, I live in the North East, Pennsylvania and lost my Zucchini and Gourd plants. What a disappointment. It happened so fast.
squash borers
We have lost several plants in years past to the dang borers!! Not anymore:) My husband is vigilant with his little shaker can of Sevin dust.
If it gets watered or washed away by rain, here he goes and sprinkles more. He keeps a little fine dusting around the stems (and up on the stems) of all our plants. NO borers. I am not usually so agreeable to using chemicals (in this case carbaryl 5%). But, we have tried everything else. This really works.
Hopeless
I did the manual "surgery" to remove the borers one year, and it was probably the most disgusting job I've ever had to do for my garden. Those worms wreaked havoc on my garden and even after painstakingly removing them they still kept coming back. I don't have the room to plant trap crops, nor do I feel they work as they just encourage more breeding of the bad insect.
This year I'm seeing the moths but I have no practical way of preventing them from laying eggs. Going to do what I did last time and use a systemic pesticide that both kills the borers and degrades into harmless compounds before harvest.
Try the Yellow Sticky Traps
I just found these on the web after hearing about them. The moth will fly onto the sticky side and get trapped. Also good for aphids and whiteflies. I just ordered some tonight and hopefully they will work. It said it attracts moths so I'm willing to give them a try. You can't give up.
squash vine borers
This is the second year I have had to deal with these monsters. This year I have been diligent picking the eggs off all my plants, (very time consuming) but yesterday I found 2 plants with evidence of the borers and had to pull the borers out - so I obviously missed at least 2, but probably more eggs. From my observations the moth lays the eggs on the top areas of the plant, I have found eggs on the tops and bottom of leaves, on the curly strings that catch the trellis netting, the leaf stems, bases of the flowers, and the plant stems, all mostly on the upper parts of the plants. Its extremely frustrating and heartbreaking to see the plants die after so much effort to protect them. In my search for a solution I did come across some netting for moths/butterflies - similar to deer netting in price and material, but it is NOT sold in the USA, at least not in a cost effective way. The UK and Europe sells the 'butterfly netting' for a similar price as deer netting $70/roll 7'x100'. Some companies here make something similar, but the price is triple or more; and to have it shipped from outside the US raises the price too high. This is the second time I have found solutions outside of this country that are available to other country's consumers - I can only think it has something to do with the chemical companies not wanting us to have organic options....very frustrated!!
Squash Vine Borers
Hi Vicki,
It sounds like you’re putting in a lot of effort into protecting your garden, and that’s unfortunate the butterfly netting is too expensive. Try going out with a butterfly catching net, or tennis or badminton racket in the evening. If you see any of the moths near or on your plants, capture and dispatch of them before they can lay the eggs. Each can lay over 150 eggs in its lifecycle, so stopping even one before it lays will do a lot of good. Also, next season try growing a more resistant variety of squash called Cucurbita maxima, which grows supplemental roots from its vines as it grows outward, allowing it to still produce squash even if the main stem were to die.
SVB
I know this is a year old so you may have come to some resolution by now, but I thought I would comment anyhow. I thought your comment was very observant. I live in north Texas and I have dealt with SVB for 4 years now. It is definitely a formidable pest for a home gardener. I grow organically and have tried all of the methods recommended by supposed agricultural specialists and internet advisers such as wrapping the base of the stem, manual removal of the larva by “surgical cutting”, hand picking the eggs, injecting BT into the stem, stringing a wire to impale larva, and row covering. Of all these methods, the only successful method by any means at all was row covering. Every other method fails for their respective reasons. Aside from row covering, planting early may be an option that would allow at lease some harvest before the arrival of the borer. I have done that before with a few zucchini coming off the vine before infestation, but in Texas, you have a much shorter time before temperatures warm up and the SVB arrives. Other than that, I have learned to grow varieties of cucumbers that they leave be. I am unable to grow pumpkins or winter squashes, gourds or anything of the sort. I do think there is some truth to what you say about some places making organic methods less pragmatic. Good luck to you in your garden.
