Grasshoppers can pose a significant threat to your garden or farm, since they can live for months and are particularly destructive in the juvenile (nymph) stage. They will generally eat any plants but especially favor young green ones like grasses, lettuce, carrots, beans, corn, flowers and onions,^1,2 and they tend to avoid eating tomato leaves, squash and peas.¹

Have other pest problems? Visit our resources on Managing Pests and Weeds.

6 Natural Strategies for Managing Grasshoppers

1.    Hand Pick Insects & Protect Plants

If you have a small amount of grasshoppers, you can hand pick and squash them.² Another way to protect your plants from hungry grasshoppers is to cover them with metal window screening or screened boxes, since grasshoppers can chew through cloth row covers.²

2.    Grow a Green Border

If you know that grasshoppers tend to migrate through your home garden, you can grow a "trap crop"- a border of tall grass or other green plants around your garden. This will attract grasshoppers to the trap crop, and keep them busy instead of entering your garden to eat other plants. Be sure to keep the trap crop healthy, green and tall.²

3.    Natural Predators

When it comes to getting rid of these pesky hoppers, there are natural critters that can help. Many species of birds are natural predators to the grasshopper,^1,3 so attracting more birds to your garden by setting out bird feeders can help put a stop to a grasshopper infestation. You could also keep chickens, guinea hens, or even turkeys! However if you keep poultry, make sure to cover garden areas to prevent destructive scratching by chickens.² Other natural predators of grasshoppers are wasps, ground beetles, robber flies, coyotes and parasitoids such as hairworms, tachinid flies and flesh flies.^1,4

4.    Neem Oil

If you want to give nature an extra hand, neem oil can be an effective natural alternative that deters and slows down the activity of grasshoppers.⁵ A neem oil solution which can stunt or fully halt grasshopper's growth can be made using this recipe:

1. Mix two quarts of warm water with 1/2 a teaspoon of castile or another mild liquid soap.
2. While stirring, slowly add 3 teaspoons of pure neem oil to the mixture
3. Pour into a spray bottle and use to spray your plants and the garden's soil.

5.   Traps

Traps can serve as a quick way to bring down the number of grasshoppers, especially in a home garden or smaller farm. Set up a clear pane of glass vertically that the grasshoppers fly into, and then they fall down into a container of soapy water below which they sink and die in.⁶ Some people have found success making a trap for their home garden/yard by cutting the top off a drink bottle and inverting the top in the bottle (reinsert the top, upside down). Put some grass in the bottle, and grasshoppers will crawl in through the bottle top opening but not be able get back out.

If you have grasshoppers inside your home or building, sticky traps can be purchased that use a glue to trap grasshoppers, crickets and other insects. These are non-toxic, however they aren't made for use outdoors.

6.    Nosema Locustae Bait

If you have a larger grasshopper problem that occurs over more than one growing season, you might want to try a biological control. Nosema locustae is a protozoan that is used in commercial grasshopper baits such as Nolo Bait and Semaspore,^1,7 which are certified for use in organic production. This bait needs to be applied early in the season ideally near where grasshoppers eggs are located, so when the nymphs emerge in the spring they are infected with the bait which gives them a debilitating disease.⁷ There are definitely limitations to this natural bait: it can take significant time for it to affect grasshoppers, it is only effective on nymphs, and it doesn't work on some grasshopper species.^1,2,7 But as part of a larger grasshopper management plan, it can be an effective tool to use along with other strategies. 

Other methods that are touted by some home gardeners that you might want to try: garlic spray, hot pepper spray, kaolin clay, sprinkling boric acid around the edge of your garden, and sprinkling diatomaceous earth or all-purpose flour on your plants. Please let us know if you try a method that seems particularly effective!

