What Plants Do Rats Eat? From Gardens to Landscapes

Rats eat an extraordinarily broad range of plant material, from ripe tomatoes in backyard gardens to the seeds and bark of forest trees across entire landscapes. The two species most people encounter, the brown rat and the black rat (also called the roof rat), are true omnivores, but plant matter often dominates their diet, especially when fruits, seeds, and vegetables are readily available. What they choose, and how much damage they do, depends on the season, what is growing nearby, and whether the rats are living alongside humans or foraging in wilder settings.

Garden Fruits and Crops

In a garden, nearly any fruit or vegetable is fair game. Rats will eat tomatoes, strawberries, squash, corn, peas, and root crops like carrots and sweet potatoes. Citrus is a particular favorite for roof rats, which are agile climbers. Oranges, lemons, and avocados are all commonly gnawed, sometimes while still on the tree. On Amami Oshima Island in southern Japan, roof rats have been documented stripping the bark of tankan orange trees, damaging the crop well beyond simply eating the fruit.¹ In home gardens, rats tend to go for whatever is soft and accessible first. Melons, berries, and stone fruits that have fallen to the ground are easy pickings, and rats will climb fences, trellises, and fruit trees to reach crops that have not yet dropped.

Herbs and leafy greens are lower priorities compared to energy-dense fruits and seeds, but rats will still nibble lettuce, basil, and other leafy plants, especially when water is scarce, since these leaves provide moisture. If you have noticed jagged holes in your tomatoes or half-eaten strawberries with small teeth marks, rats are a more likely culprit than most gardeners initially suspect, since the damage often gets blamed on birds or slugs.

Bark Stripping and Tree Damage

One of the more surprising forms of plant damage rats cause is bark stripping. This goes well beyond nibbling at fruit. Rats gnaw away patches of bark from tree trunks and branches, sometimes girdling a limb completely and killing it. The behavior is widespread across both hemispheres and is not limited to a single species. A broad review of bark consumption by rodents found that this feeding pattern tends to peak during environmental stress: under snow cover in northern climates and during dry seasons in regions with annually fluctuating rodent populations.² The authors pointed out that bark and inner stem tissue are a well-protected resource that rodents tap only in difficult conditions, when other food has become scarce.

For gardeners and orchardists, this matters most with young trees. A sapling or newly planted fruit tree with thin bark is far more vulnerable than a mature specimen. When bark is stripped in a ring around the trunk, nutrients and water can no longer travel between the roots and the canopy, and the tree dies above the ring. Wrapping the lower trunks of young trees with hardware cloth or metal guards is one of the simplest protections against this kind of damage.

Seeds on the Menu

Seeds are arguably the plant food rats interact with most, and the consequences stretch far beyond the garden. Rats eat seeds from grasses, weeds, shrubs, and trees. In agricultural settings, rodents are considered significant seed predators, and research suggests this seed consumption can function as a kind of natural weed control by depleting the “seed shadow” that weeds leave in fields.³ Lab experiments in that study found that voles preferred the seeds of common noxious weeds over the seeds of endangered native plants, raising the possibility that rodent seed predation could, in some contexts, favor native plant diversity rather than harm it. That said, the dynamic shifts in wilder landscapes where rats are invasive.

In tropical forests, seed predation by black rats is extensive. In Puerto Rico’s rain forests, black rats were responsible for about 65% of all recorded interactions with seeds placed on the forest floor, and roughly 29% of those interactions resulted in confirmed seed removal.⁴ Removal rates varied by plant species: one palm had only 9% of its seeds removed over 10 days, while other species saw more than 30% disappear. In disturbed forest gaps, where canopy openings let in more light and more new growth attempts to establish, seed removal was even higher for some species. The researchers concluded that rats are shaping what the forest looks like from the ground up, influencing which seedlings survive and which never get the chance.

Rats as Accidental Seed Dispersers

The relationship between rats and seeds is not purely destructive. Research in Hawaii found that many interactions between black rats and seeds of both native and non-native plants resulted in dispersal rather than total destruction.⁵ Rats carry seeds away from the parent plant, and some survive the trip. This dual role, predator and disperser, complicates the picture for conservationists: removing rats does not always produce a straightforward benefit for native plants, because the rats may have been spreading some of those same seeds.

