Adult stink bugs are easy to recognize. They are relatively large, growing up to ¾" long, and have distinctive shield shaped bodies. They may be green or brown. When held or squished they emit a foul smelling fluid, hence the name stink bug. Young stink bugs are smaller, rounder, and more colorful, with highly patterned black, red, white, and green colored bodies.
Stink Bugs feed on plant sap using their needle like mouthparts. They can be found in large numbers feeding on the buds, flowers, fruits, and seeds of many types of plants including beans, okra, tomato, pecan, peaches, eggplant, and blueberries.
Their feeding damage often causes fruits and seeds to be misshapen or shriveled, and leaves behind a small pin prick injury on the fruit or seed skin. On tomatoes, their feeding causes cloudy areas of hard yellow spots to form just under the skin.
We prefer not to use pesticides if at all possible in our gardens, so a couple of years ago we started experimenting on a way to deter them from feeding our tomatoes and other vegetables.
We knew from experience that they cannot stand spearmint, peppermint, garlic or catnip, these are the ingredients most often used in DIY deterrents and from our own experience with using them, so we started working on different blends of these.
The key we found is first only using fresh herbs and garlic, this gives the most protection.
We wanted a powder form that is easily applied, and created a formula that worked extremely well. We also made a spray from this formula, but this was more time consuming and did not last as long as the powder in our opinion. So we stuck with the powder formula and applied it during the day after the dew had dried.
This seemed to have solved our problems except for one setback, every time it rained, it washed the powder off, and as the soil would often be too wet to walk for a day or so after the rain, the stink bugs would make an amazing recovery and be back before we could re-apply the powder.
We found that the solution to this problem was making a second formula from the cut herbs and garlic and sprinkling this on the ground before a rain, this holds them at bay for a day or so until the powder could be reapplied. We tried using the cut formula on the ground full time, but it just wasn't as effective as the powder applied to the foliage.
The combination of powder and cut formulas has worked very well for us and we recommend everyone try it. If you grow your own herbs and garlic you should keep some back to make this with. Drying the herbs and freezing them seems to keep them very well.
Anyone can make up their own Natural Stink Bug Deterrent, but for those that do not wish to go to the trouble, we are making our blend available.