Sluggo...IS BAD??!?

After several years of struggling with slugs and adding controls and deterrents hither and yon, I decided to go the way that so many have and try Sluggo. After all, it's just iron phosphate!

The iron phosphate in Sluggo has to be chelated with EDTA to be effective and invite slug ingestion. Because manufacturers add EDTA to human food and the Gov says it's ok, it's fine! I just read a thread on here in which a Sluggo saleswoman ate some to prove how safe it is. Webmd sez: "EDTA bound to iron is used to “fortify” grain-based products such as breakfast cereals and cereal bars. EDTA is also used to help preserve food; and to promote the color, texture, and flavor of food."

Sounds great, maybe I can believe that it's nontoxic (per U.S. FOOD AND DRUG ADMIN. or U.S. DEPT OF AGRICULTURE) to pets etc. because EDTA and iron are surely in their food too.

Then I found a blog post by a Northwestern gardener (we know from slugs!) who cited this paper on Sluggo toxicity in earthworms, among other things.

I scanned the studies the paper quotes and here's my TLDR on earthworms:

Edwards et al (2009): You probably couldn't use enough Sluggo to achieve the earthworm toxicity they demonstrated. (study funded by Sluggo distributors)
Langan and Shaw (2006): If you build a house out of worm food mixed with Sluggo, it's bad for worms, but who does that? (research engineering assisted, and some materials provided by, Sluggo distributors)
Luhrs (2009): a better study than the other two because it was a realistic field study conducted over time. At "relevant soil concentrations", Sluggo is not a hazard to earthworms. (sponsored by Sluggo manufacturer Neudorff)

...and on microorganisms:

Results of a different trial showed that EDTA caused stress to soil microorganisms, as indicated by a significant increase in the trans to cis phospholipid fatty acid ratio (Grčman et al., 2003)
In contrast to Grčman et al. (2003), Chander and Joergensen (2011) did not observe an effect on fungal biomass when EDTA (500-2000 mg/kg soil) was added to heavy metal polluted soil.
Epelde et al. (2008): EDTA had significantly negative effect on the soil microbial community activity; potentially mineralizable nitrogen, potentially active microbial biomass, and three soil enzymes not affected.

These studies on microorganisms used amounts 10,000x what the expected field soil concentration would be. (I don't see how that's even helpful, anything is poisonous in appropriate concentrations.)

CONCLUSION: For my part, Sluggo is still in the armamentarium, but I'd be interested to hear any thoughts, particularly if folks want to read the Technical Evaluation Report themselves. The blogger who originally referenced this TER decided not to use Sluggo.

Thanks for this legwork - so many things that we think or assume are inert/safe/natural turn out to have some potentially bad sides.

Of course, water can be deadly.  So can oxygen.  Its all about concentrations and such.

That paper - well, regulator response? - is interesting.  A few things I took away ...

1) EDTA can be bad for soil microbes.  Although "can" means that they took the recommended dose rate and went big with a dose 11,000 times stronger!  Yep, that had an effect!  So even applying at an abnormally heavy rate, you're not going to get to 100x much less 11,000x
2) EDTA has an interesting benefit ... it tends to make heavy metals more soluble (effectively ... it enhances chelation).  Thus when trying to use plants to accumulate heavy metals, EDTA application can make that process faster/more efficient.
3) at least one version of EDTA seems to persist in the environment, and its especially good at stripping calcium from our bodies.  I can't determine if its allowed for organic crops, but it seems to be aimed at gardeners instead?  And its OMRI listed...

I'm curious how others react to these findings.

A comparison - we use copper mesh around the planters.  That works amazingly well - although I suppose we are adding some copper to the soil...

That's fascinating about EDTA and heavy metals. I've looked into plants for lead remediation and it's exciting that EDTA can help. If you know more resources for that I'd appreciate your sharing!

I too use copper around planters and as a border around plants. I should make sure to soil test for copper this year as it might be accumulating. Do you keep your copper brightened? Because electrical conductivity is adversely impacted by tarnish/patina, I'm thinking about throwing all my copper strips in a bath of lemon juice or vinegar-water and salt before placing them this year. They've been around a while and may need some polish to zap those slugs.

Sounds like something that costs money.  

There are way better ways to deal with slugs without spending money.  And even more ways that bring money (duck eggs sell for $12-30 per dozen here!)

I suppose it would be good to keep as a possible weapon in the arsenal, but doesn't seem like something I would want to use very often.  

