The brown garden snail (Cornu aspersum) eats irregular holes in leaves, flowers and fruit at night, and leaves shiny slime trails behind. Hand-picking, trapping and removing shelter work much as they do against slugs, and so does iron phosphate bait; that page covers them. Snails differ in three ways that matter. They climb, so on citrus and other trees a copper band round the trunk and a pruned-up skirt keep them off the canopy. The slug nematode sold in the UK is unlikely to reach them. In 12 California counties you can also release the predatory decollate snail, which eats young brown snails. It is slow, it is illegal to release elsewhere in California, and it must be kept away from native snails.
Cornu aspersum on a citrus trunk at dusk, with a slime trail below. Photo: pending.
The adult shell is 28–32 mm (1⅛–1¼ in) across, with four to five whorls. It is yellowish or horn-coloured with chestnut-brown spiral bands (University of Florida). UC IPM calls it the snail most often causing problems in California gardens, and says it was brought from France in the 1850s to be eaten. In Britain the RHS lists the common garden snail among the species most likely to be feeding on garden plants. It is one of about 90 snail species in the UK, most of which do no harm.
The snail most often confused with it is its predator. The decollate snail has a tall, narrow, cone-shaped shell, pinkish brown, with the tip broken off as it grows. UC IPM gives its length as up to about 40 mm (1⅗ in) and the University of Florida as up to 45 mm (1¾ in). Slugs do the same damage but have no external shell.
Snail damage looks the same as slug damage: irregular holes with smooth edges in leaves and flowers, and the shiny slime trail that confirms one or the other (UC IPM). Height is a clue. The brown garden snail climbs trees, fences and walls (UC IPM), and in California it damages the leaves and fruit of citrus trees (University of Florida), so chewing in a citrus canopy or on fruit still on the tree is often its work.
Snails are hermaphrodites, but they mate before laying. The brown garden snail grows far more slowly than a pest slug. It takes about two years to mature in southern California, against three to six months for slugs. It is most active at night and on cloudy or foggy days. In cold weather it hibernates in the topsoil. In hot, dry weather it estivates, sealing its shell with a parchment-like membrane, often on a trunk or wall. In mild coastal areas it stays active all year (UC IPM).
The brown garden snail eats most soft growth, and UF's host list runs across vegetables, cereals, flowers, fruit and ornamentals. The host that sets it apart from slugs is citrus. UC IPM calls citrus especially susceptible, and snails also feed on the young bark, leaves and fruit of some other trees. The other plants named here are shared with slugs, whose page lists them in full.
No numeric threshold for snails in home gardens was found in extension literature. What matters is what is at risk: UC IPM says snails are mainly pests of seedlings and soft, herbaceous plants, and of the young bark, leaves and fruit of some trees, citrus above all. UC IPM also says hand-picking can be very effective if done thoroughly: daily at first, then weekly once numbers have clearly fallen.
Water the area in the late afternoon to draw snails out, then check with a torch after dark (UC IPM). Look up as well as down: on trunks, in the canopy of citrus and on walls. By day, lay boards about 12 by 15 in raised on 1-in runners (UC IPM) and check under them each morning; inverted melon rinds also work. Count and remove what you find.
Snails have natural enemies, among them ground beetles, snakes, toads, turtles and wild birds (UC IPM). UC IPM says penned ducks, geese or chickens can reduce snail problems significantly. The biological control sold for snails is the predatory decollate snail, used in southern California citrus groves against young brown snails. UC IPM says it can give very effective control, but also that it is not consistently effective and may take 4–10 years to bring brown snails down to insignificant levels. It can be released legally only in Fresno, Imperial, Kern, Los Angeles, Madera, Orange, Riverside, Santa Barbara, San Bernardino, San Diego, Ventura and Tulare counties, and must be kept away from natural areas where it could eat endangered native snails. Snail bait kills it too. The slug nematode sold in the UK as Nemaslug is no help against snails. The RHS says snails rarely come into contact with the soil-dwelling nematodes.
Everything on the slugs page applies to snails too: hand-picking by torchlight, board traps, watering in the morning and removing daytime shelter. The same goes for iron phosphate bait if you use one. It is not repeated here. The steps below are the ones that are specific to snails, or matter more for them.
Rating: the effect on this pest's natural enemies if a spray hits them or they feed on treated plants. REI is the re-entry interval on farm and greenhouse labels; home labels usually give none, so follow the label.
UC IPM Pest Notes: Snails and Slugs, UC ANR Pub. 7427 (Wilen & Flint, updated 03/2018)
UC IPM Natural Enemies Gallery: Decollate Snail
Univ. of Florida Featured Creatures: Brown Garden Snail, Cornu aspersum (Dekle & Fasulo)
RHS Advice: Slugs and snails
Tip Top Bio-Control, Decollate Snails product page (release rates; accessed Sept 2026)
Drafted from the sources below, then checked claim by claim against those sources on 23 September 2026.
Suggest a correction →The same pest behaves differently on different hosts. Each page below gives the host-specific control, rate and threshold.