Introduction: Failed Project: Keeping Snails Away From a Vegetable Garden

Picture of Failed Project: Keeping Snails Away From a Vegetable Garden

When growing own vegetables one of the challenges faced is to keep predators away from the fruits and leafage. A feared creature in this context is the snail. This Instructable documents a fruitless attempt to refuse these animals access to the vegetable garden by using a dedicated but harmless fence. Step 1 documents the design criteria and Step 2 describes the test setup. Step 3 shows why the fence is not effective in stopping snails and slugs.

An alternative but likewise not very effective attempt has been documented in Step 4 of this Instructable: attracting snails to places from where they can easily be caught and then evicted from the vegetable garden. Experiments using Upside Down Dinner Plates on the soil (snails are attracted to the early morning condensate, preventing dehydration) showed a hit-rate of approximately 10%. Note that the setup described in Step 4 might not work at all under some climatic conditions.

Step 5 documents some other suggestions for dealing with the animals in a way that is ecologically sound and, most probably, much more effective than the efforts presented in Steps 1 to 4.

The purpose of documenting these attempts in an Instructable is to share the lessons learned and to possibly benefit from the experience from others that have dealt with the same problem. As the pictures have been licensed under CC BY they can be reused in other Instructables (thereby mentioning openproducts).

Another gardening-related Instructable by Openproducts is the Multi-Row Hanger for Gardening Tools.

Step 1: Design Criteria

Picture of Design Criteria

The following design criteria have been applied for the fence:

 - Animal friendly functioning: just block the way through, no pain or death involved;
 - Environment friendly: use non-toxic materials, no poisonous substances, no impact on growing process for the vegetables;
 - No maintenance required: the purpose is to realize a lower snail-density inside the vegetable garden and a higher snail-density outside the vegetable garden, without the need of evacuating the snails (this criterion is not met in the solution described in Step 4 of this instructable, the Upside Down Dinner Plates);

The targeted basic principle is to create a barrier that is simply uncomfortable for the animal: the idea is that the snail prefers to crawl along the fence instead of crossing it. The second criterion resulted in the choice of untreated wood as a construction material.

The next step describes the test setup and Step 3 documents the effect of the fence.

Step 2: Fence Test Setup

Picture of Fence Test Setup

For the purpose of testing it was considered sufficient to create a small triangular area (approximately 50 square cm) bordered with a fence of a few centimeters high. The fence has been made by lining up cocktail picks and might look quite scary from the ground because of the life-sized sharp tips. Would the test have been successful, the plan was to micro-fence the whole border of the vegetable garden. 

A snail and a slug were placed inside the walled area, surrounded by delicacies (spinach leaves) to provide an incentive for breaking out.

Step 3: Breakout

Picture of Breakout

It was impressive to see that the sharp edged fence had no perceptible effect on the snail in question, it just elegantly sneaked away over the tips. The snail was examined after the event and was found in perfect shape.

The same applies to the slug, with the only difference that it decided to benefit from a weakness in the test setup design, namely the edges. This is really smart.

As a reward of demonstrating their capabilities for breaking out the test setup the delicacies were all granted to the animals.

Thus it has sufficiently been demonstrated that a fence as used in this instructable is not effective, and the project can be considered a failure.

The next step shows an alternative approach using Upside Down Dinner Plates.

Step 4: Upside Down Dinner Plates Attracting Snails

Picture of Upside Down Dinner Plates Attracting Snails

An alternative but likewise not very effective attempt is to attract snails and slugs to places from where they can easily be caught and then evicted from the vegetable garden. Experiments using Upside Down Dinner Plates on the soil (snails and slugs are attracted to the early morning condensate) showed a hit-rate of approximately 10% (in one month a number of approximately 50 snails and slugs have been caught using fourteen plates). Note that this setup might not work at all under some climatic conditions. It is important to leave an opening for the snails and slugs to enter their hiding-place.

Main drawback to this approach is that it's a lot of work to turn over all dinner plates every morning, especially since a minimum number of plates seems to be required for assuring sufficient coverage. Moreover it's not a very pleasant job to collect the animals and evacuate them to places where they do less harm.

It would be a nice follow-up project to design an Arduino-based detection system: a flashing LED indicates when a snail is detected under the dinner plate, to ease the efforts of the detection process. Another improvement regarding aesthetics: use brown plates instead of white plates.

The next step documents some other suggestions for dealing with snails and slugs in a vegetable garden. These suggestions are not so much to fight the molluscs but rather to understand them and to make them behave in a way that is easier to control, all in an ecologically sound way.

Step 5: Natural Snail and Slug Management

Picture of Natural Snail and Slug Management

First of all it is important to stress that snails and slugs in principle are beneficial to a garden. As most of the species prefer rotting plants over fresh leaves the animals are not always a threat to a vegetable garden. Moreover, snails play a role in the lime balance of a land. Natural enemies of snails and slugs are the hedgehog and some birds. Their eggs are being eaten by many birds, insects and rodents. Birds are attracted by a garden with a lot of slugs and snails.

