Imp
Lifer
I assume you mean "weak", and not "week", as weed generally takes 8-12 weeks to bud. Outdoors, it always buds in the fall. So yeah you can plant it in your garden and it will grow. As long as it doesn't snow where you live, you should be ok. Frost is OK.
When grown outdoors a good strain will lose some of its potency. You will never see >25% THC outdoors, the conditions just don't exist in nature to grow it like that. It will still retain the majority of it's potency as long as it was grown in good sun and was watered regularly and sprayed.
Woops... I meant weed like a weed, as in would it go batshit crazy and grow everywhere destroying everything else.