Tuesday, September 7, 2010

War on Slugs

A cabbage seedling, nearly devoured by slugs.

Living in the Pacific Northwest has gardening pros and cons. With the amount of rain we receive and mild winters, slugs are unfortunately one of the most problematic of cons. Especially since I have moved to the country, where there is so much forest litter and shade. Go out at night with a flashlight and you will quickly see the 4 or 5 inch long slugs everywhere. And they say that slugs can consume their own body weight every day.

I cannot tell you how many seedlings I've lost this year due to these nasty beasts. So many lettuces, all of my eggplants (which I sowed three times!), most of my numerous bean plantings, all of my pickling cucumbers... the list could go on and on. But when I lost all of  my gorgeous fall broccoli plants overnight... well...... that's it, slugs! This is WAR!

Slugs are an ongoing problem for every vegetable plant, every year. If I really want to grow a large percentage of my own food, I've got to get really serious about keeping them under control.

This is just the beginning of my venture and I will be regularly updating the site with any new information I find.

So I'm on a mission to try and get rid of these suckers as much as I can. And to find out what garden remedies work, what's a waste of time, money, effort.

Please note, before you begin your own mission, that not all slugs are detrimental to your garden. The Pacific Banana Slug, which I learned from Throwback at Trapper Creek is beneficial. Actually it sounds like this particular species performs work very similar to earthworms. Oops.

Reduce slug habitat:
My first mission, which will be laborious, is to reduce slug habitat as much as possible. Slugs seek out moist, dark places to lay their eggs and to hide during the day. Forest and leaf litter are prime examples (which also comprise part of their diet). They will also hide under anything: rocks, wood, ground covers, pots...

Sadly, this means I'm going to have to move a lot of rocks. I don't know why it is sad... I guess I just like the look of rocks in my garden. I have used, and am currently using, rocks as traps so that I can destroy them. But so many rocks is really very time consuming and probably does more harm than good since I can't find time to look under all of them. Using long, flat boards works better for me.

I've noticed that adult slugs like to lay their eggs in ground covers, as that is where I find the most baby slugs. So part of my regimen will be reducing grass around the gardens, which is where the new tiller is going to come in handy.

I will be working on keeping the leaves tidy this fall with my new leaf blower.

Search and destroy: I can attest that this is the least inexpensive and most effective way to reduce their populations. Unfortunately it is arduous and disgustingly gruesome task, which is exactly why I am not consistent with it. Yet I've noticed that when I am consistent the slug population reduces dramatically.

Since slugs come out at night, the simplest way to track down your prey is to go out at night with a flashlight and destroy the slugs you find. Or collect them as food for your chickens or other livestock. Bleck. I know, this is just the way you want to spend your evening. Just do it with a glass of wine if that makes you feel better.

On destroying them: some people use a salt shaker so as to not have to touch them. I've used this method before, and it works, but only if you use enough salt. How much is enough? Not sure. But I have seen them slither away after only using a few specks. And some people say that you shouldn't use salt because it raises the salinity of your soil.

The simplest method for me is to use scissors. Ew! Yuck! I hate doing it. But it is easiest. Just snip them several times (most humane, I think. no need for them to suffer if indeed they do suffer) and look away.

You could try squishing them, but once they are large it is hard to do. And gross. Just think of what happens when you step on a ketchup packet.

The best time to search and destroy is after irrigating or after a rain following a dry spell.

Traps:
I find that using long, flat wooden boards placed wherever you need them to trap your prey works very well. If it is dry underneath the boards they won't come so you have to be patient.

Another trap/lure that is popular is beer placed in shallow cans. But I stopped doing this a couple of years ago. This is because I went out one night and placed every slug I found in the beer trap, thinking this would save me the agony of having to dispatch them. But, much to my horror and surprise, not all of them drowned. That's right! Many of them just slithered right out. So that got me thinking that it's possible beer may in fact just be feeding the slugs.

I'm revisiting the idea of beer traps. Perhaps the error in thinking is that the pan has to be shallow. Maybe they will all be attracted and drown if the vessel is deep enough. But I went to the grocery store the other day, with the intention of buying a large amount of cheap beer to make the lures. The cheapest beer was 71.5 cents/pint (which is two cups). I'm thinking my traps will at least need to be 8" deep, and with the amount of traps I need.... Well, let's just say I hate buying things. Sorta defeats the purpose.

I've read that some use their own yeast/sugar or honey mix for their traps. I'm going to do an experiment soon and will update you with the result.

Predators:
Environmental predators include snakes, frogs/toads, salamanders, all of which live abundantly in my yard. If they didn't live here already I would be attempting to provide habitat for them. At the very least, I am hesitant to do anything that may harm them, such as using chemical baits for the slugs, which the beneficial predators may consume and die.

Introduced predators would include poultry (esp. ducks). Chickens will eat slugs if they are small enough. I've read that pigs will eat slugs, but don't know that reliably.I've also read about using beneficial nematodes in the soil, and I hope to devise an experiment soon if it seems financially feasable.