Bait them with piles of oat bran, it'll swell as they digest it and they'll either die or be immobilised ready for wildife or poultry to eat them. Makes sure no pets are around, molluscs carry lungworm.

It's invaluable here for early control of baby slugs, if you let the slugs grow (invasive spanish slug crosses) they get to big for pellets, they would need to eat more than practically possible to kill themselves. If you hammer the slugs as babies you keep them down for the entire year, most of you have seen the buckets of the things I can collect in just a few minutes, that's after hitting the babies in spring if you don't do anything you simply can't grow anything at all. None of the native wildlife eats these slugs and ducks are not allowed in vegetable gardens (or orchards up to certain dates before harvest) if you want to sell anything (that is also true in the US)
Once the slugs are adult the only way to control them is hand picking, seriously impractical on larger scales. I'm not at all worried about something that is toxic is such hugely overdone doses, I suspect if you add any chemical to the soil in such a high doseageit is going to change the soil biome no matter how benign or otherwise it may be.

Fredy Perlman wrote:
I too use copper around planters and as a border around plants. I should make sure to soil test for copper this year as it might be accumulating. Do you keep your copper brightened? Because electrical conductivity is adversely impacted by tarnish/patina, I'm thinking about throwing all my copper strips in a bath of lemon juice or vinegar-water and salt before placing them this year. They've been around a while and may need some polish to zap those slugs.

That's a good idea ... alas ours is affixed to the planters so its staying there for the time being!

R Ranson, unfortunately looking after more animals is too hard for me. I had ducks before and would love to again! Indian runners, though next time I might get a drake. The poor girls were all confused without that big pest.

I am currently thinking to up the biological controls again this year, rather than turn to science & manufacturing. The oat bran sounds really exciting, but I wonder if it would work in a 90-100% humidity environment. Hygroscopic materials fare poorly here.

But I will try anything, especially considering Skandi's note that hitting them early is key. I've never done that.

What makes me laugh is where science and permaculture miss each other in the night: Sluggo kills slugs eventually, and snakes eat slugs, so what happens if a snake eats a Sluggoed slug?

Beer traps worked so well for me when I was gardening in the city.  It was an allotment so I had no control of the environment outside the garden bed. But beer traps with the cheapest beer possible would remove enough slugs each night to prevent any slug damage.  

The garden one over from mine used egg shells and swore that it worked.  I suspect it was that my beer traps were drawing all the slugs away from her garden... but maybe it was the shells.

Fredy Perlman wrote:
What makes me laugh is where science and permaculture miss each other in the night: Sluggo kills slugs eventually, and snakes eat slugs, so what happens if a snake eats a Sluggoed slug?

Theoretically nothing, the iron is only meant to kill molluscs, which is why it is sold as pet etc safe, and that saleswoman could eat it. The toxicity of the old pellets is why they are now banned in many places, there there really was a danger of by kill.

r ranson wrote:Beer traps worked so well for me when I was gardening in the city.  .... But beer traps with the cheapest beer possible would remove enough slugs each night to prevent any slug damage.  

There's some interesting possibilities here ... have a drink and squish party!  Squish a slug, take a drink!  Eventually there will be beer containers with a fairly random scatter on the ground to catch those that avoided the squish!  And maybe some warm bodies too, to help warm the spring soil!  Probably adding nitrogen to the general area too...

r ranson wrote:Beer traps worked so well for me when I was gardening in the city.  It was an allotment so I had no control of the environment outside the garden bed. But beer traps with the cheapest beer possible would remove enough slugs each night to prevent any slug damage.

R Ranson this is a tactic I've always wanted to try, but I feel I'm still lacking on the details. Could you describe exactly how your beer trap tactic worked? Like, what did you use for the container? How big/deep was it? Did you bury it? Was the surface of the beer at ground level, or did they have to climb over a brim and jump in to reach it? Did you need to leave the beer open to get warm and flat first? Where did you set the traps - in the middle of your beds, in the pathways, etc, and (last one) how many traps would you set over how many square feet?

I would love to up my slug game this spring, but I've never been interested in purchasing yet another pest control product like Sluggo. It's more the economics of buying in single-use consumables that turns me off. So far I've been relying making my garden less hospitable for them, like cutting the grass as short as possible to dry everything out and eliminating any sort of slug shelter like exposed cardboard or small rock piles. I've also had noticeable success with attracting snakes and skinks with strategically placed basking stones.... But I do still have to pick them off everything after a rain...

