vegetable patch management
pest control
DYNAMITE - snail pellets

The category of Dynamite refers to a range of stronger pesticides that, while being very effective, have potential long term side effects. I believe that pesticides and herbicides in the Dynamite category should only be used as a last resort (having exhausted the Defend options) or as an stop gap measure while you are setting up your vegetable patch using Deter principles. A well planned and established vegetable garden is less likely to need pesticides listed in the Dynamite category.

metaldehyde snail pellets
Very effective at killing slugs and snails and are one of the most common pesticides used by gardeners.

The active ingredient in them is Metaldehyde. The World Health Organisation classifies metaldehyde as a ‘moderately hazardous’ pesticide. While it is relatively safe It can be quite dangerous if eaten by humans or other animals, such as dogs. Birds eating slugs and snails poisoned by snail pellets may also be at risk. While I could not find any information on whether long term use of snail pellets can contaminate soil I think it wise not to leave them to break down in your garden.

If you have to use Metaldehyde snail pellets then place them in a removable container. Commercially available snail trap containers such as the ones displayed on the Fermented Sugar Trap web page are ideal. Not only do they stop pets such as dogs from eating the pellets they also keep the pellets dry, which will make them effective for a longer period of time. Snail trap containers also stop the pellets from mixing with your soil.

disposable tin can snail traps for metaldehyde snail pellets

A. Fold the lip of one half of the can over to form a small ridge.

B. squash the other half of the lid down so it forms a narrow entrance.

C. Add some snail pellets and place the tin in a small hollow in the soil so that small ridge is at ground level.
A cheaper alternative to commercially made snail traps is to make your own using tin cans. To make a tin can snail trap you :-

A. Using pliers fold the lip of one half of a tin can over to form a small ridge.

B. With the heel of your foot squash the other half of the lid down so it forms a narrow entrance.

C. Add some snail pellets and place the tin in a small hollow in the soil so that small ridge is at ground level. It should be placed in a position so that slugs and snails can enter but the pellets will not get wet if it rains.

If you like you can also make a hole at the bottom of the tin to allow any water that might get into the tin to drain away. The best way to make a hole is with a can opener.

The main disadvantage of tin can snail traps is that slugs and snails can only enter the tin from one side, where as the commercially available snail traps offer 360 Deg access. As well as snail pellets tin can snail traps can also be baited with a Fermented Sugar mixture.

If you have to apply metaldehyde snail pellets directly I suggest you lay them out along the paths next to the vegetable beds. So when pellets begin to break down they can be swept up and removed. One pellet every five or six centimetres is plenty. Commonly people put far too many snail pellets out.

However with the fairly recent advent of Iron Phosphate Pellets I would argue that there is almost no need for anyone to use Metaldehyde pellets anymore.  While Iron Phosphate pellets are not quite as effective they work in very similar ways to Metaldehyde pellets and are much safer environmentally. 

If you have any Metaldehyde pellets left I would suggest that you use them up in the manner described on this webpage and then switch to Iron Phosphate pellets.