top of page
  • Writer's picturerebeccaecarpenter

Troubleshooting: Squash Vine Borers

Last summer my squash plants died a slow and painful death.  After months of tilling, sowing, watering, composting, and lovingly tending to the plants, we were only able to harvest one sad little squash before the plants died.  I had no idea what was happening to them, and I felt helpless and frustrated watching them die.  So I did some research and found out about squash vine borers— a worm that eats its way through the inside of the plant, effectively cutting off its supply of water & nutrients, and thus killing it.  When I conducted an autopsy on our squash plants, I discovered that we did indeed have borers in our vines, but by that point it was too late to save them.

So this summer I was prepared for the borers, and determined not to let them get to our squash crops.  I began taking precautionary measures early in the season:  I wrapped the bases of my vines with tinfoil, I sprayed the vines with neem oil (an organic substance that repels some pests), and I made little yellow traps and put them around the base of the plants.  I also inspected the plants every morning, searching for the tiny eggs and removing them with masking tape.  I even chased the adult egg-laying moths around like a lunatic with a butterfly net (though I never did catch one).

[this is not what it was like]

Late June and early July is when the borers are actively working to get into the plants — the adult moths lay their eggs on the vine, the eggs hatch, and the larvae burrow into the squash vine and start chowing down.  So I’ve been on high alert for the past few weeks, and I figured that my vigilance had gotten us through the borer gauntlet, and that our plants would be safe for the rest of the season.  I’ve been regularly checking the plants for frass*, and everything has been looking good.  (*Frass is a gloppy orange-ish mass — kind of like wet sawdust — that is excreted from the larvae as it eats its way through the vine.  The presence of frass on the outside of the vine is the only way you can know a borer is inside.  Other than a dead squash plant, of course, which is a pretty good clue.)  So yesterday I was out checking the plants as I do every morning.  Tomatoes, good.   Peppers, good.  Beans, good.  Squash, goo… WHAT?!?!  Oh please do not let that be what I think it is.  Closer inspection, eyes squinting.  Yes, for the love of Pete it is what I think it is.  Frass.  I let out a string of expletives that I’m sure my neighbors really appreciated.  My son came running to see if I was ok, and I had to tell him I was just really mad about a worm.  He gave me a curious look, because I’ve always taught him how beneficial worms are for our gardens.  So I explained about the borers (not technically a worm), and he nodded his understanding and then suggested I take a few deep breaths.  Sage advice from an 11 year old. So after the deep breaths, I faced what I knew I needed to do:  plant surgery.  Once a borer is in the vine, there’s only one way to save the plant — you have to slice open the stem, find the larva (it’s white and squishy and looks like a grub), remove it, and destroy it.  Otherwise the plants will most definitely die. One thing that’s useful to know about me before we continue:  There is only one thing I hate about gardening, and it’s bugs.  I don’t like them near me — or God-forbid ON me — and I definitely don’t proactively try to touch them.  So digging into a plant in search of a squishy white bug is WAY out of my comfort zone.  But I knew this was necessary because my love for squash outweighs my dislike of bugs.  Squash is my all-time-favorite vegetable, so this bug seek-and-destroy mission, although mortifying, had to be done.   And so I gathered my courage, put on my gloves, grabbed a knife, and dove in.  Here’s how it went:

At first glance, the squash plants look great — strong stems, healthy leaves, lots of fruit growing.

But upon closer inspection of this first plant, I see the tell-tale sign of borers inside — frass.  You can see the yellowish globs of larvae excrement (frass) on the base of the vine, where it looks a bit chewed-up.  This means there’s a critter inside chowing down, which will soon kill the plant.

So I check the other squash plants, and sure enough, there’s another one with frass…

… and another one.  This critter even got in under the tinfoil I had wrapped around the base of the vine as a precautionary measure.  Wily ones.

So I do the only thing that can be done to save the plants — I have to cut open the stems, find the borers, and remove them.  Let’s just say that stabbing squishy squirmy grubs with a knife is not my most favorite way to start my mornings.  Deep breaths.

And here we go.  First slice made, and boom — out comes this squirmy little guy.  I really don’t like to kill anything — even the smallest insect — but this is necessary to save the plants.  This is NASTY business!   Deep breaths. 

Aaand, here he comes.  Oh why did I decide that growing our own food was a good idea?  

One down, many more to go.  Plant #2 is small and frail, so I pull the whole thing out of the ground, knowing it isn’t worth trying to save it.  I slice it open, and the fattest, blobbiest grub comes squirming out.  For the love of all things holy. 

You have GOT to be kidding me.  He’s bigger than the vine itself!  More obscenities.  Time to step away.  More deep breaths.  I can’t believe I’m doing this.  And no one is here to witness it, so I’m not even getting any credit for it.

Ok, surgery finally complete.  [I am spent.  And in deep need of a shower.]  Of our twelve squash and zucchini plants (borers love zucchini too), nine had borers in them.  So now it’s repair time for the plants.  I bury the stems, packing soil all around the surgery spots.  If all goes well, the plants will grow new roots at these spots, enabling them to survive.  Time will tell.

A few days later, it looks as if most of our plants are surviving.  There are two casualties who are wilting pretty badly, but the others seem strong.  Fingers crossed that we got all the borers, and that the surgery wasn’t irreparably destructive.

A few of our plants look like this — the wilted leaves have had their water & nutrient supply cut off by the borer and surgery.  But there are a few leaves standing strong, with some new ones popping up, which means that some of the vine is still intact.  I can only hope for new root growth at this point, otherwise I’ll have to pull the plant. 

In total, we’ve lost about 40% of our squash and zucchini plants to the borers so far this season. That’s not the end of the world, since we still have several healthy plants. We’ll have to wait to see if there are any borers we missed — it will become evident in the next few weeks if the leaves start dying.  I don’t think I’m up for doing any more borer surgery this season, so we are just going to take what we can get.  So far we’ve eaten four absolutely delicious squash from our garden — three more than we had last season — so even if we don’t get any more, I’m chalking that up as a win.

Reflecting on this experience — which was pretty rough given my extreme squeamishness about bugs — I can understand why people use pesticides.  It would have been MUCH easier to skip the tinfoil wraps, home-made traps, masking tape egg removal, crazy butterfly nets, and of course the heinous surgery — and just spray some toxic pesticide on the plants.  But I couldn’t do that, knowing that those pesticides would become part of our environment and part of our bodies.  So would I do this all again?  Yes, I would.  But if surgery needs to happen again next season, I’m enlisting my son to do it.

2 views0 comments

Recent Posts

See All


bottom of page