WARNING to sensitive readers, the following post is not for the faint of heart...

I had a lot of slugs & snails in my garden when I started, a lot. I also have an old half-full container of Sluggo in the arsenal. What has stopped me from using Sluggo is mainly the fact that it comes in a trashy, single-use plastic container. I mainly fear "recycling" said plastic Sluggo container or throwing it "away". Instead, over the past several years, I have developed a new strategy that involves 2 simple garden tools: a trowel and a dedicated pair of pruning snips.

I try to wake up to water my garden as early in the morning as possible - when the slugs & snails are massacring my greens or are cruising towards my greens. Whenever I see them, I pick them up between the blades of my dedicated pair of pruning snips, move them a few feet away from my plants and chop their bodies in two. I then dig them a grave with my trowel & bury them, composting their carcasses in situ. When they're cruising around along the grass in the yard I pick them up between the blades of my dedicated pair of pruning snips, move them to a brown spot in my grass that needs some "amending", sacrifice them there & throw a couple of handfuls of compost over top of their bodies. Finally, I wipe remnants off the dedicated pair of pruning snips before storage. Every so often a night-time "mission" is also needed.

My slug population is now heavily reduced, my soil is healthier & my plants are enjoyed by me, my family (most of our food comes from our home garden), my neighbors & my friends and I haven't bought Sluggo in years.

Mike, although I do not like killing things this is my only way to go as well, and if done rigorously it helps.

I would love to encourage the predators of slugs but unless they are really really small (young) there are none. Birds will eat small ones and find the eggs (sometimes), some beetles also feed on baby slugs. Toads are difficult as I am suburban without much habitat around, but I am still hoping!

In very rare cases I use sluggo (which is called differently here) but it kills all beneficial and endangered snails as well.

To the one using beer: Congratulations if it works for you but here it is discouraged as it draws slugs from the complete neighbourhood to your place - so you probably have a much lower slug pressure.

I will fight again this spring to keep at least some sunflowers alive. Last year I planted more than 40 seedlings, some of them really big and sturdy, but they get eaten in one night. It is such a joy to observe the bees and then birds on the sunflowers that I will try again and again.

For other plants I simply gave in (dahlias, foxgloves, larkspur and others, they even eat my burdock!)

Last spring I was pulling a 5gal bucket of slugs and snails off of the crescent city food forest, and overwhelmed all my friends’ fowl at that rate. I have used sluggo, but the mollusks were worst when it was not appropriate to spread the stuff (warning on the label to not use before rain).

So I just started crushing the snails under foot and spearing the slugs in the head with a sharp stick or hori hori/knife. Much quicker, and I figure it keeps their biomass in the soil.

To invert our thinking a bit,  I would bet slug manure is pretty darn good for the soil, if only our plants can survive to use it!

Mike, I did exactly that with the dedicated snips all last year. Except I used surgical scissors because they're easier to carry...I made a sheath for them out of gription (inner tube rubber), a belt hanger and a paracord toggle, so I could carry them at all times, every day. It was the only tool besides my key loop that I carried at all waking hours. I killed and killed and killed, and killed! Killing was done by me. I did kills.

I made a killmountain. A Killimanjaro, if you will. And it did nothing!!! Except probably enrich the soil.

I lost burdock, lettuce, squash, cucumbers, strawberries, beets, ulluco, the list goes on. I've NEVER been able to grow carrots. i made Sluggoo biodynamic tea, which worked but requires militant discipline in application. I wrote a thread about it on permies because it smelled so much like manure tea, and believe that it had a fertilizing effect on some snap peas I tested last year. This year I will be trapping the slugs rather than hunting them.

Every year I turn up my slug control efforts; I'd say they take up 20% of my time right now. I'm only considering Sluggo because it's effective PASSIVE control...I want my time in the garden back! I have no compunctions about killing; i think of it as "correcting", because I am trying to right an imbalance created by humans. And anyway, nothing really "goes to waste".

i also have Helix aspersa and pomatia in my gardens, and I certainly don't want to kill them except with some butter and garlic.

I bought some Slug-X beer traps, made in the UK, and will be using those. They claim to catch up to 50 slugs before maxing out, and they are obviously rainproof, unlike some other beer traps. (I'd been looking for the Oregon Slug Trap, but this one looks bigger.)