Pumpkins and squash are some of the most popular vegetables to grow in the summer. They are generally easy to grow and the harvest is bountiful. However, pumpkins and squash can suffer a horrible fate by being eaten by squash bugs. While it may seem that for every 1 you kill 10 more popup in their place, there are some natural ways to get rid of them and deter them from coming back.
The number one way to get rid of squash bugs is to hand-pick them off of the plants. The best time to do this when they first show up. Take a bowl, jar, jug or whatever you have and fill with water and a few squirts of liquid soap. Hand pick or use a table knife to scrape off the adults and any nymphs you see and using your fingernail or a knife. You can also scrape off eggs, or simply cut the leaf and dispose of it. If you prefer, using a small shop-vac with an inch or so of soapy water in the bottom to suck them up also works with the adults and nymphs, just remember that too much suction will suck up your leaves as well. It probably isn't very efficient to drag a shop vac through the garden either, so put on your big boy or big girl pants and use your hands. You can put on a pair of gloves if the thought of touching the bugs makes you too squeamish, but since they do not bite or sting, so there's no harm in handling them. During the early stages of plant growth, you may want to use floating row covers to protect them. This will not guarantee there won’t be anymore, but it does keep the numbers down. These methods also work best when combined with one or more of the following methods. Some squash has a quick maturity window and many gardeners report that squash planted in late summer and early autumn don't seem to be plagued as much by the critters. This won't help for pumpkins or hard shelled squashes that need a longer maturity window, but summer squash like crooknecks and zucchini are good candidates for a later planting.
Using cedar mulch can also help to deter them as they do not like the smell. Making a tea out of cedar and putting it into a squirt bottle can help deter them as well. Put cedar chips into a pot of hot water. Boil for about 15 minutes or so, the longer the better. However after 30 minutes it’s pointless. After the liquid cools, strain the chips and pour into your squirt bottle. Add a drop or two or dish liquid as well, but only spray in the late evenings or on cloudy days. The dish liquid helps the water to 'stick' to the leaves better. You don't need more than a drop or too to be effective though.
Neem oil is also effective. It is a safe, natural insecticide that isn't toxic to anything but insects. However, it is found that neem, used correctly, does not harm the pollinators, such as bees and butterflies. It only hurts the insects that eat the plants. You can find it at your local gardening or hardware store. The best to use is the 70% and you will still want to dilute and mix it thoroughly. The mixture is good for killing squash bugs in all stages from eggs to adults. Be careful about not spraying too frequently though. Overuse can cause more damage than it fixes. Generally spray no more than once every 10 days or so. Do not use during the hot part of the day either. It is oil and can cook your plants with the heat from the sun. The best time for use is generally during cloudy days or evenings when it’s starting to cool.
Companion planting is also effective at deterring squash bugs. Nasturtiums, tansy and gardenias put off a smell that the bugs cannot stand. After planting these near your crops, you will notice a reduction in the squash bug population. Marigold and oregano can also help to deter the bugs from setting up house on your plants. Dill will repel the bugs, however, planting it near squash can kill the vines. Using the dill plant’s leaves only, scatter them all over your squash or pumpkin plants.
Left untampered with, squash bugs can multiply quickly and decimate an entire crop. Keeping their numbers down is key to having any type of harvest from your plants. While nymphs only take a month to mature, the female is still laying more eggs. Within a couple of months, plants and fields can be overrun. Deterring them early on will be your best bet.
Squash bug image courtesy of BugFiles