Seeds can even survive passage through a rat’s gut and germinate afterward. In New Caledonian rain forests, researchers compared what happened to seeds eaten by native fruit-eating birds and bats versus those eaten by invasive rats. Seeds germinated after passing through rat digestive tracts, confirming that rats act as functional dispersers. However, rats were less efficient at it: more seeds were destroyed during gut passage in rats than in native frugivores, and the seeds that did survive took longer to germinate and had lower overall germination rates.⁶ Rats are a poor substitute for the animals that evolved alongside these plants, but they are not a total dead end for seed survival.

In at least one case, the effect is strikingly positive for the plant. On Mediterranean islands, ship rats eating the fleshy fruits of the invasive succulent Carpobrotus not only disperse the seeds but actually enhance their germination rate and speed after gut passage.⁷ This is a case of two invasive species cooperating: the rat spreads the invasive plant, and the plant feeds the rat. The term researchers use for this dynamic, “invasional meltdown,” captures how multiple introduced species can reinforce one another’s impacts on native ecosystems.

Seed Caching and Hoarding

Rats do not always eat seeds immediately. Many species cache seeds in burrows or scatter them across the landscape, and this hoarding behavior has real consequences for which plants establish and where. A study of Edward’s long-tailed rat found that hoarding strategy depended on both burrow availability and how long it took to handle a given seed. Seeds that were quick to process, like those of the oil-tea tree, were more likely to be eaten on the spot or scatter-hoarded in shallow surface caches. Seeds that took longer to handle, like those of a hardwood oak relative, were carried into underground burrows for larder-hoarding.⁸ Over 80% of the animals preferred underground burrows and stored significantly more seeds in them when both surface and underground options were available.

A global review of how rodents and related small mammals influence plant establishment found that larder-hoarded seeds, stored deep underground, rarely germinate successfully because the conditions inside a burrow are too dark and confined. Scatter-hoarded seeds, buried shallowly across the landscape, have a better shot. In fire-prone ecosystems, shallow caches can actually protect seeds from heat shock during burns, allowing them to germinate after the fire passes.⁹ Some seeds cached by rodents end up at precisely the right depth to survive a fire and sprout in the nutrient-rich ash afterward. For gardeners, hoarding behavior means that rats are not just eating your seeds. They are moving them, sometimes planting them in unexpected spots across the yard.

The Succulent Connection

Rats are drawn to fleshy, water-rich plant tissue, and this preference becomes especially pronounced in dry environments. Research on the bush Karoo rat in southern Africa documented how these animals collect succulent plants and bring them back to their lodge (a mound-like shelter). About 68% of the collected plant species were eaten fresh, and succulents that were not eaten immediately dried out into a material the researchers called “plantong.” Contrary to what you might expect, these dried stores were not saved for lean times; they were consumed within about six days on average.¹⁰ The plantong accumulated mostly during the wetter, food-rich season, not during scarcity, which suggests that the drying was incidental rather than a deliberate preservation strategy.

For gardeners in arid or semi-arid climates, this attraction to succulence explains why rats so often target irrigation lines, drip emitters, and the fleshy stems of ornamental succulents. Plants like aloe, agave, and prickly pear can all show gnaw marks, and the damage is sometimes misattributed to rabbits or other wildlife. The common thread is moisture: in a dry landscape, any plant tissue that holds water becomes more valuable to a rat.

What Happens When Rats Are Removed From an Ecosystem

Some of the most dramatic evidence for how much rats eat comes from studies that tracked what happened to plant communities after rats were eradicated from islands. On a tropical atoll in the Indian Ocean, researchers monitored seedling recruitment before and after a rat eradication campaign. For five of the six native tree species studied, seedling numbers increased after the rats were gone. The most striking case involved Pisonia grandis, a dominant canopy tree found across the Pacific region. Before eradication, no seedlings of this species were found at all. One month after the rats were removed, up to 688 individual Pisonia seedlings per 100 square meters appeared.¹¹ Two other locally rare native trees that had shown zero recruitment before eradication also began producing seedlings once rats were gone.

That said, the story is not always so clean. In French Polynesia, researchers examining the relationship between rats and endangered native plants concluded that while rats do suppress seedling recruitment and alter how vegetation develops over time, they are not usually the sole cause of plant extinctions. Most of the endangered species affected by rats in that region already lived in severely degraded habitats, damaged by logging, invasive plants, and other pressures. The researchers characterized rats as a “coup de grâce species,” delivering the final blow to plant populations that were already in deep trouble rather than single-handedly driving them extinct.¹² This framing matters because it means rat control alone will not save most threatened plant species if the underlying habitat degradation is not also addressed.

