Grasshoppers Eating Your Plants? A Beginner's Control Guide

The Sudden Devastation of Grasshopper Infestations

Watching grasshoppers eating your prized garden plants is one of the most frustrating experiences for a home gardener. Unlike aphids or spider mites that slowly drain plant vigor, grasshoppers are voracious, mechanical chewers that can strip a vegetable bed or ornamental border down to the stems in a matter of hours. A single adult grasshopper can consume up to 50% of its body weight every single day. When local populations surge due to hot, dry spring conditions, the resulting swarm can cause catastrophic landscape damage.

For beginners, the sheer speed of the destruction can feel overwhelming. However, effective grasshopper management does not require harsh, broad-spectrum chemical pesticides. By understanding their dietary preferences, recognizing the early signs of damage, and deploying targeted biological and physical controls, you can protect your yard. This guide breaks down exactly what these pests target and provides actionable, budget-friendly strategies to stop them.

The Grasshopper Diet: What Exactly Are They Eating?

Grasshoppers are generalist herbivores, but they are far from indiscriminate. They show distinct preferences for certain plant families while actively avoiding others. According to University of Minnesota Extension, grasshoppers are highly attracted to tender, broadleaf plants and specific grasses, especially when those plants are stressed by drought.

Highly Preferred Target Plants

• Vegetables: Lettuce, beans, corn, carrots, and onions are primary targets. They will also heavily defoliate young tomato and pepper plants.
• Ornamentals: Hostas, daylilies, asters, and sunflowers are frequently decimated.
• Annual Flowers: Zinnias, marigolds (despite some claims of resistance, certain varieties are heavily eaten), and cosmos.

Plants Grasshoppers Tend to Avoid

• Herbs: Cilantro, rosemary, sage, lavender, and mint contain essential oils that deter chewing insects.
• Ornamentals: Horehound, calendula, dianthus, and creeping zinnia.
• Squashes and Cucurbits: While they may nibble on young vines, mature cucurbit leaves are generally too rough and hairy for their preference.

Identifying Grasshopper Damage vs. Other Pests

Before applying any treatment, confirm that grasshoppers are actually the culprits. Beginners often confuse grasshopper damage with that of caterpillars or Japanese beetles. Use the comparison matrix below to accurately diagnose the pest eating your foliage.

Pest	Leaf Damage Pattern	Visible Evidence Left Behind	Time of Day Active
Grasshoppers	Large, irregular, jagged chunks missing from leaf edges or centers; stems entirely severed on young plants.	Large, cylindrical, dry frass (droppings) on the soil; no webbing or slime trails.	Mid-morning to late afternoon (need sun to warm up).
Caterpillars	Skeletonized leaves (veins left intact) or large smooth-edged holes; rolled or webbed leaves.	Sticky webbing, silk threads, and moist, irregularly shaped frass.	Often nocturnal or early morning.
Japanese Beetles	Severe skeletonization; leaves look like delicate lace with only the vein network remaining.	Beetles clustering in groups on the foliage; small, hard droppings.	Warm, sunny afternoons.

4 Beginner-Friendly Ways to Stop the Damage

Once you have confirmed that grasshoppers are eating your garden, immediate intervention is required. The following methods are safe for home use, protect beneficial pollinators, and are highly effective when applied correctly.

1. Biological Control: Nosema locustae (Nolo Bait)

For large yards or severe infestations, chemical sprays are inefficient and harmful to bees. Instead, use a biological bait containing Nosema locustae, a naturally occurring microsporidian parasite that specifically targets grasshoppers and crickets. Products like Nolo Bait or Semper Organics Grasshopper Bait are wheat bran coated with these spores.

How it works: Nymphs eat the bait, the spores multiply in their gut, and the insects become lethargic and stop feeding within 24 hours. They die within a few weeks. Because grasshoppers are cannibalistic, healthy insects eat the infected corpses, spreading the spores through the population.

Application Specifics: Apply at a rate of 1 pound per acre (or about 1 tablespoon per 10 square feet in garden beds). Cost is typically $35 to $45 for a 5-pound bag. Critical timing: This only works on young nymphs (1/4 to 1/2 inch long), not large adults. Apply in early summer when nymphs first emerge from hatching beds.

