How to Identify Slug or Snail Damage

“What’s eating my plants?”

That’s the call we got one spring morning after our young friend Marcie ventured out to check her garden. The sun was shining, dew sparkled on the grass and all was right with the world. Everything, that is, except her row of new lettuce seedlings. Last week they had looked so promising – little green gems that were sprouting new leaves and growing vigorously despite the rainy weather. Now, instead of tender shoots ready for thinning, Marcie saw that some plants were completely gone! Others had ragged leaves full of holes or had bites missing around the edges. What was going on?

Marcie was new to growing but any gardener or homeowner in a damp climate has probably experienced the damage caused by slugs and snails. These pests do most of their damage at night and on wet, cloudy days. They are most active throughout the spring, early summer and again after autumn rains begin. In warm and wet climates slugs and snails can be active all year. During the day they hide in dark, moist sites under decaying leaves, low growing plants, dirt clods, pots or debris. Slugs are also quite capable of burrowing into the soil by following decayed plant roots, cracks, worm tunnels and along boards surrounding raised beds. These pests are also excellent climbers and can be seen quite high in plants. Snails in particular can seriously damage citrus trees.

 What Does Slug Damage Look Like?

  • Large, ragged holes in tender leaves and flowers.
  • Damage during the spring before many insects are active.
  • Traces of silvery slime on chewed leaves or along the ground.
  • Seedling leaves completely gone with only a small stem remaining.
  • Holes in hostas, lettuce, asparagus, the flowers of spring bulbs and many other plants.
  • Tiny scalloped edges like the photo below. Large slugs can quickly devour a leaf by taking row after row of small bites.


How to Confirm Slug or Snail Damage

Since our slimey friends most often do their work at night and hide during the day it can be difficult to know what’s going on. Look for the signs above, visit the garden in the early morning or grab a flashlight and check your plants at night. Confirm the presence of snails or slugs by setting out a few beer traps.

What You Can Do

There’s no magic wand to make slugs or snails disappear but by following this simple plan you can greatly reduce their damage.