My rooster was getting frostbite regularly until I started rubbing vaseline on his comb and wattles and bought the heat lamp bulb. It's one of those really big red heat lamp bulbs people put in their bathrooms. It's 250 watts and just goes into a regular (but not plastic) socket. It cost me about $10 and has been well worth it. I only run it at night when it's below -15 and the odd day when it is that cold all day. The vaseline helps a lot too. He struggled fiercly until I started stroking his comb with the vaseline. Then he got really still and just stood quietly though the whole procedure. I think he likes it. I've done it a few times. It's necessary anyway, whether he likes it or not. I laughed the first time, as one of the lead hens came up really close, watching, and asking a quiet question. When she got in his face he gave her a little chirp without moving and she went away. I guess she was worried. It was so cute! I remember that about Thunder Bay. The things that do grow well there get HUGE due to the extra long daylight. The blackflies and mosquitoes are fierce but only for a very short period of time, then nothing. They get so bad in May they drive the moose out onto the highways. I saw my only real life bald eagle up north and up close. I actually had to use the break to keep from running into him with the car. He was flying down the highway in front of us. HUGE and gorgeous bird with a wingspan much larger than our car. I had no idea they were so big! I never have the camera when I need it!

I would consider them definitely borderline in zone 7, perhaps even to zone 8......they are certainly tricky to grow in MY zone 8. In addition to the cold hardiness issue, excessively moist winter soils would have a limiting factor. Like agaves, to which they are very closely related, this is plant that can often tolerate some cold temps but a combo of cold AND wet for any extended period may be fatal.

dedtired, I checked out Dukestown and found that is part of the old iron working town of Tredegar in Monmouthshire, probably so called after the then local land owner the Dukes of Beaufort. Today the place does not have much going for it after all the closures of the mines and heavy industry. A run-down area of high unemployment with all the problems that brings. However the countryside to the North, known as the Brecon Beacons, is very beautiful in a rugged sort of way, with farms in the lowlands, lots of streams and small rivers, tiny villages and lonely farm houses. You can read about the general area in the fiction of Alexander Cordell; the best known is The Rape of the Fair Country set in the time of the Industrial Revolution. In this area of South Wales there are a series of 'valleys' running generally from N to S. The roads follow the same pattern as do the narrow rows of houses. The people seem to have little contact with their fellows in the next valleys to the E or W. It used to be a place of gaunt-looking chapels for a Sunday, Male Voice Choirs and brass bands. And the women rule the roost! The Tredegar/Dukestown valley is the 'Sirhowy' named after the river which runs through it. Here is a link that might be useful: info on Cordell and the area.

I have been eyeing this thread since it started in hopes of gaining knowledge for next year. I'll add my 2 cents: I started my tomato seedlings in flats in a greenhouse in late February, moved them to large pots (quart yogurt tubs, small coffee cans, etc) in early March, and planted out in the first week of May. (They ended up being a little long in the tooth, I mean stem: I will start several weeks later in future. I had to deep-plant most of them.) Anyway, I noted that the forsythia was starting to bloom when the tomatoes had been in their pots for about a month, and they did look like they were reaching a respectable transplant size at that point. But there was a lot of weather weirdness forecast, so I did not chance it and instead stuck to my family's tradition: plant on May Day. What I noticed was: this was right about the time that the forsythia was going *out* of bloom. There was not another frost, and every tomato established well. Perhaps the *end* of the forsythia, rather than the beginning, is the tomato indicator. And I picked my first tomato on June 12, and have been getting about a pound of fruit a day for the past week. (Mind you, I have close to 50 plants, so this isn't at all impressive! They are just outliers of the main deluge I anticipate. But it will be enough for our cookout hamburgers this Monday!)