What resistant varieties do you grow
What varieties do you grow that are more resistant?? Thanks! Kate
SVB
I'm in North Texas as well. Just realized all my acorn squash and pumpkins are goners. Sad. Thanks for sharing your experience.
inexpensive netting
I checked out my local craft store and toille is a very fine netting used mostly in wedding and party decorations. It costs only $1.25 a yard.
Squash borer.
According to the old farmer's almanac, what stage should we apply wood ashes and how do we apply it?
Wood Ash Ph
Yes, wood ash can affect soil Ph, sometimes for the better, sometimes not. It all depends on your soil so it is best to have it tested to determine if applying wood ash would be beneficial or harmful. We will try to get a pic up, but it is difficult to find any that are of the necessary size and quality. The eggs are tiny, flat, oval, and brown.
squash borer worms
I appreciated all the information and the way it was presented - both organic and inorganic.
Many options available. Next year I will try new soil (am a container gardener), laying down wood ash at the stem's base (anyone tried this yet since 1963? If so, what are the results?) wrapping vines with foil, hilling soil, then more wood ash. How will the addition of wood ash affect the ph of the soil? Any amendments to counter it necessary?
Thanks.
If possible - could you add a photograph of the eggs laid at the stems?
I believe you meant " try
I believe you meant " try growing a squash that’s *more* resistant such as Cucuzzi" (not less) :)
Thanks for this article! Very helpful!
Resistant Squash
Oops, thanks for catching that, Hannah! We really appreciate it, and we’re glad you’ve found the article helpful!
successful and easy control of squash vine borrers
I have looked over many sites dealing with Controls for squash Vine borer. With a heavy infestation of these moths I have fought to protect squash using nearly all the suggested methods. Some work(complete netting of the plants) but are very labor intensive. Finally I watched the moths in the garden for many hours (letting them do their nasty work without disturbing them) and realized that they are extremely sensitive and careful when laying (THIS IS THE KEY TO CONTROL!!!!!). I then developed a much Less labor intensive method that seems to work Exceptionally well. Chopping hay in 2 to 4 inch lengths I let the hay lightly fall over the stalks, particularly the base, and even onto fruit to form a very open matrix. The moths will not land and lay, it appears to prevent landing of the moths. It's possible to walk through the garden and drop fluffy handfuls of chopped hay over any exposed vines every few days quickly and efficiently, apparently completely discouraging the egg laying. This is an organic method(Obviously) and takes relatively little time in a small home garden. If this approach is used Diligently it is nearly 100% effective. Anyone using the technique needs to make just a matrix of hay, Very open and loose, LIGHTLY ALLOWED TO DROP OPENLY, A HAND FULL AT A TIME (no need to put a lot) but with small enough gaps so that the moth is discouraged. The moths DO NOT LIKE CLOSED AREAS, THEY WANT OPEN ACCESS TO STALKS AND FRUIT - AGAIN, THIS ISTHE KEY). You don't have to pack in the chopped straw, just scatter it with most pieces looking like open "pick up sticks", that seems to be all that's needed. If you experiment with this method you will find it EXTREMELY effective and efficient. I've tried to spread the word on many garden sites but have not been successful, please share the idea. Call it the Mayo technique!
I am trying "The Mayo
I am trying "The Mayo Technique" next year on my pumpkin vines! These stinking pests are a real problem in WV, and after many approaches to deter them, my pumpkins are a complete loss this summer...just ripped my vines out and bagged 'em up. Grrrrr. I used to grow 100 lbs pumkins in NE Ohio with no sign of them. Here's hoping it will help me to grow that one big pumpkin I'm dreaming of for my little girl! Thanks for the tip! :)
The Mayo Technique
I am really excited to try this. It has been too long since I've had a home grown squash!! Is it possible to post a pic of your protected plants? This sounds really interesting!
Mayo Technique
Can you post a photo of this?
