Hey mate,
Wish I had space for a poly tunnel, would be great and nice and stealthy

Wish I has some Passion #1 too, they're seem quite hard to get hold of online without spending £££s.
I'm a newbie myself so most of this is second hand info but comes from a wealth of UK420ers experience. General consensus seems to be don't give your plants any food until they look like they're starting to need it, e.g. lower leaves going pale or yellow, but this probably won't be for a while if you're plants are fairly new. Have a look at
OT1's advice here for some good feeding tips. Are they in the soil or in pots? If they're in the soil have you dug in any fertiliser, if they're in pots what compost are you using, it's handy if you can put this info on your profile.
From what I've read you should be able to flower the Passion #1 fine naturally unless you're right up north. If you force them they will finish earlier but with lower yield, however this will minimise the risk of any budrot. Hopefully someone with some Passion #1 experience will be along soon.
Good luck with the grow

Edited because I'm an eejiit