In the short time I have been growing my own fruit and veg slugs and snails have become my enemy number one, causing destruction that has cost me several kilos of fruit and veg. I have been fighting a running battle with them and so far this year my losses are much smaller. Here are my top tips for beating slugs:
1) Plant seedlings rather than seeds straight into the ground: A lot more time consuming but I was losing 90 percent of the new seedlings, which were having their heads bitten off as soon as a millimetre or two of green poked out of the ground.
2) Barriers: cutting the top and bottom off plastic bottles, including plastic milk bottle, and placing them around the seedlings seems to have really made a difference. Also helps reduce weeds as you can water direct into the container and the plant, and not watering weeds as well.
3) Eggshells: crushed eggshells do work, they stick to the slimy skin of slugs and snails and they hate it. But once it rains, which is when slugs and snails are most active, they stop working. Over winter I keep saving my eggshells in a bucket in the shed and use them in the spring and summer.
4) Sluggo: organic slug pellets which don't harm wildlife and fertilise the earth when they break down. They take many days to break down even in light rain so keep working when it does rain. The metal compound in them acts like an internal grenade, very satisfying. They work really well.
5) Scissors. I suggest a nice big pair of kitchen scissors used solely for cutting slugs in half. On a good (or rather a bad day) I have chopped more than a hundred in half. Don't feel bad, a single slug can produce 90,000 grandchildren. Going out in the rain with a torch in the dark can be very productive. I recommend doing two rounds. One earlier on, and then one an hour or two later. Slugs are cannibals, and the recently chopped up slugs will act as bait. I often go back and find slugs feasting on their fallen comrades. Snip snip!
6) Grapefruit: The skins of grapefruit cut in half and placed flesh side down seem to attract slugs, making it easier to find them and chop them in half with scissors. Some say they also distract slugs from plants.
7) Beer traps: I tried this once but I seemed to get more slugs and snails. I think word got around and slugs from all over the neighbourhood turned up for free beer.
8) Nematodes: Two people I know who have used them say they really do work but they are expensive and apparently not very effective on heavy clay soil, which is what I have, so I have not tried them.
9) Removing hiding places: Keep the area around where you are growing things clear of long grass or dense plants, or any other hiding places for slugs and snails.
10) Netting: I have noticed that where I have netted fruit and veg to protect it from birds and foxes, it also acts as a barrier to full grown slugs and snails, which can't get through it. (Obviously depends on the size of the net holes.)
11) Water in the morning, not the evening: I know advice is that evening watering is better to allow water to soak in when its cooler and not leave water on leaves in hot weather, but you are making the surface exactly how slugs and snails like it to reach your plants, at exactly the time they like to go out for dinner. A soak in the morning instead will allow the surface to dry off during the day, making slug and snail transport less easy.
12) Rake the earth around plants which have been attacked. Slugs and snails can follow their own trails back to where they had dinner the night before. disturbing the earth breaks the trail, making them have to search all over again.