2. Physical Barriers: Floating Row Covers

If you are growing high-value vegetables like lettuce or bush beans, physical exclusion is the only 100% fail-safe method. Lightweight, spunbonded polypropylene fabrics, such as Agribon AG-19 or AG-30, create a physical wall that grasshoppers cannot chew through.

Application Specifics: Drape the fabric over the plants and secure the edges with landscape staples or soil mounds. AG-19 allows 85% light transmission and provides a few degrees of frost protection, making it ideal for spring planting. A 100-foot roll costs between $18 and $25. Remove the covers only when plants are large enough to withstand minor nibbling or when they require insect pollination (like squash).

3. Botanical Repellents: Cold-Pressed Neem Oil

For ornamental beds where row covers are aesthetically unpleasing, use a cold-pressed Neem Oil spray. Ensure you purchase a product with a high azadirachtin content (such as Bonide Neem Oil Fungicide Miticide Insecticide, Model 708). Azadirachtin acts as an antifeedant—it makes the plant tissue taste so bitter that the grasshoppers stop eating and move on.

Application Specifics: Mix 1 fluid ounce of neem oil per gallon of water with a few drops of mild liquid dish soap as an emulsifier. Spray all leaf surfaces thoroughly, including the undersides. Reapply every 5 to 7 days, or immediately after rainfall. Cost is roughly $15 to $20 for a 16-ounce concentrate bottle. Warning: Only spray in the early evening to avoid leaf burn from the sun and to minimize contact with foraging bees.

4. Natural Predators: Backyard Poultry

If local zoning permits, integrating chickens, guinea fowl, or Muscovy ducks into your landscape is the ultimate long-term grasshopper control. Poultry are aggressive foragers and will actively hunt down adult grasshoppers and scratch up the soil to eat overwintering egg pods. Guinea fowl are particularly renowned for their tick and grasshopper consumption, though they are notably louder than chickens.

Companion Planting: Creating a Deterrent Perimeter

While no plant is 100% grasshopper-proof under extreme swarm conditions, establishing a perimeter of highly aromatic, tough-leaved plants can significantly reduce the migration of grasshoppers into your vulnerable vegetable beds. According to integrated pest management guidelines cited by the Old Farmer's Almanac, grasshoppers rely heavily on their antennae to detect plant volatiles. Strong-smelling herbs mask the scent of their preferred crops.

Recommended Perimeter Plants:

• Cilantro/Coriander: Plant thick borders of cilantro around your lettuce beds. Grasshoppers despise the scent.
• Horehound: A perennial herb in the mint family that thrives in poor soil and actively repels chewing insects.
• Calendula: Acts as a mild deterrent while attracting beneficial predatory wasps that may prey on early-stage grasshopper nymphs.
• Sweet Clover: Plant this as a trap crop on the far edge of your property. Grasshoppers are highly attracted to it, drawing them away from your primary garden beds.

Frequently Asked Questions (FAQ)

Do grasshoppers bite humans or pets?

No. While large adult grasshoppers possess strong mandibles designed for shearing tough plant fibers, they do not seek out or bite humans, dogs, or cats. If you handle a large grasshopper roughly, it might nip at your skin in self-defense, but it rarely breaks the skin and is not venomous or toxic.

Will grasshoppers come back next year if I kill them all this summer?

Likely, yes. Female grasshoppers lay egg pods containing 15 to 20 eggs each in late summer and early fall. They prefer to deposit these pods in undisturbed, dry, compacted soil—such as ditch banks, fence lines, and weedy patches. These eggs overwinter and hatch the following spring. To reduce next year's population, till or rake the soil in these marginal areas in late fall or early spring to expose the egg pods to the elements and ground-foraging birds.

Are there any effective chemical sprays for home use?

Products containing bifenthrin or permethrin (like Spectracide Triazicide) will kill grasshoppers on contact. However, they are broad-spectrum neurotoxins that will also kill bees, butterflies, and beneficial predatory insects. Furthermore, because grasshoppers continuously migrate into yards from neighboring fields and wild areas, a chemical barrier degrades within a week, leaving you vulnerable to the next wave. Biological baits and physical barriers remain the superior choice for sustainable home garden management.