In the early weeks after planting, a gardener who starts plants from seeds or sets out young transplants has few enemies as destructive as slugs and snails. These small critters may appear harmless, but they are voracious eaters in the garden.
Slugs and snails usually inflict their damage during the night hours, cutting small plants down to just stalks, completely obliterating seedlings and leaving a trail of eaten leaves on larger plants. But the good news is there are a variety of defenses against these nasty little beasts.
Diatomaceous earth is comprised of the skeletal remains of microscopic creatures. Diatomaceous earth is a popular insect deterrent among organic growers and works on a variety of pests, including slugs and snails. The skeletal remains in diatomaceous earth act as tiny razor blades that lacerate the slugs and snails as they pass over. This is unpleasant for them and, in most cases, the slugs or snails find another place to get their lunches. Diatomaceous earth can be sprinkled around the perimeter of the garden or around each individual plant to create a barrier of protection.
Like diatomaceous earth, crushed eggshells act as jagged razor blades that cut open the slugs or snails as they crawl over and cause death by dehydration. Growers can place crushed eggshells around the perimeter of the garden or in each planting container. Along with keeping slugs and snails away, the crushed eggshells are a beneficial, slow-release source of calcium for the garden.
Copper is a great defense against slugs and snails and is commonly used in liquid slug and snail pesticides. Physical copper strips can be cut and placed around the base of each plant or around the entire garden as an obstruction for slugs or snails to crawl over. A grower can also cut thin strips of copper to wrap around the base of planting containers to create a fence. The copper fence will act as a deterrent or will kill the few brave slugs or snails that attempt to climb it.
One simple way a grower can deter slugs and snails in the garden is by changing the watering schedule. Slugs and snails are most active at night and need moisture to efficiently move around and feed. By watering early in the day, a grower can minimize any excess moisture during the night, which will limit the activity of slugs and snails. Horticulturists using planting containers can water the plants from the bottom to minimize the moisture in the soil around the base of the plant. This makes it difficult for the slugs or snails to reach the plants in the first place.
Believe it or not, this popular beverage for humans works great for catching slugs. Slugs love beer. In fact, slugs are so attracted to beer that they will drown themselves in it. Growers can attract the slugs by burying a jar containing a little beer in the soil. A slightly larger lid from another container can be propped above the jar to umbrella the jar from rain. Slugs are attracted to the beer and will dive right in, drowning themselves in the process. The grower can empty the dead slugs as needed and then refill the jar with fresh beer to reset the trap.
A great and inexpensive defense against snails is sand. Snails do not like to cross sand. As with diatomaceous earth and egg shells, a barrier of sand can be placed around the plants to deter any snails from entering the garden. The sand should be spread at least ¼-in. high and a fine-grade sand seems to work the best.
Another inexpensive way to deter slugs and snails is coffee grounds. A grower can spread a thin layer of coffee grounds around the perimeter of the garden or around any susceptible plants. The coffee grounds will dry out in the sun and create a rough surface to crawl over, deterring slugs and snails. It is also thought that the caffeine in the coffee works as a deterrent. Coffee grounds should be used sparingly as they could have adverse effects on young plants if too much is applied.
Once a gardener has experienced the devastation that slugs and snails can inflict on an otherwise healthy garden, he or she will do anything to protect the plants from the destruction of these treacherous mollusks. Implementing preventative measures to stop slugs and snails are the keys to ensuring a garden gets a good start in the spring time and then continues to grow vigorously.