What are snails?
Snails and slugs are a common nuisance in many gardens and plant collections. They will eat many different plants, chewing straight through tender leaves and causing significant holes. Indoor plants are mostly safe from snails but they can appear in plant cabinets and other growing spaces with high humidity.
Symptoms
Snails and slugs mainly harm the leaves of your plants, leaving large holes where they have fed on the plant.
They often leave a trail of mucus where they've been. When it dires, it can turn a silvery color.
They can be found on the undersides of leaves, on the stems, in the soil or under the pot. They tend to like finding dark, humid places to hide during the day.
What to do now
The easiest and fastest way is to regularly manually remove the slugs and place them somewhere else
You can deliberately create a hiding spot in a shady area near your pots or garden beds. For example, use an upside-down bucket or pot propped up with a stone to leave a small entry gap, or use a roof tile. Keep the inside moist. As they gather there during the day to escape the heat, it becomes much easier to collect and dispose of them. While the hiding place is set up, be sure to check it daily
Make sure to also check for hidden snails in other places nearby. Look in dark, tight spaces like in and under buckets or around your pots.
Try to allow for good air circulation between your plants and avoid crowding them together
In more serious cases
There are different types of bio control in for of bacteria or nematodes you can use to control the population
If this doesn't work you can always use traps, barriers or repellents that are specialized for keeping snails away.
As a last resort, there are a number of pesticides (molluscicides) you could use. Unfortunately many of these are known to also be harmful to other wildlife, so use with caution.
Common questions
Are my indoor plants at risk?
If you keep your plants indoors all year round, slugs and snails shouldn’t be a problem for you in the long run. some slugs or snails might hitchhike with a pot, but won't reproduce well in regular indoor conditions. If you have plants outside at any point, you also run the risk of getting them on your plant or bringing them in on the pot. Because they’re not picky about what types of plants they feed on, it’s a good idea to keep an eye on all of your outdoor plants for damage.
What do they look like?
Snails and slugs are types of mollusks, meaning that they do not have internal skeletons. However, snails are protected by (and are easily identified by) their shells. Both can cause a fair amount of damage to your plants.
How long do they live?
Most common land snails live for around 1-3 years, however, they are known to live much longer in captivity, and their lifespan varies depending on the type of snail.
What do they eat?
Snails feed on the leaves and tender parts of plants. Young snails begin feeding immediately. However, they do seem to usually avoid plants with strong-smelling foliage, or those that have waxy or hairy coverings.
Can I prevent this in the future?
Try to water your plants in the morning so that they have the chance to dry out properly before snails become active in the evening/night if growing outdoors.