Building Slug-Proof Planting Barrels




About: I'm a gardener and crafter... Always looking for a good way to do something, be sustainable and grow something yummy or make something useful.

Living under redwood trees is fantastic, with a few minor exceptions, for die-hard gardeners. My greatest curse-provoker is slug eaten plants. My seedlings hardly have a chance to get started before our slimy natives mow them down. So this project is great to protect food and flower crops from chomping AND to use containers for any reason.

So far, I haven't caught a single slug (banana or otherwise) in this set of barrels. With a drip system installed, plants remain healthy even through hot spells. This is the ultimate low maintenance system for a veggie garden! I recommend installing a drip irrigation system as soon as possible after planting or at the same time.

I could have set up all my barrels in one day, but I paced myself physically and financially by doing this project in stages. And, of course, sometimes you just run out of materials or daylight. You can split the project up many ways. Do what works for you!

Step 1: Materials

Containers - Mine are giant nursery pots purchased at a local garden center. Here's a tip though, if you get them used, you might be able to score them for free or super-duper cheap. Check Freecycle or Craig's List.

Carpet tape - You need indoor/outdoor rated stuff. It is double-sided and has a strip of paper on one side that peels off after getting it positioned. It also comes in white or black, but the color doesn't matter.

Copper tape - This can be quite pricey! In fact, you'll see it a version available that is sticky backed, but it costs more. Use it if you want to cut out a step though. My roll is very, very thin copper with no sticky backing and cost $5 at a garage sale. A steal!

Knife/scissors/pruners - I found a knife to be much more efficient. This is for cutting the carpet tape, copper tape and opening bags of soil. The carpet tape is killer on pruners and leaves them sticky, icky.

Gloves - Always! Protect your fingers from sharp edges, critters, and future sore hands.

Soil - Mix your own or purchase. You're going to need a bunch of it.

Rocks/brick/pavers - My barrels sit on river rock to encourage good drainage and level the area under my containers.

Amendments/fertilizer/compost/worm castings - I use mostly worm castings and home grown compost to make my plants happy, but you may have a favorite plant food. You can also use plant food that is specific to what you are planting (veggies, acid-loving plants, bulb food, etc).

Mulch - You'll see that I top all my beds with rice hulls. It's easy, very cheap, super sustainable, long lasting and appears to keep the cats out of my beds (doesn't feel good in their paws).

And, of course, plants and seeds - My beds are primarily for edibles since I don't have enough sun anywhere else, but I've mixed in all kinds of pollinator friendly plants and some with great foliage that will last beyond my food growing season. I also started all of my veggies from seed this year: some in starter pots on the deck and some right in the barrels. Both are doing well.

Step 2: Getting Started.

Gather your materials at the spot you are going to have the containers live. You don't want to create and fill the containers and then move them. At least, my back won't let me do that! I look for easy ways to avoid Aleve at the end of the day.

Put on your gloves and clean the containers if needed. You want a dirt free and dry surface for the carpet tape to adhere well. I use a dry rag and wipe off only the area I will be taping.

Step 3: Pull Out the Carpet Tape.

Pull out the carpet tape. I chose to do my copper section five or six inches from the rim of the container. The copper section is well above any plants and other materials near the containers for slugs to climb up and over the copper strips. If they can find a way in, they will. Your containers will probably sit in and around different materials than mine, so consider where on the container is best to place your copper. Also, I'm fighting banana slugs, so I have made my copper section much larger than you may need. It's 4 to 6 inches wide. The carpet tape location determines the copper tape location. Since the containers are tapered, you'll notice that it will have some wrinkles and folds as you adhere the tape. You want to keep the tape going around the container in a relatively straight line so you don't waste any copper tape.

Depending on how wide your copper strip needs to be, make 2 to 4 passes with the carpet tape. It does not need to touch at each edge of the tape or at each end of the strip. See the photo. The copper tape can bridge 1/4 to 1/2 inch gaps (depending on the width of the copper tape).

Now you have carpet tape wrapped around the container and the paper on the back of the tape is still in place. Using a gloved hand, rub the carpet tape with firm pressure. You are ensuring good contact between the carpet tape and the container - this is important!

And now you can peel off the carpet tape's paper backing! It may tear at the wrinkles and folds but comes off pretty well. I do this part without gloves so I can use a finder nail to peel at the tape edge. This is a great part of the project for kids to help. Just remind them to avoid touching the now exposed sticky surface of the tape.

Step 4: Copper Tape Time.

Pull out the copper tape. You are going to cover the carpet tape with strips of the copper tape in the same manner. The only difference is that you are going to start at the top edge, just a hair above the carpet tape (so no carpet tape is exposed to the elements. It becomes brittle and may ruin the whole project if it peels later), and overlap all your edges. There will be overlap horizontally for each strip and vertically and the end of each strip. Again, take a look at the photo for guidance.

