I'm in zone 5a, having the same thing. I don't worry about taking brugs in till 36 starts to be a reality. I have 6 to dig up so I'll have to work fast if it comes as a surprise.

It is more the risk of frost than the actual temps between the 32 and 40 degree mark. They are not at all frost tolerant but draping a blanket or anything but only plastic over them for light frosts will give you a little longer before having to bring them in.
Even those of us who has grown them for years can get caught when they are too tall to try covering them LOL. If the foliage gets frosted, you can cut them back and still save the root systems.

Sad, frosted look....
{{gwi:546443}}

Yikes , yes that is sad looking. Ok so I should get it in before it goes below 40 then?

Mary

If you are waiting to see buds become blooms, I suggest you leave it out until your temps get into the lower 30's as long as you can cover it with a blanket or sheet if you have a frost warning.
If not waiting to see blooms, go ahead and pot it up and start removing the lower leaves to compensate for the reduced root ball mass. Here I used to pot mine up in mid Sept. and allow the soil to dry some before bringing them in early Oct.

I would suggest you pot it up since you're going to have to do it sooner or later anyway! Brugmansias are pretty stubborn plants and there's a good chance the buds already on them would still develop, just as long as you keep them watered in pots.

If you are really good at watching weather forecasts each evening, the magic number is exactly 32 degrees, and in my experience even a few degrees above that won't affect them (except slow the growth a little). Also, I'm not sure but it seems as though cold temperatures may trigger more vigorous blooming. But in your situation... you don't want to be realizing at 6pm it's going to freeze that night and have to be running outside digging your plants up in the dark. I'd just dig them up and keep them in pots for the rest of the season.

As a side note, I have had brugmansias continue to bloom in pitch black in the garage where we store them for the winter, for at least 2-3 more weeks after bringing them in. The flowers came out successively smaller and paler but they continued blooming as the leaves dropped off. Finally the plant went dormant and sprung back to life in the spring as usual. But they may go all winter in a South-facing window or for a month or so in a less-ideal window, depending on how lush they are now.

These are EXTREMELY tough plants and seem to never die; they can freeze and look dead, but come back from the base, or they seem to have dried out accidentally over the winter, but they come back from lower stems, or they get wiped out by spider mites and all leaves are gone, but they come back... they can go through several "disasters" in succession and still re-generate. You just can't kill them.

Ain't that the truth, I thought Miss Mackenzie was a gonner when she arrived all wilted and dropped every single last leaf she had. LoL By gosh she came right back like a champ! The double yellow Datura hasn't recovered nearly so nicely. :) But I expect it will eventually. I had to spray naturally IE soapy bath type wash, for mites on the datura. But everything else is doing just fine. Both Brugs Bill sent me are doing wonderfully well. :) I plan to take photos of the brugs and my hoyas this weekend so I'll try to get those up and share them.

~Tina

pizzuti, what growing zone are you in?

^I'm also in zone 5.

It might be a different "kind" of zone 5 than you experience in Canada. I'm in Colorado, much farther South but the winters can get cold due to dry air and high altitude.

That makes the temperature more variable... so there will be cold snaps in the fall, winter and spring that put us at zone 5, but also very warm days in the middle of winter, which you might not have.

Our first frost can range year to year from early September to late October. And if you protect your plants with blankets or plastic from an early frost, in our case, they might have 2-3 weeks before the next one.

As for Brugs, though, I think we've always brought them in sometime in mid to late September, and put them back out at the end of May. Interesting to see a tropical plant be able to be dormant for a longer portion of the year than it is not dormant.

Guys if you decide to trim down your brugs, will you please share the cuttings with me? I can pay postage please let me know, here in Texas we are still having pretty hot days next week we will be in the 100's again! Please let me know Thanks Marcie