Do Grasshoppers Eat Trees: What Entomologists Confirm About Their Diet

Grasshoppers are specialized plant eaters with mandibles designed for soft vegetation, not woody structures. 🌿 Their diet prioritizes grasses and broadleaf plants because these provide the moisture and nutrients they need to thrive.

While they might gnaw on saplings or thin bark during droughts, trees remain safe because grasshoppers lack the jaw strength to penetrate mature wood. This dietary preference actually benefits gardeners—it's the young shoots of vegetables and flowers that typically suffer, not the trees themselves.

What's fascinating is how their feeding habits shift with seasons. In spring and summer, when fresh growth is abundant, grasshoppers focus on tender leaves. But during dry spells, they become more opportunistic, nibbling on whatever's available—including tree bark.

This behavior explains why some homeowners notice damage on young trees during particularly harsh summers, even though grasshoppers would never target a healthy oak as their primary food source.

Grasshopper diet: what they actually consume in gardens

Grasshoppers are built for soft, nutrient-rich plant matter—not trees. Their mandibles, powerful for their size, are designed to shear through delicate grass blades and broadleaf foliage, not chew through lignin-rich wood.

Studies show they prefer plants with high moisture content, like corn stalks (which can be stripped down to the stalk) or alfalfa leaves (up to 30% protein by dry weight), because these provide the energy they need for rapid growth and reproduction. 🌱 The key difference is in their jaw mechanics: grasshopper mandibles move in a scissor-like motion, perfect for cutting plant tissue but incapable of the crushing force needed to break down cellulose in mature wood.

Their diet also shifts dramatically with plant availability. During peak growing seasons, grasshoppers consume 10-20 times their body weight daily in fresh vegetation, focusing on grasses (especially cool-season varieties like fescue) and broadleaf plants.

But when drought stress reduces tender growth, they become generalists, nibbling on young tree bark or even dead plant material. This explains why you might spot grasshoppers on tree trunks during dry spells—they're not choosing trees, they're simply scraping at whatever's accessible.

The bark they consume is typically less than 1mm thick, making it more like eating paper than wood.

What makes trees safe from grasshopper damage is their bark's thickness and chemical composition. Mature trees have bark layers that can measure 5mm or more, while grasshopper mandibles are only capable of exerting 0.5-1.5 Newtons of force—enough to chew through thin bark but not enough to penetrate deeper.

The lignin and suberin in tree bark also contain natural repellents that deter grasshoppers, unlike the soft, palatable leaves they target. This is why entomologists classify grasshoppers as "folivores" (leaf-eaters) rather than bark or wood specialists.

Interestingly, their feeding patterns create a feedback loop in ecosystems. When grasshoppers overconsume grasses, they stimulate new growth by removing old leaves, which can actually benefit some tree species by reducing competition for sunlight and nutrients.

However, this benefit disappears when they target ornamental plants or crops—where their appetite becomes a nuisance. The 1930s Dust Bowl saw grasshopper swarms devour entire wheat fields, but even then, they avoided woody plants, focusing instead on the vulnerable crops that sustained human populations.

For gardeners, understanding this preference is crucial. Grasshoppers won't strip a tree bare, but they will skeletonize your rose bushes or devour your vegetable garden if left unchecked. Their mandibles can remove entire leaves in under 30 seconds, leaving behind a lace-like pattern that's unmistakable.

This is why entomologists recommend protecting high-value plants with row covers or neem oil sprays—while trees remain safe, the plants grasshoppers actually prefer will suffer without intervention.

Protecting trees from grasshopper damage in landscapes

While grasshoppers won't destroy your trees, they can still cause cosmetic damage—especially to young saplings or newly planted specimens. The key is to focus protection on high-risk areas where grasshoppers gather. Start by removing tall grasses and weeds near your trees, as these provide both food and shelter.

Keep mulch rings around tree bases clean and free of debris, since grasshoppers use leaf litter as hiding spots during the day. 🌳 I recommend maintaining a 3-foot radius of clear ground around each tree to disrupt their feeding patterns.

For extra defense, consider companion planting with grasshopper-repelling herbs. Marigolds, basil, and catnip release scents that deter these pests naturally, while also adding beauty to your landscape. Another effective strategy is to install chicken wire guards around young trees during peak grasshopper season (late summer through early fall).

These lightweight barriers prevent grasshoppers from climbing while still allowing water and air to reach the roots. For established trees, a simple spray of neem oil (mixed at 2 tablespoons per gallon of water) applied to the lower trunk and branches creates an unpleasant taste that grasshoppers avoid.

If you notice grasshoppers congregating on your trees during dry periods, act quickly to redirect their attention. Set up trap crops like sunflowers or corn at the edge of your property—these attract grasshoppers away from your trees while providing a more appealing food source.

You can also create a soapy water spray (1 tablespoon dish soap per gallon of water) for spot treatment on affected bark. Just be sure to apply it in the evening when grasshoppers are less active, as the soap disrupts their waxy outer coating.

The most important thing to remember is that grasshoppers target trees only when better options aren't available. By maintaining a healthy garden with diverse plantings, you'll naturally reduce their interest in your trees.

Focus your prevention efforts on vegetable gardens, ornamental flowers, and lawn edges—these are where grasshoppers will cause real damage if left unchecked. With these strategies, you can enjoy your trees knowing they're protected from these common garden pests.