I have never hated a pest quite as much as the Squash Borer, Melittia cucurbitae. They are not just simple annoying garden pests. They are the epitome of evil that cause total destruction and death of otherwise perfectly beautiful, productive plants.
These loathsome black and red flying insects will lay eggs on squash plants around the time the plants reach their mature size and start to bloom. This happens to precisely coincide with the time that gardeners start to feel a sense of pride and accomplishment gazing upon their lush green gardens. Then, BAM! The eggs hatch, and nasty little larva bore into the base of the vines to begin feasting and destroying. Our pristine early Summer gardens are suddenly plagued with sickly looking wilted squash. The tiny eggs and harmless looking adults usually go unnoticed. So, by the time the damage is done, it is usually, too late to save the vines. When borer damaged vines are examined, holes surrounding by what appears to sawdust are found near the base of the plants. The disgusting slug like larva that cause the damage are usually out of sight, happily nestled in the hollowed out vines.
The following links can help you learn more about the life cycle of these evil bastards.
If you just want to know more about how to kill them or how to grow squash in spite of them, proceed.
If you Google “how to kill squash borers”, you will not find any definitive instructions on how to effectively rid your garden of these pest. Instead, you will find lists of borer control methods that are sometimes expensive, often hilarious,usually quite tedious, and almost always a waste of time. I, and members of my family, have tried the following ridiculous methods to save our precious squash.
Ways to waste time and energy trying to save squash from borers:
- Catch and destroy the parents before they have a chance to lay eggs. Done by hand or with a net? Waste of time. With yellow traps filled with water? No luck.
- Hand pick the eggs. Maybe if you have an excessive amount of free time, a strong back, and a magnifying glass. You won’t find all of them, and your neighbors will think you are mad.
- Spraying and injecting the vines with Bacillus Thuricide. This is the most expensive thing I’ve tried. $16 for a bottle of BT and $6 for syringes to save a few squash vines? It would have to be applied frequently to be successful, and cost far more than the value of the squash. BT is however a great insecticidal measure that can be reasonably used with success on other crops.
- Surgically removing the borers from the vines with a razor blade (my personal favorite because of the revenge aspect.)
- Surgical removal of the larvae followed by insertion of a tampon inside the vine to allow the plant to still take up water and nutrients. This method might be successful in keeping the vine alive. But, probably only temporary and once again your neighbors with think/know you are crazy.
After trying every thing on this list, on the internet, and under the sun to rid our garden of squash vine borers. I had to consider how valuable my time is and how cheap squash are at the grocery store. There was a voice of reason (named Alex) telling me that it wasn’t worth the trouble. So, I said I wasn’t going to give squash a place in the garden anymore. Well, I lied.
I stewed over it all winter last year and decided I was determined to have squash in spite of the borers! Squash is not my absolute favorite crop. But, I still had to figure out ways to grow it. I could not be beaten by these bugs! I had to win.
So how did I beat the borers? I didn’t. Instead of obsessing over killing them or altering their life cycle. I decided to plan the Summer garden considering that there would in fact be borers and they would not be stopped. Variety selection and timing were planned accordingly and we ended up harvesting plenty of curcubits. I felt like a winner when I cooked with and blogged about our delicious squash (Stuffed Patty Pan with Prosciutto and Chanterelles and recently shared Golden Nugget:a Perfect Winter Squash). I plan on growing plenty more squash this Summer using the same planning as last year.
How to really beat the borers or grow squash regardless of them
- Plant borer resistant varieties. There are many different opinions on which varieties are the most resistant and it may vary regionally. The one variety that seems to be completely borer resistant is Tromboncino. It is a cultivar of the Curcubita moschata species which includes many vining Winter squash. Tromboncino can be picked young and used as a zucchini substitute or allowed to mature and be stored as a Winter squash. They are insanely productive huge plants that need plenty of room. Of all of the varieties I planted, they are the only one that did not get damaged at all by the borers. For bush type plants, I have had better luck with White Patty Pan (scallop) Summer squash than any others. They do eventually get bored, but they are somewhat resistant. Cushaw squash are known to be resistant as well. I can not attest to the truth of this because I have not grown them yet. But, they are in my garden plans this year. Hopefully next Fall I will be blogging about Cushaw pie.
- Plant varieties of squash that are less desirable than your neighbor’s squash. The favorites of the borers seem to be yellow squash, followed by zucchini, with patty pan third, followed by most winter squash. If you have patty pan squash next to a field of yellow crook neck, the patty pan will outlast the field of yellows. I have heard of gardeners planting yellow squash in an area nearby their main garden to occupy the borers and keep them out of the more prized and slower producing varieties of squash.
- Plant the more susceptible varieties early and plan on pulling the plants and replacing them with late season crops as soon as the borers arrive. Accept that they will be crops with a shortened season. Pull them at the first sign of borer damage, and burn the plants to destroy the bugs. If you allow struggling squash vines that have been bored to stay in the ground, the larvae will be able to complete their life cycle and eventually produce more devil bugs. So, pull them, burn them, and move on with positive crop rotation. A late squash crop is a great way to follow plantings of bush beans or determinant tomatoes.
Careful garden planning is definitely the best way deal with squash vine borers. I’d rather spend more time enjoying Summer, and less time on hands and knees in the garden performing surgeries on squash vines. My neighbors probably still think I’m crazy.