Baits:
Iron phosphates: such as Sluggo or Escargo are the baits that are preferred for "organic" gardening. I've used them in the past, and they appear to work (again, another experiment in order!) but they sure are expensive. A visit to the nearest hardware store revealed nearly $20 for  a 2.5# jug. Ouch. As I said, I hate having to buy things, especially something that comes in plastic.

Metaldehyde: is the "conventional" standard. But we've all heard how terrible they are. The previous owner left a box of Cory's snail and slug bait (a sign of things to come?) and I am terrified of it. I can't just throw it out as it doesn't seem right.

Other repellent methods:
wood ash (doesn't work), coffee grounds (myth), coffee, diatomaceous earth (didn't work for me), cornmeal, copper (no use), slug repellent plants. These are all "remedies" that I would like to do experiments on.

Anyone out there have any other tips on dealing with slugs?



For a list of all of my slug control experiments, please see this page. 

9 comments:

Grace Peterson said...

Hi Amy Dear, I use the low toxicity bait. It doesn't seem to hurt anything or anyone but again I don't have small kids or animals other than cats who know better.

In the last few years I'm noticing more snails than slugs. They don't do as much damage but they're still herbivores. ... It's an ongoing battle and with this recent rain, yikes, they'll be out in droves. Which I had some advice...

hybridhopes said...

*some* chickens are decent slug hunters. My plymouth barred rock LOVES slugs and will eat anything about 1.5 inches and smaller. My larger australorp apparently finds them disgusting, or intimidating.
I've heard ducks are good at slug control.

afreckledlip said...

I have been using the beer traps and have had fairly good luck, although you do have to change them often. I have been using old margarine, cottage cheese or similar sized containers (their only about 4 inches across and maybe 4 inches deep). I put them out the other day when it started getting rainy and the next day had over 20 slugs in my traps. I'm also still looking for that one thing that will keep them off my garden. Have you tried copper, I've heard it works well. Have you tried it?

Amy Manning said...

Actually yes I have tried copper. Doesn't work. And I've found with the beer traps that it will capture some slugs but the others will take a big drink and move on. You can see all my experiments here: http://amysoddities.blogspot.com/2010/09/slugs.html

Barbara said...

Hi Amy, thanks for your comment on my own slug blog post. I see that you've had many of the same experiences I have and seem to have a similarly terrible slug problem. One of my neighbors has less trouble than I do - and I know that he spends lots of time keeping the earth around his plants completely smoothly packed, and never uses mulch, removes all leaves, etc. So reducing their habitat seems to help. Otherwise search and destroy has worked best for me, in addition to just not planting lots of things. Maybe not a solution for you if you're trying to be self-sufficient.

Lucy said...

Hi Amy,
love your blog! I also have a war on slugs. Being vegetarian I couldn't kill them for a long time until the day they ate all my potato plants. Then it was On!

I also find the plank'n'kill method is the best. I have a mini-bucket (pail?) - I add a big squirt of dishwashing detergent and half-fill with warm water. The slugs sink like a rock to the bottom, no gross squishing or slicing! I'm not sure why, but my guess is that disrupts their breathing mechanism and suffocates them fairly quickly. Certainly when I was dropping them into my yeast/honey/whiskey/water trap, they'd crawl right out... 2 or 3 times each slug! It was traumatic.

The soapy water still works when the water is cold, so I leave it next to my vegie patch for 24-hour slug-killing capacity. I empty and refill the bucket twice a week (when they start floating to the surface.. ew!).

Good luck :)

Amy said...

Hey Lucy, thanks for stopping by. I did do a little experiment with traps. You may be interested reading that article. I am still transferring pages from my old site and see that it isn't up on the new site yet. Hope to have all the rest of the pages updated today. What part of the country are you in?

chris said...

When I pick them off by hand, I use a little plastic spoon and a cup of saltwater. I just scoop them off the leaves or the ground and drop them in the saltwater. None of them ever survive to crawl back out. And then I just pour the saltwater into my trashcan before going back into the house. The whole affair rarely takes more than 2 minutes per raised bed.

Lynae said...

Hi Amy,

I found your War On Slugs entries while searching for different ideas for slug and snail repellent / killer. I've been looking for a quick fix because I'm going out of town for a week and can't do any "picking" when I'm not here...so I'm worried all my little plants will be going by then :(

I just wanted to weigh in on the cornmeal idea. It's a total myth. One of the things we've been doing with our excess snail population is cleaning out their digestive systems in a fishtank for a few weeks and then eating them--and one of the main things we feed them is cornmeal. I realize snails and slugs aren't the same, but I doubt there'd be something that one loved and the other hated!

Also: I just wanted to echo that coffee grounds don't seem to work. I've been using used coffee grounds as a soil amendment and the snails and slugs have no problem crossing it, at least in the small amounts I've added to the garden so far. However, research does seem to show that caffeine kills young snails and slugs and repels the older ones...maybe there is just not enough "available" caffeine in used grounds or dry unused grounds? The research was done with a caffeine spray, but the amount of caffeine involved was about the same as drip coffee. Maybe it would be worth trying pouring some day-old coffee around the plants?