More About Grasshoppers

Biology and Life Cycle

There are more than 100 species of grasshoppers in the Pacific Northwest, although most don't damage crops⁴ and can be managed if they are found in small numbers. The redlegged grasshopper⁴ and migratory grasshopper⁷ are two of the most common and damaging species in the Northwest, and across the U.S. After female grasshoppers lay their eggs in the fall, the eggs hatch in spring.³ They lay pods in the soil which can contain anywhere from 20 to more than 100 eggs.²

The new grasshoppers, called nymphs, begin rapidly feeding on a variety of plants.⁷ The nymph stage is when grasshoppers feed the most, so this is the best time to deal with them so that they don't continue to harm plants.⁷ Nymphs usually develop through five or six stages of molting which takes several weeks,^1,3 and then the adults can live two to three months until either the weather becomes too cold or food runs out.² Grasshoppers have one generation per year.³

Damage

Grasshoppers can be very destructive to crops and other plants, especially during the nymph stage when they feed and grow rapidly, and during outbreak years. With their chewing mouthparts they can defoliate a tree, damage fruit, and even devour entire plants.^2,4 But as mentioned earlier, during "normal" times (not during grasshopper outbreaks) they prefer to feed on young, green plants.  

Major outbreaks of large numbers of grasshoppers usually happen every 7 to 10 years, after a period when populations have slowly increased over time.⁴ Conditions that are ripe for a grasshopper outbreak include having a warm and dry spring, and when natural predators and grasshopper diseases are low.⁴ In the Northwest, the land east of the Cascades range is more likely to experience grasshopper outbreaks.³ In the summer of 2009, a grasshopper outbreak devoured 7,000 acres of grass meant for cattle in southeastern Oregon's high desert.⁸

Learn more from this Xerces Society article, "Home on the Range: Grasshoppers and Insecticides on Western Rangelands"

For expert advice tailored to your pest or weed issues, check out our sliding scale Pest and Weed Management Consultation services.

References

1. Cranshaw WS, Hammon R. Grasshopper control in gardens and small acreages–5.536 [Internet]. Fort Collins (CO): Colorado State University Extension; 2013 Jan [cited 2021 Mar 4]. Available from: https://extension.colostate.edu/topic-areas/insects/grasshopper-control-in-gardens-small-acreages-5-536/
2. Flint ML. Pest notes: Grasshoppers, publication 74103 [Internet]. University of California Statewide IPM Program; 2013 June [cited 2021 Mar 4]. Available from: http://ipm.ucanr.edu/PMG/PESTNOTES/pn74103.html#MANAGEMENT
3. Hollingsworth CS. (Ed.). Landscape pests- grasshopper [Internet]. In: Pacific Northwest Insect Management Handbook.
   Oregon State University; 2021 [cited 2021 Mar 4]. Available from: https://pnwhandbooks.org/insect/hort/landscape/common/landscape-grasshopper
4. Hoyt SC, Mayer DF. Grasshoppers [Internet]. Washington State University; WSU Comprehensive Tree Fruit Site; 1993 [cited 2021 Mar 4]. Available from: http://treefruit.wsu.edu/crop-protection/opm/grasshoppers/
5. National Research Council (U.S.), Panel on Neem. Effects on insects. In: Neem: a tree for solving global problems. Washington (DC): National Academies Press (U.S.); 1992. Available from: https://www.ncbi.nlm.nih.gov/books/NBK234642/
6. Elstein D. Catching grasshoppers the old-fashioned way [Internet]. USDA Agricultural Research Service; 2002 Apr 26 [cited 2021 Mar 8]. Available from: https://www.ars.usda.gov/news-events/news/research-news/2002/catching-grasshoppers-the-old-fashioned-way/
7. Willmore C, Thomas J, Hines S. Grasshopper management in the Pacific Northwest, BUL 972 [Internet]. Moscow (ID): University of Idaho Extension; 2020 July [cited 2021 Mar 4]. Available from: https://www.extension.uidaho.edu/publishing/html/BUL972-Grasshopper-Management-in-the-Pacific-Northwest.aspx#Control
8. Cockle R. Swarms of grasshoppers predicted to plague the West this year [Internet]. The Oregonian. 2010 May 11 [cited 2021 Mar 4]. Available from: https://www.oregonlive.com/news/2010/05/swarms_of_grasshoppers_predict.html