How to Protect Seedlings from Slugs and Snails

By Erin Marissa Russell

Seasoned gardeners know what a threat slugs and snails can present to a carefully tended garden, and a struggle against these mollusks when your plants are seedlings or new shoots can be especially damaging. Luckily, there are steps you can take to defend your young plants against slugs and snails early, while the plants are seedlings. Deploying a few of the strategies we’ve laid out in this article will prevent losing your vegetable plants, herbs, or flowers in the early stages and keep on working to protect your garden as the season wears on.

You can bypass the trouble of time-consuming and labor-intensive protective measures like starting plants indoors or in containers instead of directly sowing them into your prepared garden soil. Keep reading to learn what you can do today to ensure your prized young plants are protected from slugs and snails—while your seedlings are small and as your garden grows into a display of mature, blooming plants and productive food crops.

Quick Tips for Keeping Seedlings Safe from Slugs and Snails

In the next part of this article we present two strategies in detail to help you go on the offensive and really wipe out slugs in areas where young plants are growing. Before implementing either of those measures, though, arm yourself with what experienced gardeners have learned through centuries of trial and error. Here are some quick tips to help you prevent slugs and snails, or spot them if they do attempt to cross into your territory and trespass on your protected seedling nursery zone.

Wage your war on slugs and snails where it really matters. Almost all gardens will experience some level of damage from these mollusks. Use your time and energy to reinforce the most vulnerable members of the garden: seedlings and fresh new shoots.
Keep an eye out for slime trails, which can give you inside information about where snails and slugs are traveling in your garden. They look like lines drawn in quicksilver, and you’ll find them brushed across the leaves and stems of plants as well as traced along your garden’s walkways or other hard surfaces.
If you want to get really hands-on, just stay up late and head out to the garden with a flashlight to conduct a thorough inspection. Snails and slugs feed at night, so you might see no sign of them in the daytime but be frustrated to find telltale damage to your plants in the morning. You may relocate any hostages you end up with after your midnight mission to the compost heap, where they’ll find plenty to eat and actually benefit your garden instead of threatening it.
If slugs and snails are feasting on your garden’s young shoots, the damage may vary in its visual appearance. Where one of these pests has chomped on leaves, you’ll find irregularly shaped holes, while truly tiny seedlings may be eaten up whole, leaving empty garden plots without a trace of greenery.
If your garden is truly plagued with these pests, you may find it necessary to really baby your seedlings, raising them in containers indoors where they’ll be safe. Once the young plants are out of their vulnerable phase, you can transplant seedlings into the garden as they should now be strong enough to fend for themselves.

Protect your Seedlings with an Electrified Barricade as a Final Line of Defense Against Slugs and Snails

When it comes to actually stopping these notorious garden pests in their tracks so they can’t reach your seedlings to damage them in the first place, you can depend on a DIY “electric” fence that will only zap slugs and snails. Some gardeners prefer using other methods, such as a moat system filled with liquid to drown the mollusks as they strive toward the seedlings, pie pans buried at ground level and filled with beer, or the rhubarb leaf traps we describe here. Others of us depend on building a barrier wall or fence of sorts to keep slugs out and seedlings safe. Here are a few options for each method that other gardeners have successfully used to defend their precious young plants.

Use recycled food containers to create a fortress to seal slugs and snails out that will literally electrify trespassers.

Start by saving the sturdy, cylindrical containers some groceries come in, like the ones yogurt or butter are sold in. You’ll need one container per plant you want to keep safe with a barricade. Here’s a complete supply list for using food containers as barricades.

Durable cylinder-shaped containers along with their lids
Ground staples or other tools to fasten each container to the ground (2-3 per barricade)
Copper tape with a width of at least one inch
Scissors or knife

Cut the bottom of the container completely around its circumference and remove it. Then use the scissors or knife to punch holes for your fasteners, if needed. The holes should be between half an inch and one inch from the container’s bottom edge and wide enough to insert your chosen fastener.

Wrap the copper tape a little higher than halfway up the container, overlapping where the ends meet a bit and doing your best to prevent any wrinkles. Then add your fasteners, threading them through the holes you created for them.

Use the fasteners to anchor your barricade in the soil, making sure the edge of the container is at least level with the ground. You can even push the container down into the soil a bit for even more strength.

The extra jolt of power for this trap comes from the copper tape (which may have seemed to serve no purpose when you built the barricades). That viscous goo covering snails and slugs is full of ions, and when those ions come into contact with copper, the slug or snail feels an electric shock that persuades it to change course. The one-inch copper tape width is important here to make sure a strong enough reaction is produced to convince slugs and snails to turn around instead of toughing it out.

Make sure to collect all your barricades, storing them at the end of the season to be used again next year. Check them for wear and tear such as cracks or holes that would allow a slug or snail to sneak past the barricade in search of the seedlings inside. For a mini greenhouse effect that locks in valuable moisture and keeps seedlings shaded, cut a hole in each container’s lid and put the altered lids on top of the barricades. More delicate shoots will prefer containers with clear lids, while other plants flourish under opaque lids.

Videos About How to Protect Seedlings from Slugs and Snails

A how-to video from JacobsBackyardGardening gives you the rundown of organic ways to keep slugs and snails out of your garden.

Brainy Garden introduces plants that will do their own deterrent work against snails and slugs in this feature, which runs just under five minutes.

https://www.youtube.com/watch?v=dofcvm5ADus

Get a firsthand look at a tactic for fighting slugs and snails in the garden that’s a lot like the one we presented above (just without the extra voltage) in this demonstration of how to make plant protection cups or baited traps.