This is a beer-baited slug trap made from two empty drinking water bottles. It introduces no harmful chemicals into the garden and does not harm the local wildlife (apart from the slugs). It also re-purposes items which would normally have been thrown away. Using green bottles makes it merge well into the foliage. Altogether, a green idea.

The first one was made in the space of 5 minutes last week. I have had slugs eating my plants, and a work colleague mentioned the same thing just as I was pouring fizzy water from a bottle. It was one of those 'eureka' moments. I had several of the bottles in my cupboard which would 'come in handy one day', and that was the day! 5 minutes later using only office equipment, I had the first slug trap built.

Step 1: Tools and Materials

As I said earlier, this was knocked up in 5 minutes in the office.

You will need two water bottles for each trap. Use the ones with the base moulded into 4 sections (see picture). You could use the 5 but they would be trickier to cut and merge.

The tools you need are stapler, marker pen, measure, scissors.

Also, you'll be needing BEER for bait . . . see later.

Step 2: Measuring and Cutting

Mark a line three inches (75 mm) from the base of the bottle. If you leave the label on you can use it as a cutting guide. If your bottles are identical you don't even need to mark - just follow the label around. Draw down to the ridge around the indentations about 1" (25mm) up from the base. Do this in the 4 places.

Cut around the bottle, and then down to the bottom ridge. Then cut across in two places to give the shape shown in the third picture.

Step 3: Putting It Together

Now you have two identical halves, slot them together to give a 'window' in either side.
Use the stapler to clip them together. Two staples through each side makes it good and solid.
Make them as low as possible, but the limiting factor is the width of the stapler.

Once you've made one, make some more!

Step 4: Setting the Trap

The bait for the trap is BEER. Slugs can't resist it and will slime their way into it, drink, and eventually asphyxiate (but what a way to go!).

Put the traps down, push them into the soil a bit and bait them with beer. Don't worry about slugs not getting up the side - they are born with commando training and will find their way anywhere. Weight the traps down with a stone.

Notes on beer.
Beer is anything from the lightest golden brown, through amber (possibly with a reddish tinge) to dark, dark, dark brown, and when a sip is taken it should overwhelm the senses with the aroma of hops and malt. It should conjure up visions of drying sheds, malt shovelling and barley fields rippling in the summer breeze.
Beer is not a thin insipid beverage which looks roughly the same leaving the body as it did when it entered it. Some breweries have a problem realising this.

It seems the darker the brew, the more the slugs appreciate it. It's probably the malt which attracts them. I unearthed a bottle of 'BLACK NASTY' in the loft - a homebrew which knows nothing of 'best before' dates - this was past it's prime from day one! but the slugs seem to relish it.
However, they don't object to the cheapest supermarket product either, so if you're not normally a beer-drinker, just buy one bottle or can.

Once the traps have been down a while, recycle the contents onto the compost heap and refill the traps. Let the little blighters do us some good for once.

WARNING - Under no circumstances smell this after it's been down a couple of days. I accidentally got a whiff and spent the next couple of minutes trying desperately to keep my lunch down. I was so overcome that I forgot to take photos of the body-count :- From three traps after two days - 2 large, 5 middling and 4 small slugs.

Not total wipeout yet, but I feel now that I'm doing something to redress the balance and stop the devastation of my plants.