Warm winters can disturb the hibernation of slugs and snails.
They will eat and breed throughout the winter months, creating an extra generation of molluscs that will continue your infestation.
Slugs are very benificial in the compost heap but unfortunately they may not stay there and the heat generated by the pile of decaying matter may just be enough to take their breeding cycle to a new high.
Adult slugs can eat 40 times their own weight in a any one day.
So, from our perspective, you can have your plants and eat them too.
If your compost area has a border around it that is inhospitable to slugs and snails, they are unlikely to leave and declare war on your vege patch.
Coarse sand, harsh bark mulch or copper wire around the bin will help keep them in their place.
In your garden they will always prefer fleshy foliage and stems and just about any seedling they can get their slimy mouths or foot on.
Some popular methods of control that we have tried are:
1. Beer. They simply love a drop of the amber liquid and, like many Aussie's, can smell it from 500 metres away.
1/3 of a glass placed near but not with the vegetables will encourage them in. Easy to get in but not quite so easy to get out.
2. Egg shells
Now, we tried this with broken shells but found that it was a bit hit and miss. Then we washed and crushed the eggshells creating lots of sharp edges over a larger area and the perimeter worked much better.
Sand does keep them away but you have to have a generous border that will not retain water as the water will simply create a skimming medium for them.
4. Predators, like frogs can help a little but the most effective predators are the birds if they feel comfortable wandering through your patch.
Collected seaweed (dry) can, strewn around the garden but not under the plants, help to dissuade the molluscs and never needs to be removed as it breaks down eventually into useful plant food in the garden.
6. Copper wire or tape
A decent ring of copper around a plant stem will react with their natural moist skin and the current created will act a little like an electric fence.
7. Repelling plants
Like pennyroyal, mint and may of the Alliums like chives will deter them a little but the unfortunate thing about these herbs is that they are only effective if they are bruised or crushed.Snails and slugs do not have a heavy footprint.
8. Diatomaceous earth
can be very useful as well because it dries the mucous that the slug or snail use to create an easy path and will be very discourageing for them.
9. Ducks, Chooks and Geese
are also extremely useful police but unfortunately not possible or practical for many urban or suburban gardeners.
10. Nocturnal Safari
Armed with only a flashlight, bucket of salty water (or drinking water if you wish to transfer your catch to the compost bin) and two spoons to catch them in to avoid getting 'slimed', spend an hour each evening for a week, collecting.
You will have solved most of your problem for quite a while.