First thing,
you will be able to find weed all over in the switzerland.
Second,
if you got an uncle in St. gallen, in St. gallen there's also a little growshop who sells whole plants so sure you will be able to find there some people they know where to get some..
Third,
I give you one recommendation for traveling FRIENDLY stoner places besides the NL - Prague!
Not sure how far the latest informations about it travelled, in the CZ there's (everything) (legal) to a point of so and so much g depend on what drug you got. Also Heroin is (legal) to buy and travel around with it up to 1.5g or something (!) And if you're know anything about CZ, especially police there, give'em 50e, you could go on with everything, sometimes more, sometimes less but try every time you got problem with them!

You could buy weed in bars at the toilet, there's some groups taking the whole city business, turkish, blacks and i thought about some locals mixes.. the last one are the bests to get from. And of anybody whos thinking now i'm only talking, my mates saw there children with 14 years on the main center station of prague fixed them H on a little green place at the ground in the front of all people and nobody sayd anything or stopped.. i don't wanna say it's good or not at this point, its only for information.
And at least,
take your bags, take your time, save your money and dont leave the train in germany! Still so long till they're chance they're position about cannabis in the politics
german wide! Berlin doing ok with it now and do it seperate to all other cities in D, but that couldn't be so i please you to not give'em on cent of your money for theyr fucking closed minds! All country's, ok, france is another thing, around germany are ok on cannabis at least as it is in belgium, up to three plants or something per person will be no case of any worries. In parts of germany you will be fucked deep in your ass for 1 or 2g (!)
And sure i know what i'm talking about
Happy travelling!