electronic slug fence

I'm planning to build an electric slug fence, using 9 volt betteries and galvanised wire. It's the design I've seen on the Internet. Alas I know little of electronics.

I want to build two, one for In the propagation glass house, around a central table (1.5m x 4m). And another outside around a strawberry mound (2.5m x 22m).

What range does this setup have? Will it still work on my large strawberry mound?

Will it short in the rain? If my wires are around 2cm apart, and with only 9v through galvanised wire, my intuition says that the rain would have too much resistance for it to short. I have no idea if I am right.

Is galvanised wire the best choice? Copper is good at conducting, but expensive and will surely tarnish when wet, and reduce its electrocution ability.

Using an non electrified copper hasn't worked well for me in the past.

Cheers for any info!

With the non electrified copper, the secret is keeping it well grounded, and shiny.
For proper grounding, it must be driven into the soil for good contact.
To keep it shiny, just wipe it down with vinegar. Cleans off the green, and oxidation.

I've done copper before by the textbook, but big slugs can and will make it over.

Anyways it's too expensive to do round the 44m perimeter of the strawberries and prop house. The strawberries are also planted through ground fabric so there's no soil available there.

My garden is surrounded by forest in coastal British Columbia. It contains sausage sized slugs. I haven't seen even one on my 1000 sq. ft.hugelkultur mound. Garter snakes and alligator lizards have moved in. Hundreds of pounds of coffee waste have been broadcast onto the surface. I assume that one or both of these factors has stopped them from migrating the short distance to my bed. I can think of no other reason why they are not present.

I'm sure galvinised wire would work well, or aluminium would be even better (but not cheap).

I would try with a 12V battery. Standard voltage, easy to get hold of, rechargeable etc etc.
Then just place a current limiting resistor in series to reduce the current for if and when the wires short out so that it doesn't draw max current and melt the wires.

Did you end up trying it with a 9V battery?