Some plants appear to have the effect of chasing snails and slugs. Planting these in the vegetable garden in combination with the creating of a natural habitat for snails, slugs and their predators nearby might be the road to success. This means that fallen leaves and branches should be left on the ground, or at least collected and stored inside the garden.

Based on the above, including the failed projects in the previous steps, it can be concluded that a more natural approach to snails and slugs management is likely to be more effective than fighting them. Note however that it might take quite a while before a satisfactory equilibrium has been restored.  The approach with the 'Upside Down Dinner Plates' as documented in Step 4 may speed up this process, although it might feel like carrying coals to Newcastle.

Step 6: License CC BY

Picture of License CC BY

This Instructable is made available through a Creative Commons Attribution (CC-BY) license.

Republishing this Instructable is allowed, provided it is being attributed properly (cite the name Openproducts, link to www.openproducts.org or www.instructables.com/member/openproducts or the original Instructable. For other arrangements send a Private Message through the instructables member page (www.instructables.com/member/openproducts).

Although this Instructable can be considered a failed project it may still be a good starting point for an exchange of ideas and experiences. The 'Natural Snail and Slug Management' suggestions in Step 5 offer relevant information. Feel free to post your suggestions as a comment to this instructable.

If this design infringes any rights then refer to Article 28 in the Terms of Service (www.instructables.com/tos.html).

Comments

midiansangel (author)2016-12-26

The resident hedgehogs here are "failing" at the slug control. I think the 100% organic-ness of my garden attracts more than they can cope with.

Because I can't kill slugs, it's a nightly "slug slinging" quest. Pick up slug and sling it over into the woods - not very effective long term.

I now use a length of copper wire around raised beds. Best I could come up with.

Mindmapper1 (author)2015-06-19

Electric fence works like I have shown in my recently featured instructable.

SkUG (author)2014-09-28

Best thing for slugs snails... a kebab skewer and go out at night, they are most active then, and and do your best vampire hunting impression... or get a pond with lots of frogs! :) beer traps work well too

Slugs will burrow, if you turn your soil over it will make a massive reduction in the slug eggs and of course, less slugs - snails like to hide under the rims of plant pots and other hidey holes during the day

Not sure if it works on slugs but borax (not the substitute as far as im aware) is micropointy (i'm sure there is a technical term for this) and it deters and dehydrates ants...

Recently there has been a bio slug pellet (i'm not a fan of pellets normally) released on the market that contains wool... since I have given up planting my own veg (for the moment as im selling my house) I have yet to try natural sheeps wool around my veg but maybe worth a try?

Good luck and enjoy your home grown veg :)

Victor805 (author)2014-01-21

Make holes in the ground to bury some cut beer cans or iogurt pots (anything goes in) and fill them a bit with beer, the snails will fall into them and won't go out.

unclecp (author)2013-12-15

Well..the fence is a good idea and maybe all you need is to add a few cents extra to the project. Literally. US pennies minted 1982 and earlier are 95% copper. Stick some pennies at regular spacing between the toothpicks close enough together where the slugs or snails would have to touch a penny to get over the fence and you have a copper "electric" fence for slugs and snails. The copper supposedly gives them an electric shock.

KlockworkKevin (author)2013-06-08

Very well documented Instructable. I agree with tim_n about beer traps, The best results I've had are taking a container deep enough to drown snails/slugs in, burying it in the ground so its top is flush with the ground and easy for snails to crawl/fall into, and pouring a little beer in it. Just dump out the drowned slugs/snails(and cockroaches-they love it too) in the morning for the birds to have a nice little breakfast snack and repeat in the evening. After a few cycles the ridiculously large snail population my garden had created was a lot more manageable and I started only having to do it every couple days.

tim_n (author)2013-06-05

It's a novel approach, though doomed to failure, I've observed snails crawling up needle sharp spines. Beer traps, copper tape/pipe works well. Not tried oats, been too wet in the years I've thought about trying it. Hammers deal well with snails as well, though it's not so good for the snail.

liquidhandwash (author)2013-06-03

Cool I would like to see more failed instructable I have a few myself. I have heard that snail don't like copper but Ive never tyred it.

Thanks liquidhandwash for supporting the idea. When I published this Instructable I suggested 'Failed Projects' as a new category...

I suggested a failed comp in the contest ideas forum on June 1 ( great minds think alike! ) If we have a few more member support the idea maybe it will fly
https://www.instructables.com/community/Got-contest-ideas-Want-to-help-HQ-staff/

BigBadgers2001 (author)2013-06-03

I love the fort like fence idea, and I believe we learn so much more from failed projects that it can not be a failure, just a progression. Copper is excellent against snails and slugs. I have successfully used copper tape on my pots, planters and raised beds to great effect. Another good thing to try is porridge oats or powdered bran for around individual plants. It really frustates them as the slime is absorbed quickly and they cant get purchase. Also try to atract more local birds and hedgehogs into your garden. Natural predators rock!

Thanks BigBadgers2001 for sharing your experiences. I've read about the copper tape before but I was unsure about its effect on the soil. To put them on the outside of the pots (if present) will not harm though I suppose.

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