Gardening is a constant learning experience. Just when you think you have it down, you're thrown for a loop. And that goes double for vegetable gardening.
My squash have been doing pretty well. I've posted proudly that I am actively harvesting and shown photos of the abundant foliage and hearty plants. But something had been bothering me. In the back of my mind, I knew there might be something wrong.
Look pretty good, right? All of these photos are taken on the same day. The plants looked healthy.
But I had started to see some yellow foliage on one of the plants and I was seeing wilting late in the day on all of them. But I chalked it up to no rain in three weeks and very high temperatures-90s and 100s. Then I started seeing flowers dried up and not producing. I checked out some pictures online so I knew what to look for and I headed out to the garden.
And it didn't take me long to find the telltale signs.
Squash vine borers.
Above, at the end of my knife, you see the "frass", which is the evidence of a bore hole, basically the stuff the borer leaves behind as he bores in. Looks similar to sawdust. Why was I carrying a knife, you ask? Because I was determined to try and save my plants and get those borers out. If you're checking and you don't see any frass, make sure you lift up the squash stems, which usually lie along the ground as they get big. The borers usually enter from the underside and leave their evidence hidden unless you look underneath. If you see slight splits in the stem, this could be the entry. It's not always completely obvious, but the frass does make them easier to confirm.
If the damage is not too extensive, you can try to split the vine, up a ways from where the frass is located, as the borer has already begun moving up inside the stem. You can dig out the borer, dispose of him, and then cover the stem with mounded up dirt to both protect the incision you have made and encourage further rooting of the plant and pray for survival.
It doesn't always work out. I found borers in EVERY ONE of my squash plants- sometimes 2 borers in a plant. In three of my plants the damage was too extensive by the time I got the borer out , the plant was demolished. Because splitting the vine up the middle and opening it to get the borer is not easy and not gentle.
Above you can see the split I made and the tip of the borer just visable above the split. Here's another.
Another below just visable at the top of the incision
And another below just barely visible at the top of the cut-because you basically just guess how far up he has gone and try to limit your damage
And they're darn hard to see as they are so close in color to the inside plant material.
Here's a picture of the plant after surgery and I have mounded it over with dirt.
What can be done to stop these buggers? Watch for small brown eggs on the underside of the leaves and at the base of the stem. I also applied Bt to the plants which will kill the borers if they ingest it. But I will say I don't think I did a good enough job putting the Bt at the stems along the ground, the most likely entry points. And I relaxed a few weeks ago, letting my applications slide as I felt maybe we had passed the danger zone.
As I sat there feeling like a surgeon who has just done a marathon operation, the first rain in 3 weeks raining down upon my head and pasting my hair to my face, I gave the 5 remaining plants a 20% chance of survival. 2 days later they are still alive so here's hoping some patron saint of squash is looking down on me kindly, rewarding me for trying to save my crop.