Few pests can take out a healthy plant faster than a squash bug. But how do you get rid of squash bugs, especially if you’re trying to garden organically? With the following 10 tips, you’ll be armed for battle against these ruthless garden invaders.
One day, your squash plants are lush and thriving. The next, several leaves are yellowing and crisping up around the edges. Within a week or two, the plant has died completely, with nothing but dry, withered, brown vines and leaves and a wrinkled, immature squash or two to show for your hard work and care.
So what happened?
More often than not, squash bugs are the culprit.
Squash bugs are my sworn enemies, and I wish suffering upon them all. For the past two summers, I’ve been gardening in a small plot in my community garden, as well as in containers on my front porch.
Community gardening presents some unique challenges, but squash bug infestations have proved the most frustrating. In the past two years, I’ve lost watermelon, honeydew, and all manner of summer and winter squash plants to those pesky insects. My cucumbers have remained unscathed, but only because I grow them in containers at home.
In the process, though, I’ve learned a lot about how to prevent and get rid of squash bugs to keep my plants healthy.
Why are squash bugs a problem?
Squash bugs are fairly large, beetle-like insects who live their entire lives on or near squash plants. Where I live (Utah), they usually emerge in May and then wreak havoc through the remainder of the gardening season.
These pesky bugs pierce the vines and fruits of cucurbit plants, sucking out their juices and ultimately weakening or even killing the plant. The holes interfere with water and nutrient absorption and provide a way for infections to enter the plant. In addition, their saliva can carry bacteria that further harms your squash plants.
The leaves of cucurbit plants affected by squash bugs will quickly wilt and turn brown. Gradually, entire sections of the plant, and ultimately the entire plant may die.
How to identify squash bugs
It’s better to find squash bugs before they start damaging your plants, so keep an eye out for them. Adult squash bugs are between 1/2 inch and 3/4 inch long. They have brownish gray bodies that can be striped around the edges. They are roughly teardrop shaped, with a triangular area leading to their heads. When you squish them, you’ll discover that their innards are bright turquoise and unpleasantly smelly.
Immature squash bugs have white to pale green bodies that are oval shaped. They have black heads, black, spindly legs and are about a 1/4 of an inch long.
Newborn squash bugs have small green bodies with black heads and are most identifiable by their spidery black legs. You’ll generally find them on the underside of leaves, newly emerged from their eggs.
No matter their age, squash bugs are absolute jerks, and you should kill them if you value your squash, cucumber, and melon plants.
So how do you get rid of them? Unfortunately, a full-blown squash bug infestation can prove difficult to contain. As a result, prevention and vigilance are your best tools in keeping the squash bug population in your garden under control.
10 Ways to Get Rid of Squash Bugs Organically
1. Rotate planting locations
Squash bug eggs and nymphs won’t survive a hard freeze, but adult squash bugs overwinter in brush, wood piles, and any mulch, woody compost, or plant debris leftover in the garden after autumn.
Since you can’t expect the cold to kill them, instead rotate your plantings each year so that the previous year’s squash, melon, or cucumber beds house something from a different plant family. Move those cucurbits to an entirely different part of the garden. Then cross your fingers that the squash bugs don’t find them.
2. Grow vine varieties up a trellis.
Squash bugs love to hide in the soil and plant debris right around the root of cucurbit plants. Getting your squash leaves away from the ground can make the area less appealing for these destructive insects. Vine varieties grown up trellises are a great option for making your garden less appealing to squash bugs.
3. Plant decoys and repellants
Like many insects, squash bugs dislike the scents of particular flowers and herbs. Interplanting marigolds, nasturtiums, mint, and beebalm with your squash, pumpkin, cucumber, and melon plants can make those cucurbits less appealing to squash bugs.
Another trick is planting a decoy squash plant – blue hubbard squash works especially well because squash bugs love it – on the perimeter of your squash bed early in the season. This plant acts as a trap and egg-laying sight for the squash bugs in the garden.
Once the plant is established and squash bugs have laid eggs on it (but before the eggs have a chance to hatch) remove the trap plant and dispose of it. Then treat the ground with one of the natural insect repellents listed in steps 8 and 9. You can then follow this up with a new planting of your main cucurbit crops.
4. Clean up garden debris
As mentioned above, squash bugs love to hide under mulch, dead leaves, and other garden debris. So keep those garden beds tidy! Clear out garden debris any time you spot it, and throw it straight into your compost pile.
5. Check for eggs daily
Tedious though it may be, this is one of the single most effective methods of preventing a full-fledged squash bug invasion. A single female squash bug can lay 250 eggs, and each of those eggs quickly mature into adulthood, so just imagine how fast things get out of control.
To keep that from happening, head out to your squash plants every day and, with garden gloves on, turn over each individual leaf. If you find a patch of small yellowish-brown eggs sticking in the crevasses of the leaves, cut off the leaf altogether and throw it away.
Alternatively, you can press duct tape to the eggs and then peel the eggs away from the leaf. Be careful not to damage the leaves in the process, but even if you do, you’ll still do less harm than a clan of squash bugs.
6. Get rid of squash bugs daily
This is the other finicky step that’s necessary to prevent a squash bug infestation, but you really do need to go on a squash bug hunt and kill mission every day, or at least several times each week. My preferred method involves wearing gloves, catching squash bugs by hand, and dropping them in a combination of water, neem oil, and dawn dish soap. Squishing is also an option.
Not seeing any squash bugs? They hide in the heat of the day, so I’ve found more of them early in the morning or near sunset. Watering deeply also drives them out of their hiding places.
7. Set a squash bug trap
Want to make the process of finding squash bugs easier? Set a trap for them.
Lay out an old board, large rock, or piece of heavy cardboard near the base of your squash plants and leave it there for a day or two. Leave it overnight for squash bugs to congregate underneath. The next morning, turn the trap over and quickly squish or drown all of the squash bugs you find underneath.
8. Sprinkle diatomaceous earth
Though not an insect poison in the traditional sense, diatomaceous earth’s rough surface slices up the bodies of squash bugs. You can sprinkle a small amount right around the base of your pumpkin, squash, cucumber and melon plants to kill or deter any squash bugs in the area.
However, I recommend avoiding wide-spread diatomaceous earth use, because it can harm beneficial insects too.
9. Create an organic spray
Neem oil is a food safe, organic product that you can use on a wide variety of insects (don’t let the smell put you off!). Mix it up with hot water and a bit of mild dish soap (I like to use peppermint castile soap), and then spray it on any squash bugs that are too quick to catch or squish.
Unfortunately, a neem oil spray will only work if you get it directly on squash bugs bodies. As a result, I try to spray it in the soil near the root of the plant, where I know squash bugs tend to hide. Avoid using it early in the day or in full sunlight, though, since it can scorch your plants. Using it late in the evening works best.
10. If you can’t seem to get rid of squash bugs, take a break from planting squash
If all else fails, it’s may be best to avoid planting cucurbits for one year so that the squash bugs that overwintered in your garden don’t have anything to survive on. Sometimes a break is essential for long-term success.
To be honest, this is where I’m at. I’m throwing in the squash towel for the year, at least in my community garden! I’ll still grow cucumbers and maybe a summer squash or zucchini in containers at home. Hopefully in another year, the worst of my community garden’s invasion will be under control.
Armed with these tips for getting rid of squash bugs, I’ll be ready for squash and pumpkins and melons galore!