Basically, you want to start growing them after the last frost, which can be hard to predict. I would say late April to the middle of May would be a good time to start growing, but I do not live where you do. So whenever it starts getting warm and keeping around the same temperature would be the best time to grow. I would not recommend ordering seeds from the internet. If it's not a scam and it's legit the site could be found by the fuzz then you are basically screwed since they will have all the information on who has bought what.
Nirvana are a straight company nice plain wrapping very hush hush and good selection of out door seeds. Even offered me replacements seeds when some failed.
Soz try www.nirvana-shop.com/ There in holland and they source from breeders and do there own breeding so there good on prices too.