Squash Vine Borer, the Garden Pest from Hell
Squash Vine Borer, the Garden Pest from Hell
The Squash vine borer is the hardest pest to control in my garden. Excuse my seeming cynicism in these comments, because I am a little, No, a lot frustrated with failure year after year and the lack of effective methods and frankly some silly advice in much of the literature. These little worms have got our number. We can go to the Moon, and that was 45 years ago, and cure many cancers now but we cannot solve the borer problem. I have no agenda against the writer(s) of this article and sincerely hope whoever it is will not take my views personal. I am sure they are professional writer(s) and above any pettiness that might come from a disrespect of my views. The contents here include most all the common points found in the literature universe I am aware of. If the writer(s) do take issue you may never see this article or they might retaliate by correcting my spelling or grammar. If so, I have had it. They can only give you the material available. The best advice any have given up to now on this subject is of limited value if not total crap. If not clear by now, I have attempted to inject a little humor in what I say. If that is not obvious then I suck at something besides fighting vine borers.
This article is somewhat helpful but all stuff I have heard before. Reading this article, I noticed there are no photos of the eggs and little information on how to read the signs of their presence before the eggs get laid? Timing is going to vary by your climate and latitude. Being able to act early and knowing what to do is critical. This article could not be more correct on that point. They are spot on. So what er ya gonna do? Sounds like you best be doing the whole list, all the way up to everything short of making a moth voodoo doll. Will you have time to run the rest of your garden? Will you engage in an focused and intense battle with the borers only notice later it has been two weeks and everything else died form neglect.
No photo of the moth here either. I thought moths were those butterfly looking things that fly around the porch light in the summer. These things look more like a wasp. I have seen them before and I found it a moment of helpless feelings that either he/she or one of its nearby cousins has a plan to cause loss of my squash and anything else they might fancy. Trying to catch or trap the moth? Good luck with that one. I am sure you will get one here or there with the right trap. Stand around the plants at dusk and dawn and catch them lighting on the plants and kill them. How? A fly swatter or dish towel pop? Does LOL fit here? All it takes it one moth to lay eggs on every plant you have, unless you have a commercial crop then it might take two or three. Photos? I really think they would be helpful so you know what to look for so you know they are here/there…you know? You still might fail to stop them but you are not blindsided. Plant two crops, one early and another later, which is intended to be one for the worms and one for you? Ridiculous! Don't plant where the moth eggs might be in the ground. Hmm? The moth can fly, so zipping over to another spot in the garden a few feet away is not going to trouble him. Netting? Will work for the birds maybe. For the Moths? That is sort of goofy. It might serve to keep the worm in. These moths are tiny and can easily get around if not through netting. Netting with holes that small might impact vital sunlight the plant requires. Just one moth finding its way past the netting and oh well, you are in for it again. So, more than likely, netting is not a very effective method to stop them. My frustration, and I expect yours as well, is that all you get are these measures to take; that in aggregate, do not stop the problem. No pun intended but there are holes in about everything suggested. Maybe it slows them down a bit but what do you profit by taking all the measures when one moth in one day can lay enough eggs to destroy your crop. Even you mange to take out the locals there is a chance an outside hit-moth from the next door garden with show up. And, you if don't see the eggs in time, inside two weeks they have moved in and started on the buffet. Even if you see the eggs before they hatch, how do you get them off other than cut a hunk out of the stalk? What happens if you drop a few in the process? I wonder.
Once you see the hole and the frass/droppings they are in the stalk and the only hope you have is injecting Dipel BT liquid inside the stalk but it is hard to tell where to inject with your syringe. Plus it is hard to get to the base without breaking the plant. Unless careful, you will do more damage than the worms. slit the stalk, remove the worm and cover the cut with soil. Good for the one worm. What about the rest of the family further up? What about the idea of sticking a wire in the holes to attempt to skewer them? Samurai Gardner, Hieah! Well that might work sometimes. Often there are three and four of the worms in one plant and they are constantly moving. So bag one and the others to still get the job done. Once inside the stalk they will flatten the plant in a matter of days. Last year I started slitting one plant and by the time I finished the plant was shredded with cuts because you have to start at the hole and keep cutting until you find the little jerk. I would say giving one of these worms one day on your plant is enough to wilt it severely. There is really no one single best solution and I find that discouraging. The only absolute way to stop them is to not plant squash.