Do as many rows as necessary to cover all the carpet tape. If you have gaps, cut a piece of carpet tape to fit and cover with copper.

Just like you did earlier, before removing the carpet tape backing, use gloved hands and apply firm pressure while smoothing the copper into place. This ensures good contact between the carpet tape and the copper. It also keeps critters, soil and water from getting into wrinkles and crevices.

Pat your self on the back! Take a break and make sure you are staying hydrated and not getting a sunburn!!!

Step 5: Add Soil.

If you didn't before, settle your container on top of some river rocks, brick, pavers or whatever to promote good drainage and level the container.

Scoop in soil to about 8 inches deep. You can pour soil out of a bag if you are sturdy enough to hold it over the edge - I tipped my containers over when I tried to lean the bag of soil over.

Step 6: Add Amendments.

Add your amendments. This is where I add compost or veggie/bulb/plant food in a thin layer and mix in with gloved hands.

Add more soil and compost until you have about 6 inches to the rim of the container. Here I mix in (by hand or small hand tool) a few cups of worm castings. Because I have my own worm bins this is pretty easy and inexpensive to do. If you are buying the worm castings, you can cut the amount back - or start a worm bin!

Step 7: Add Plants and Seeds!

So, now you have all the good earthy stuff in the container and about 4 or 5 inches of space to the rim. Add your glorious plants and seeds!

Step 8: Mulch!

Mulch! This keeps water and warmth in and the chance of airborne weeds down. I prefer to use rice hulls, so I scatter the hulls about until I have a nice even layer. And I have found that very insistent neighborhood kitties don't like the feeling of the poke-y rice hulls in their paws. It does no damage, but it's is merely annoying enough for them to go home and use a litter box. Feel free to use whatever mulch you prefer - if you have put in seeds, make sure the mulch isn't too dense for seedlings to poke through!

You are done!!! Water everything well and consider installing a drip system.



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    15 Discussions


    6 years ago on Introduction

    Anyone tried the copper wiring from old electrical cables? Maybe a good alternative to the pricey copper tape if you can find the wires in trash containers on building sites. Just a couple of windings around the containers should do the trick I think. I'll try to experiment with this.

    Thanks for the instructable, meganscottage!


    7 years ago on Introduction

    Wonderful. I'm trying the cheap route with some 3" wide aluminum tape. Day 3 still no slugs or snails in the containers, but we'll see.

    2 replies

    Reply 7 years ago on Introduction

    I'm proud (and lucky) to say this worked not a slug or snail in any container all summer long.


    8 years ago on Introduction

    Just an FYI, to my knowledge, banana slugs do not eat living plants, they only eat decomposing plants and material...its the brown slugs you have to watch out you may have your sites set on the wrong critters. Banana slugs are actually quite friendly as they are important decomposers. I just went on slug patrol in my garden for the infuriating brown slugs though - I'll have to try the copper technique. Thanks!


    9 years ago on Introduction

    what really works great is placing a bowl half filled with beer next the pots

    It's a bit of electrical ZAP! The slug slime and the copper create a small shock, so the slugs don't cross the copper. For the record - it doesn't kill the slugs, it is merely uncomfortable. I'm sure someone out there has a fancier explanation, but I have never had slugs cross copper in 20 years of gardening in Northern California. :) Thanks for the question/comment! It's my first post to Instructables... - Megan's Cottage


    Reply 9 years ago on Introduction

    Hmm that reaction works so well because of the metal in your fillings and the foil are different metals that react with your saliva to make a battery type reaction. That makes me wonder if using copper and aluminum would get a bigger zap and help stop larson's super slugs. just thinking


    9 years ago on Introduction

    I tried this before when I had a garden and the slugs were more determined I guess. They just went right over it. Oh well.


    9 years ago on Introduction

    if it matters to you at all, the native banana slug only eats fallen leaf litter and not the live plants in your garden, it's probably the european garden slugs that are the invasive orangey-blackish slugs that devour all your hard work! i live in washington state and i see both daily


    9 years ago on Introduction

    Good solution to the problem. For another possibility, as they say in permaculture, "you don't have a slug excess, you have a duck deficiency." A couple of ducks or geese will eat slugs all day long, give you about 250 eggs a year each for females, deposit high-quality organic fertilizer on your soil, quack to warn you of visitors, and provide meat. Also, they're even easier than chickens to take care of and are cute and fun to watch and play with.

    1 reply

    Reply 9 years ago on Introduction

    Oh, how I agree! During the winter, the seasonal creek behind the house is running and we have ducks that hang out, ride the rapids and eat my slugs... And I love them! But, sadly, our house has the fringe of a postage stamp for a yard. So, I continue to hunt for small space garden ideas and friendly community gardens for my gardening fix. Thanks for the Permaculture perspective! - Megan's Cottage