Plants That Rats Tend to Avoid

If rats eat such a wide range of plants, a natural question is whether any plants deter them. The answer is yes, though the effect is often modest rather than absolute. A systematic review of plant secondary metabolites as rodent repellents found that essential oils and terpenoids showed the strongest and most consistent repellent effects across multiple rodent species in laboratory experiments.¹³ These are the kinds of chemicals that give plants like mint, eucalyptus, and lavender their characteristic strong scents.

Laboratory testing of specific natural substances found that wintergreen oil, chili, peppermint oil, bergamot oil, and geranium oil all repelled rats, both individually and in combination. Rats exposed to these substances in a controlled arena spent significantly less time near them compared to untreated areas.¹⁴ Whether planting mint or geraniums around a garden bed translates into meaningful rat deterrence in the real world is a different question. The concentration of volatile oils in a living plant is much lower than what gets applied in a lab setting, and a hungry rat can learn to tolerate smells it initially avoids. Still, strongly aromatic herbs like rosemary, mint, and oregano are among the least likely plants in a garden to be directly consumed by rats, and interplanting them among more vulnerable crops is a low-cost strategy even if it is not a guarantee.

Capsaicin, the compound that makes chili peppers hot, is worth a special mention. Rats do perceive capsaicin as irritating and will avoid treated food when alternatives exist. Some commercial rodent deterrent products use capsaicin-based coatings. The limitation is durability: rain, irrigation, and sun break down capsaicin on plant surfaces quickly, so any protective effect requires frequent reapplication.

How Rats Decide What to Eat

Rats are neophobic, meaning they are wary of unfamiliar foods. A new plant appearing in a garden will usually not be attacked immediately. Instead, a rat takes a small taste, waits, and only returns for more if there are no ill effects. This cautious approach is part of what makes them so successful as a species, and it is also why poison baits need to be introduced carefully to be effective.

Beyond neophobia, rats appear to select plants partly based on how much effort is required versus the caloric or moisture reward. The hoarding research discussed earlier showed that seed handling time influenced whether rats consumed seeds immediately or cached them, and which hoarding strategy they used.⁸ In practical terms, this means rats gravitate toward the easiest meals. A soft tomato on the ground will be eaten before a hard-shelled nut. A fallen avocado will be preferred over bark. Bark and woody tissue, as the earlier research showed, tend to be resources of last resort, used mainly when preferred foods are unavailable.

Seasonal availability also drives choices. In spring and summer, when gardens and wild landscapes produce abundant fruit and fresh growth, rats eat more plant material overall. In winter, when fresh vegetation is scarce, they shift toward stored seeds, bark, and whatever else remains accessible. This seasonal flexibility is one reason rats thrive in such diverse environments, from tropical islands to temperate cities.

Practical Implications for Gardeners and Land Managers

Knowing what rats eat shapes how you protect against them. In a vegetable garden, the most vulnerable crops are soft fruits and ripe produce left at ground level. Harvesting promptly, clearing fallen fruit daily, and elevating beds where possible all reduce the food signal that attracts rats. Compost bins that include fruit scraps or vegetable waste should be enclosed in rodent-proof containers rather than open piles.

For orchards and landscape trees, protecting trunks with metal guards and removing lower branches that give roof rats easy climbing access can prevent bark damage. Pruning branches away from rooflines and fences eliminates the aerial highways roof rats use to move between trees and structures.

In larger landscape management, the evidence from island ecosystems shows that rats can suppress the regeneration of entire tree species, but also that rat removal alone may not restore plant communities unless other habitat damage is also repaired.¹² Conservation projects that combine rat control with invasive-plant removal and habitat restoration tend to see the strongest recovery in native seedling recruitment.¹¹

One frequently overlooked point: rats do not just eat the plants in your garden. They move seeds around. If you have been puzzled by volunteer seedlings of species you never planted appearing in odd corners of the yard, rat scatter-hoarding is a plausible explanation. Forgotten caches sprout when conditions are right. In wilder settings, this behavior can help maintain plant diversity in ecosystems that evolved with seed-caching rodents, and it can accelerate the spread of invasive plants in ecosystems that did not.