This year I have planted squash and again, I will do battle with these ugly little slim bags for the freedom to have squash on the table. Sadistic really but I want squash. I refuse to let a worm dictate my dietary choices. My plan, while not perfect, is to spray, spray, spray. I plan to mix liquid seven and Malathion a little stronger than recommended and spray the stalks from the ground up to as much as a foot and the ground around it 6-8 inches. Do not spray blooms is good advice offer in this article. Why spray the ground? I don't know. It makes me feel better. If the worm gets a taste of the poison and makes a run for it maybe he won't get far. I will spray once a week. More if it rains. I may try wrapping the stalk with foil but suspect that it will be hard to apply enough to cover everywhere they might lay eggs. Plus the moth could get behind foil enough to give the eggs a barrier from the poison. I may try foil anyway because it is reasonable prevention. I will watch for the holes in the stalk and inject BT into infested plants. I fully expect I will have some get in but hope I can have them check out early. I will inject high and plentiful until I see it running out of the entry hole.
After all of that is done, or maybe better if before, pray the poison spray works.
Billy Knight
05/17/2016
Worms
I couldn't agree more. My entire crop was decimated last year. This year it will be spray and dust, dust and spray sevin.
research
I realize the original post is over a year but you raise a point I would like to address. The reason we can go to the moon and treat many cancers is because of research dollars. I've seen many an opinion piece by irate individuals because government agencies had the nerve to give a researcher $100K to study the reproductive cycle or life span of some stupid, useless bug. I've done research and it takes a lot of time and a lot of money. Then when you finish that study you need to study if the remedy is harmful to humans, pollinators or species that prey on other pests. Again more time and money. The sad truth is the population does not support scientific research unless it is the big picture and/or they can see an immediate and obvious benefit for humans.
My solution for Vine borers and Squash bugs
I have been gardening since I was 22 and I am now 59, never have I seen this problem like this before. Last year was the worst yet so far. My friend slit the stem and found two huge ones. I on the other hand have no patience and just uprooted and started over again. I did read if you take a rhubarb leaf and wrap it around the base of the plant, well that worked but I also think it worked because I killed most of the ones in my garden already. But I got some zucchini, not much but I did. No cucumbers at all. How did I kill them, eggs too, your going to think I'm nuts but I got a propane torch used for plumbing. I go out there and if I find anything that resembles a stink bug, wasp, even ants I burn the suckers. Eggs that are on the back of a leaf I break it off and burn the eggs. My neighbor and I bought nematodes about 30 million of them and let them loose, we couldn't really tell if it worked, not really with the gnats. The gnats and the vine borers killed my honeydew melon and they were beautifully plants. So, this year, we have many gnat traps, more nematodes, will try again the rhubarb leaves and the foil and I have some netting too when the seedlings are young. I will always use my trusty propane torch to burn beetles, June bugs, ants, leaf hoppers, you name it. The ants actually run from me anymore, lol... I light the torch as soon as I get into the garden early in the morning and I have burned a few while they were sitting on a leaf. They can't lay eggs if they are fried, they can't fly. I then pick them up and put them in the garbage and that's it. Oh, and this year we are tilling the garden. My neighbor likes to leave old dead plants from last year in the garden, but we got rid of them. No more big flat rocks or boards either. Don't know what happened that these bugs are just out of control and where did they come from. We need to have an immigration law against this bugs from hell, our food is at risk.
I started my pumpkins in the
I started my pumpkins in the greenhouse until July 14th. Thought I was safe here in south Jersey. But no, I just caught two moths today, August 5th. Obviously, we have a second hatch here. Yuk....
I'm from Central NJ and
I'm from Central NJ and planted yellow crookneck squash in mid-July. I saw three adult squash borer moths on the plant in late July (managed to kill one). Today, I saw evidence that squash voter beetles have been damaging my squash plants. I pulled one out so far and am debating what to do with the other one. My garden has been a disaster this year, from downy mildew to wilt to being overrun with cucumber beetles to something killing all my pepper plants and now this. It is enough to make me think about giving up.
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