What Is Eating My Rhubarb Leaves

If you’ve noticed holes, ragged edges, or a lace-like appearance on your rhubarb plants, you’re probably wondering what is eating my rhubarb leaves. Identifying the culprit is the first step to protecting your crop, as several common garden pests find rhubarb foliage quite tasty.

While the stalks are the prize for our pies and crumbles, the large leaves are a beacon for insects and slugs. Don’t worry, though—most of these pests can be managed with simple, effective strategies. Let’s look at the most likely suspects and how to deal with them.

This damage typically falls into a few categories: large irregular holes, small shot-like holes, skeletonized leaves, or completely missing seedlings. By examining the clues, you can pinpoint the problem.

Common Culprits and Their Telltale Signs

Here are the pests most often responsible for damaging rhubarb leaves in home gardens.

Slugs and Snails

These are the most frequent offenders. They feed at night and in damp weather, leaving large, irregular holes with smooth edges. You’ll often see their shiny slime trails on the leaves or soil around the plant.

Look for: Large chewed sections, slime trails, damage worsens after rain.
They often: Hide under boards, debris, or the dense rhubarb crown during the day.

Japanese Beetles

These metallic green-and-copper beetles are voracious. They skeletonize leaves, eating the tissue between the veins so that only a lace-like framework remains.

Look for: Groups of beetles feeding together in sunny weather, leaves reduced to “skeletons.”
They often: Appear in mid-summer and can quickly defoliate a plant.

Caterpillars (Various Types)

Several moth and butterfly larvae enjoy rhubarb. This includes cabbage loopers, imported cabbageworms, and sometimes even tomato hornworms.

Look for: Large, ragged holes or entire sections of leaf missing. Greenish fecal pellets (frass) on leaves are a clear sign.
They often: Hide on the undersides of leaves during the day.

Flea Beetles

These tiny, jumping beetles create a distinctive “shot-hole” pattern, especially on young rhubarb plants or new growth.

Look for: Dozens of small, round holes that make the leaf look like it’s been peppered with fine buckshot.
They often: Be most active in spring and jump quickly when disturbed.

Two-Spotted Spider Mites

These are nearly microscopic pests that suck plant juices. Damage appears as a fine stippling or yellowing on the leaf surface, which may eventually turn brown and dry.

Look for: Fine webbing on the undersides of leaves, especially in hot, dry conditions. Leaves may look dusty or dull.
They often: Thrive in crowded, drought-stressed plants.

How to Inspect Your Rhubarb Plants

Finding the pest is key. Follow these steps for a thorough inspection.

Check at the right time: Examine plants early in the morning or at dusk, when many pests are most active.
Look under leaves: Turn leaves over carefully. Most insects lay eggs and feed from the protected underside.
Inspect the soil: Look for cutworms, slugs, or holes near the base of the stalks.
Shake the plant: Hold a white piece of paper under a leaf and gently shake it. Dislodged mites or small beetles will be easier to see against the white background.
Monitor over time: Check your plants every few days to catch new infestations early, when they are easiest to control.

Effective, Garden-Friendly Control Methods

Once you’ve identified the pest, choose a targeted control. Always start with the least toxic option.

For Slugs and Snails:

Handpick them at night with a flashlight and drop them into soapy water.
Set traps like shallow dishes of beer sunk into the soil near the plants.
Create barriers with diatomaceous earth (reapply after rain) or crushed eggshells around the plant base.
Encourage natural predators like birds, frogs, and ground beetles.

For Japanese Beetles and Large Caterpillars:

Handpick beetles early in the morning when they are sluggish and drop them into soapy water.
Use floating row covers as a physical barrier, especially for caterpillars.
Apply neem oil or spinosad-based organic insecticides, which are effective against many chewing insects. Always follow the label instructions carefully.
For severe infestations, you may need to use a product containing pyrethrin, but be cautious as it can harm beneficial insects too.

For Flea Beetles and Spider Mites:

Use floating row covers to protect young plants from flea beetles.
For mites, a strong blast of water from the hose to the leaf undersides can dislodge them and reduce populations significantly.
Insecticidal soap sprays are very effective against both these pests when applied directly to them. You’ll need to cover the undersides of leaves thoroughly.
Ensure plants are well-watered and not stressed, as healthy plants can better tolerate minor feeding.

Prevention is the Best Long-Term Strategy

Keeping pests at bay is easier than fighting a full-blown infestation. Integrate these habits into your garden routine.

Keep the garden clean: Remove plant debris in the fall where pests can overwinter. Clear away weeds that can harbor insects.
Practice crop rotation: Avoid planting rhubarb in the same spot year after year if you can, though its a perennial so this is harder. Just be extra vigilant.
Water wisely: Water at the soil level, not overhead, to keep leaves dry and less inviting to slugs and fungal diseases.
Encourage beneficial insects: Plant flowers like dill, yarrow, and cosmos to attract ladybugs, lacewings, and parasitic wasps that prey on pests.
Choose resistant varieties: While mainly for stalk color/taste, some rhubarb varieties may show better pest tolerance. Ask at your local nursery.

A Note on Rhubarb Leaf Safety

Remember, rhubarb leaves themselves are toxic to humans and pets due to high levels of oxalic acid. This is why we only eat the stalks. This toxicity, however, does not deter most garden pests. Always wash harvested stalks thoroughly, especially if you’ve applied any treatment to the leaves.

When to Take Action and When to Relax

A few holes in your rhubarb leaves are usually not a cause for alarm. A healthy, established rhubarb plant can withstand a fair amount of leaf damage without affecting stalk production. The plants are remarkably resilient.

Focus your control efforts on severe infestations that threaten to defoliate the plant, or on very young plants that need their leaves to grow strong. Often, natural predators will bring the pest population into balance if you give them a chance.

FAQ

Are holes in rhubarb leaves harmful to the stalks?

Minor leaf damage rarely affects the edibility or growth of the stalks. The plant uses its leaves for photosynthesis, so severe, repeated defoliation can weaken the plant over time and reduce next year’s yield. But the stalks from a plant with holey leaves are still perfectly safe to eat after washing.

Can I use chemical pesticides on my rhubarb?

It is not generally recommended. Rhubarb is a food crop, and pesticides can leave residues. Always prefer organic, targeted methods first. If you must use a chemical, choose one labeled for use on edible crops and follow the pre-harvest interval (the waiting time between spraying and harvesting) exactly.

What’s eating just the edges of my rhubarb leaves?

This is often a sign of slugs or snails, who may start feeding from the leaf edge. Also, adult weevils sometimes notch leaf edges. Check for slime trails or inspect the plant at night with a flashlight to confirm.

Why are my rhubarb leaves turning yellow with holes?

Yellowing combined with holes suggests two issues. The holes are from a chewing pest (like beetles or caterpillars). The yellowing could be from a separate problem like overwatering, nutrient deficiency, or spider mite damage (which causes stippling and yellowing). Inspect the undersides of leaves for mites.

Do rabbits or deer eat rhubarb leaves?

Usually, no. The toxic oxalic acid in the leaves typicaly deters mammals like rabbits and deer. They might take a curious nibble but rarely cause significant damage. Your problem is almost certainly insects or slugs.

Figuring out what is eating your rhubarb leaves is a common garden puzzle. By taking a close look at the damage and the plant itself, you can usually identify the pest within a few minutes. Start with gentle, physical controls like handpicking or spraying with water. With a little observation and these targeted strategies, you can protect your rhubarb patch and ensure a hearty harvest of those tart, delicious stalks for seasons to come.