What to do now
Mildest step first.
- Go out with a flashlight about 2 hours after dark and look at the seedlings and the soil around them.
- Hand-pick what you find, and dig gently around any cut-off stem for a curled gray or brown caterpillar.
- Lay boards or rolled-up newspaper between the rows in the evening and empty them in the morning; push a collar around each new transplant at least 1 inch into the soil.
- If whole seedlings vanish with clean, angled cuts, put up a 2-foot fence of mesh no larger than 1 inch, buried a few inches.
Look after dark
Most of the animals that eat seedlings overnight hide by day, so the quickest way to find out is to look while they feed. Oregon State suggests going out about 2 hours after sunset, or early in the morning, with a flashlight or headlamp, and UC suggests a flashlight check after dark for slugs, cutworms and earwigs alike. Look closely at the damage too. The shape of the bite, what's left behind, and whether the whole plant is gone each narrow the list.
Slugs and snails
Slugs and snails chew irregular holes with smooth edges and can eat young seedlings completely, as Clemson notes; the giveaway is the silvery slime trail on leaves and soil. UC IPM notes they are most active at night and on cloudy or foggy days, and Oregon State that they feed when it's above 50°F, calm and humid. Start by hand-picking at night, daily at first and then weekly. UC IPM suggests boards about 12 by 15 inches raised on 1-inch runners as a daytime hiding place you can check each morning, and beer traps sunk to ground level, which draw slugs from only a few feet away. Water in the morning, not the evening, so the ground dries before dark, and clear mulch and leaf litter from right around the seedlings. Copper bands work until they tarnish. If you use bait, iron phosphate is less harmful to pets and wildlife than metaldehyde, which is particularly poisonous to dogs and cats, though Oregon State cautions that all slug baits can be toxic to children and pets.
Cutworms
Cutworms clip seedling stems near or slightly below the soil line, so you find the top lying beside a stub, or the plant gone. UC IPM describes dull brown caterpillars 1 to 2 inches long that curl into a C when disturbed and spend the day on or slightly below the soil surface. Search the base of freshly cut plants and the top layer of soil with a flashlight at night, as UNH suggests, or dig gently around the stub; Virginia Tech notes they hide in shallow burrows by day. A collar around each transplant stops them. Virginia Tech suggests a stiff cardboard collar reaching 1 inch above the soil and 2 inches below, with a half-inch gap around the stem, while UNH suggests at least an inch below and two above. Keeping the garden free of weeds over winter and in early spring, as UC IPM and Virginia Tech suggest, leaves them less to live on before you plant.
Earwigs
Earwigs hide in dark, damp places by day and come out at night. UC IPM notes that damaged seedlings may be missing all or part of their leaves and stem, while older leaves get irregular holes or chewed edges. To tell their damage from slugs, check for slime trails, and look at night. Rolled-up newspaper, corrugated cardboard or a short piece of hose set out in the evening collects them by morning, and a shallow can with half an inch of oil traps them too. Earwigs also eat aphids, and Colorado State notes they may be considered beneficial overall, so trap them where they are hurting seedlings rather than everywhere.
Pill bugs and sowbugs
Pill bugs, which roll into a ball, and sowbugs, which can't, mostly eat decaying plant material. UC IPM notes they occasionally feed on seedlings, new roots and lower leaves, and Utah State that they are most active at night when humidity is high. Because their main food is dead plant matter, rule out slugs, earwigs and cutworms before blaming them. Where they are a problem, UC IPM suggests keeping the soil surface drier, using drip irrigation, and around young plants, raised beds and plastic mulch instead of organic mulch.
Rabbits
Rabbits leave a clean, angled cut, which UC IPM calls a characteristic diagonal 45° cut, and often take whole seedlings. Look for coarse, round droppings about 1/4 inch across. UC IPM notes that they start feeding in the evening and continue through the night into early morning. A fence is the dependable fix. University of Maryland suggests 2-foot chicken wire buried a few inches, and UC IPM notes that cottontails won't jump a 2-foot fence, that the mesh should be no larger than 1 inch, and that burying the bottom 6 to 10 inches stops rabbits that dig. Repellents usually fail in a vegetable garden, UC IPM adds.
Other culprits
A few others are worth ruling out. Voles are active day and night and leave surface runways between burrow openings; UC IPM suggests a barrier of 1/4-inch mesh at least 12 inches high, buried 6 to 10 inches. Deer leave ragged, torn edges rather than clean cuts, along with hoofprints 2 to 3 inches long, and feed late in the evening and very early in the morning. Tiny pits and shotholes 1/16 to 1/8 inch across are flea beetles, small insects that jump like fleas; Utah State notes young seedlings are the most sensitive. And if peas and beans disappear as seeds or tiny seedlings, birds may be the cause. Penn State Master Gardeners note that fabric covers keep birds from eating seeds and young seedlings, especially peas and beans.
Read the whole label first: it must list your crop, and its directions (amount, timing, gear, bees, days before harvest) are the law. If this page and the label differ, follow the label.
- LettuceA cool-season leaf crop that thrives in spring and fall, sulks in summer heat.
- Green BeanA warm-season legume that keeps coming as long as you keep picking.
- PeaA cool-season crop that rewards early sowing and quits when summer arrives.
- CabbageA long-maturing head that splits if you water it wrong at the wrong time.
- KaleThe cold-weather workhorse that improves when everything else quits.
- SlugIrregular holes in low-growing plants overnight, with silver slime trails left behind on leaves and soil.
- CutwormTransplants severed at the soil line overnight; fat gray caterpillars curl in the soil beneath.
- EarwigOvernight holes in petals, seedlings, and soft leaves — earwigs shelter by day and feed at night.
- Eastern Cottontail RabbitStems clipped cleanly at a 45-degree angle near soil level, with small round droppings nearby.
- Flea BeetlePinhole shothole damage across leaves with tiny jumping beetles that scatter when touched.