A few drops of the right essential oil mixed with water and a small amount of soap can make an effective DIY stink bug spray. The best-performing oils, based on field research, are clove, lemongrass, and spearmint, which blocked nearly 100% of brown marmorated stink bugs from approaching baited traps when tested individually. Combining all three in equal parts worked just as well. Here’s how to make these sprays at home and use them without damaging your plants or siding.
The Most Effective Essential Oils
Not all essential oils work equally against stink bugs. A study published in the Journal of Applied Entomology tested eight oils as spatial repellents for the brown marmorated stink bug, the species responsible for most home invasions in North America. Clove oil, lemongrass oil, spearmint oil, and ylang-ylang oil nearly eliminated stink bug activity near treated areas. Wintergreen, geranium, pennyroyal, and rosemary still performed well, reducing stink bug presence by 60 to 85%.
The active compounds driving this repellency include eugenol (the main component of clove oil), citral (from lemongrass), and carvone (from spearmint). Each of these individually reduced stink bug trap catches by 72 to 99% in field trials. A 1:1:1 mixture of clove, lemongrass, and spearmint oils matched the performance of the best single oils, making it a practical blend for a homemade spray.
Basic Repellent Spray Recipe
For a general-purpose stink bug repellent you can spray around windows, doors, and other entry points:
- Water: 2 cups (16 oz)
- Essential oil blend: 20 to 25 drops total of clove, lemongrass, and spearmint oil in roughly equal amounts
- Liquid dish soap: 1/2 teaspoon (acts as an emulsifier so the oil mixes with water)
Combine everything in a spray bottle and shake well before each use, since oil and water separate quickly. Spray around window frames, door frames, foundation cracks, and any gaps where stink bugs typically enter. Reapply every few days or after rain, as essential oils evaporate and lose potency relatively fast.
If you don’t have all three oils, clove oil alone is a strong choice. It was effective at the lowest release rate of any oil tested in the field research (just 14 milligrams per day), meaning a little goes a long way.
Soap-Based Kill Spray
Essential oil sprays repel stink bugs but won’t reliably kill them on contact. For a spray that does, insecticidal soap is the simplest option. Mix 1 to 2 tablespoons of pure liquid castile soap (or a mild liquid dish soap like Dawn) into a quart of water. Spraying this directly on stink bugs disrupts their outer coating and kills them, though it only works on contact. It has no residual effect once dry.
You can combine the soap spray with essential oils for a formula that both repels and kills. Use the same recipe above but increase the soap to 1 tablespoon per 2 cups of water. This gives you a spray that deters stink bugs from treated areas and can dispatch any you find crawling around.
Neem Oil for Garden Use
If stink bugs are feeding on your tomatoes, peppers, or fruit trees, neem oil is a better ingredient than essential oils alone. Its active component interferes with insect hormone systems, disrupting feeding, growth, and egg laying. It works as both a repellent and a slow-acting insecticide. Mix 1 to 2 tablespoons of cold-pressed neem oil with a teaspoon of liquid soap (as an emulsifier) in a gallon of water.
Spray neem oil solution on plant foliage in the early morning or evening, never in direct midday sun. The sun breaks down the active compounds quickly and increases the risk of leaf burn. Coat both the tops and undersides of leaves where stink bugs feed. Reapply every 7 to 14 days during active stink bug season, which typically peaks in late summer and early fall.
Avoiding Plant Damage
Homemade sprays can burn foliage if you’re not careful. Dry dish soaps and laundry detergents are too harsh and should never be used on plants. Stick to pure liquid castile soap or a very mild dish soap.
Always test your spray on a small section of the plant first and wait two days to check for damage. Signs of injury include brown or yellow spots, wilting, or a bleached appearance on the sprayed leaves. Some plants are more sensitive than others. If you notice mild damage, dilute the solution further. You can also reduce the risk by rinsing or wiping the leaves a couple of hours after spraying to remove any residue before it has a chance to cause harm. Using the lowest soap concentration that still controls the bugs is the safest approach.
Protecting Home Surfaces
When spraying around windows, doors, and siding, oil-based sprays can stain certain materials. Aged or weathered vinyl siding is particularly vulnerable, and some homeowners have reported permanent yellowing from oil-based pest products that caused an irreversible chemical reaction. Brick, stucco, cinder block, and bare wood can also develop visible stains.
Before spraying your entire home’s perimeter, test a small, inconspicuous area and let it dry completely. High heat and humidity increase the chances of staining. If any spray lands on painted or stained surfaces, wipe it off immediately with soap and water to prevent discoloration. For light-colored siding, consider using the spray only on window and door frames rather than broad surfaces, or apply it to cotton balls or cloth strips placed near entry points instead.
Getting the Most Out of DIY Sprays
Timing matters more than most people realize. Stink bugs move indoors starting in mid to late September in most of the U.S., seeking warm shelter for winter. The best time to spray entry points is before this migration begins, ideally in early September. Once they’re already inside your walls, exterior sprays won’t reach them.
For indoor stragglers, a simple solution of soapy water in a wide-mouth container works better than any spray. Stink bugs drop when disturbed rather than flying away, so holding the container beneath them and giving them a light nudge sends them straight into the soapy water, where they drown. This avoids the smell released when stink bugs are crushed or sprayed aggressively.
DIY sprays work best as part of a broader approach. Seal cracks around windows, repair torn screens, and caulk gaps around utility pipes. No repellent spray can compensate for a home with easy entry points. The spray keeps stink bugs from lingering near those entry points long enough to find their way inside.