Squash bugs are one of the hardest pests to get rid of once they find your garden. It can be devastating to walk out to your garden and find your beautiful squash plants wilted on the ground. Crop rotation is helpful, but only if you have a lot of room to rotate about. Chickens and guineas, at least mine, don’t really care for squash bugs either. But fortunately all isn’t lost. If you combine the following 6 tips, you can effectively control squash bugs and keep them from taking over your garden this summer!
1. Hand pick off the bugs and eggs
This is, and always will be, the best method of defense when it comes to squash bugs. The most reliable way to get kill them is to do it yourself. I keep a jug of soapy water in the garden specifically for this purpose. Bug picking is best done in the morning or evening- simply go through your plants and pick off any adult bugs to find and drop them into the soapy water. Adult squash bugs are usually found on the underside of the leaves, especially the lower leaves that are touching the ground. They will also be found around the base of the plant. You will find rows of gold-colored eggs on the undersides of the leaves. You will also want to scratch off and destroy these eggs. Try to do this with the least amount of damage to the leaves. You can simply squish them, brush them off into your soapy water or use very sticky tape to pick them off. This is a daily job and if you get lazy about picking- chances are your squash plants will fall!
2. Companion plant
You can also help control squash bugs by planting repellant plants with your squashes. Two of the most commonly used companions for squash is nasturtiums and white icicle radishes. Plant them throughout your squash beds for the best results. Other plants such as oregano, marigold, calendula and dill can also provide some protection.
3. Attract beneficial insects
The problem with most insecticides- even those labeled “organic”- is that they don’t differentiate between the good and the bad. Certain insects are very beneficial to have on your side when you are fighting pests. One such insect is the Tachinid Fly, or Trichopoda pennipes. This little fly is very effective in helping to control squash bug populations. The female fly lays her eggs on the adult squash bugs and they will hatch and burrow into the host to feed, killing it. If you companion planted dill or calendula with your squash plants their pollen and nectar rich flowers will help to attract the Tachinid Fly.
4. Diatomaceous Earth
Diatomaceous Earth is a powder made from ground up diatoms. It works my making microscopic cuts in the exoskeleton of insects- drying them out. There are 2 types- food grade and industrial grade. You want the food grade for all of your gardening and pest needs. Simply spread a layer of diatomaceous earth at the base of the plant. It doesn’t work once it gets wet, so you will have to reapply as necessary. DE does not work as well on adult bugs due to their hard shell, but the nymphs are usually the most destructive and they don’t have such a hard shell. Take care not to get DE on the blossoms, because it will not differentiate between a squash bug and a bee, lady bug or Tachinid fly. So be careful when using it.
5. Watch your mulch
Squash bugs love to hide under the mulch around your plants and it provides the insects with a protective cover. If you must mulch, do not put it right up against the base of the plant, or try something like plastic sheet mulching instead.
6. Over-plant your squash
The more plants you have the more there is to go around! The first year I planted yellow scalloped squash, I planted 3 along with my usual zucchini. What I discovered is that the squash bugs preferred the yellow scalloped squash over the green zucchini. From that year on, I have planted a few sacrificial scalloped squash. I still use the above mentioned control measures, but the sacrificial squash plants are usually the first to be swarmed and fall. This also works if you just plant more plants than you really need- that way it isn’t quite so devastating if the squash bugs win the battle. You can also try planting varieties, such as butternut, that are not favorites of the squash bugs.
Another thing to keep in mind when trying to control squash bugs is to know your climate and insect life cycles. I know a lot of gardeners who can successfully plant squash later in the season and skip the squash bugs all together. In my gardens, I have always found that early is better. That way I get a good month or 2 of squash harvests before the bugs get really bad. Experiment with planting times and see if a spring, early summer or late summer planting works better for you.
Good luck and Happy Gardening!
© 2014 – 2016, Sarah R Toney. All rights reserved.