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.