Hey man, always glad to see a fellow Jerseyean on here. I live in Aberdeen about 10 minutes from the coast (Exit 117A), and I've got 2 potted plants in their second year of growth (Chinook & Cascade). I planted rhizomes from freshhops around late May/early June last summer, got a decent harvest towards the end of August, and the bines more or less dried up and died back once the weather turned fall-ish. Once it started dipping to the low 40s and 30s at night, and the plants were obviously dormant (meaning no new shoots pushing up), I cut everything down and dressed the pots with compost/bagged humus. Brought both pots into the garage for the winter, where the temperature does dip below freezing occasionally, but not as severely as outdoors. Potted plants (of any kind really) are more susceptible to cold weather because the pot does little to insulate the roots against the elements. In-ground plants, on the other hand, have the benefit of insulation from the ground or snow (like an igloo). This might have been a real issue with last winter, which was pretty cold, but very short on snow cover. Reddish shoots began in late March, and I dressed them again with compost and got them outside on a less-frequent, deeper watering schedule than 2011 season. Growth was spectacular through June, both plants topping their 10' trellises and another 6' horizontal. Unfortunately, I was less-attentive than I should have been on account of work stress, and the hot, dry summer and water restrictions really stunted the harvest. Plants like water, did you know that? What a crazy, progressive concept. >=O
My own plant negligence aside, the indoor overwintering kept them safe from possible frosty death, and allowed them to get some early growing momentum. If you're able, I'd recommend making arrangements to keep the plants in a garage-type environment, where it is still cold enough to keep them dormant, but not enough to harm them. You mentioned rooftop, so if this is an obstacle due to living arrangements, you could keep them outside and mcgyver an insulator/cover to protect them. Bubble wrap, tarps, an ex's favorite clothing articles...whatever blocks the wind. A good layer of mulch wouldn't hurt either, both overwinter and in season (I use cedar, repels some bugs).
Slightly off-topic, but important: Depending on the size of their current containers, consider a significant space upgrade for the 2013 season. My pots are ~2 ft across and ~2.5 ft deep, and it felt like the roots filled every bit of area, and were probably overcrowded this season. Home Depot has enormous half and full whiskey barrels, which besides looking freakin sweet allow ample expansion room. I suspect this limited my own yield considerably, so my second year crop is like 1st year for Cascade, and to date non-existent for Chinook.
I hope this helps...sorry for the long-winded reply, but our setups are very similar, so what works for one prolly works for the other (plus I need more better-quality posts!). Feel free to message me if you have other questions, or wanna compare notes. Best of luck.
-Randy
