Q. Mike: I need to know how to control stinkbugs. I have problems with the Southern Green, Brown, and 'regular Green' types.
- ---Kurt in Southwest Louisiana
- ---Laurel in East Tennessee
- ---Paula in Doylestown, PA
- ---Steve in Delaware
But not on non-flowering ones like that cabbage, broccoli and cauliflower. While constant attention is necessary to prevent the various damages stink bugs cause to a huge number of garden plants (including white lumps under the skins of tomatoes and cat-facing of tree fruits in addition to the complaints above and many, many others), they are easy to control on plants that don't need to produce flowers.
Row covers, as we have often explained, are rolls of sheer, curtain-like fabric made of spun polyester; Reemay is one big brand name, but there are several others. Stretch the covers over your young plants, secure the corners tightly, and light, air and water will reach those plants just fine, but insect pests will NOT. Run the covers over metal hoops and plants that need no pollination can spend their entire season under their protection.
I like row covers a lot. You only need to buy them once; and they trap warmth, allowing you to start a little earlier in the season, and continue a little later. They even help plants grow faster in the Spring. AND they vent heat so well you can leave them on all summer. They can even be used to protect flowering plants early in the season, when those plants are most vulnerable. Just remember to remove the covers when the first female flowers appear, so pollinating insects can get to work for you.
But don't waste row covers on garlic—its one of the few crops stinkbugs won't bother. In fact, it can be used against the pests; just soak your plants with a garlic repellant spray at the first sign of stinkers next season. Or use neem; made from the seed of a tree native to India and Africa, neem is both a feeding deterrent and a true insecticide for those insects what are not deterred.
You can also handpick or vacuum up the adults, who are distinctly shield shaped, unusually wide, about half an inch long, come in many color variations and stink when you squish 'em. IMPORTANT NOTE: Two highly beneficial insects look a lot like these pests. So don't harm 'stinkbugs' with sharp points on the tips of their shield (that's the super-excellent spined soldier bug) or two 'eye' markings just below their head (the two spotted stink bug). They are both innocent of crop damage but guilty of pest insect assault!
To prevent serious outbreaks of bad stinkbugs, tape a mirror to the end of a hoe and use it to search the undersides of leaves. Then destroy the barrel shaped eggs of the stinkers, which are laid in fascinating geometric clusters, like double rows and triangles.
Keep nearby weeds mown; they really like weeds. In fact, many experts feel that the most serious problems occur when stinkbugs breed into very large numbers in weeds near the garden and then go looking for trouble.
Grow lots of flowering herbs—especially dill and fennel—to attract tachnid flies, big-eyed bugs, assassin bugs, damsel bugs and other beneficial insects that prey on stinkbugs in their egg and larval stages, before they can damage your plants. You can also attract or purchase parasitic wasps that perform the same task. So small you could mistake them for the period at the end of a sentence, these mini-wasps are ferocious predators of these and other pest insects, and are widely available mail order.
Insecticidal soap and oil sprays—like that canola oil-based Pyola our Tennessee listener is using—can be very effective, if they are used correctly. Soap and oil can only kill insects on contact, by smothering them. Just spraying the plants when the bugs aren't there is a waste of soap and oil—you have to soak the bug to kill the bug.
And finally, back when I was Editor of ORGANIC GARDENING magazine, we recommended throwing a bed sheet over large areas they were infesting, shaking the plants underneath the sheet, waiting a minute for the dislodged stinkbugs to latch onto the sheet, gathering it all up quickly, taking it to a flat surface and stomping on them. It's a little old-fashioned, but surprisingly effective. Just try and keep the glee factor down.
Check out this PREVIOUS QUESTION OF THE WEEK for some advice on what to do when stink (or other) bugs invade your home in the fall and winter.