Thursday, July 12, 2012

AAAUUUGGGHHHH! Blog Episode One: The Squash Vine Borer

I suppose it had to happen sooner or later. This gardening season was going very nicely. No major problems except for the odd little weevils that attacked, skeletonized and destroyed the mustard greens in my mesclun salad mix. It was ONLY the mustard greens. Apparently, we have very discriminating weevils in Nebraska. Who knew?

I dislike the mustard greens anyway, so no biggie to me.

But this. This is unacceptable.

I stepped out to the garden to water the plants in pots and examine the tomatoes for peak ripeness. That's when I noticed the squash plants didn't look right. By 'right' I mean they didn't look green and upright. In fact, they looked downright yellow and wilty.

So I grabbed the hose and, as I started watering, wondered how on earth I could have missed them yesterday. Upon closer examination, the truth was revealed: tiny, itty, bitty little sawdust-y holes at the base of some of the vines.

Squash vine borers! AAAUUUGGHHHH! I almost choked on my gum.

After a few moments of impolite comment, I reluctantly pulled out the vines that looked the worst and examined the remaining plants for holes. Not all of the vines were affected and, after some research, I concluded that they must be the butternut squashes I planted. Butternuts, for some reason, seem to be less affected by the borers. I'm still working on my seedling labeling skills so I'm not really sure which varieties are still alive.

Here's what I learned about the borers today: Squash vine borers overwinter in the ground as pupae and emerge in the summertime as adult, clearwing moths whereupon they set out in search of a likely looking squash plant on which to mate and lay eggs. When the eggs hatch, the little larva bore into the vines and take up residence inside the stem blocking the flow of water and nutrients to the plant which eventually dies. Once the larva matures, it digs down into the ground to pupate so it can emerge next year to ruin someone else's squash plants.


Organic controls of the squash vine borer are aimed more or less at prevention rather than destruction. Basically, the idea is to exclude the adult moths from your baby vines. This is best accomplished by learning to identify the adult moths and then, once you spy them buzzing around, using floating row covers or another mesh type barrier with tiny holes to keep the adults from laying their eggs on your plants. The eggs are most likely to be laid during the second half of June or so in my neck of the woods so putting up the covers for a few weeks during June and July should do the trick.

If you really want to try to save the affected plants you have, there is one thing you can try. Sterilize a sharp knife and use it to slit the stem of the affected vine upward starting at the point where the larva bored into the stem. When you locate the larva (or larvae), stab the heck out of it/them with the knife. Then carefully reposition the vine and bury the cut portion in the garden with dirt and keep it moist. With luck, the vine will put down more roots where it is buried and the plant may live. Then again, you might wind up with a dead squash plant buried neck deep in your garden.

Fortunately for you and me, the borers only have the one generation every year. So, chances are they have probably done the damage they were going to do already. It's going to be close, but I think I can set out another planting of seed and maybe get a few squashes before winter sets in. The seed packets all say 95-105 days to maturity and I have right about that many days until first average frost. I have nothing to lose but the rest of my squash seeds, right?

At least next year, I'll be ready for them. The little...darlings!


  1. Boo to squash vine borers! Someone told me companion planting was the way to go, but I don't know squat about it!

  2. There's a thought! More research coming up!