I've just started moving mine out, maybe I'm not cautious enough, but I'm ready to start fresh. I've moved out-bird of paradise, ficus, ponytail palm, pandan, hibiscus, monstera, aloe, overwintered begonias, in pots-not showing signs of life yet-dwarf cavendish banana, elephant ears, dahlias...I've done my share of moving things in & out of the garage this spring (mostly containerized Jmaples & newly purchased perennials), but now they're on their own-survival of the fittest! I also purchased tomato seedlings this weekend that I'm moving into earthboxes & the ground.

I can tell you that bananas do not grow below 52 degrees, so not much point moving them out earlier unless you are dying to make room in your house.

Tropical hibiscus aren't crazy about temperature swings, you may get some yellow leaves when it gets chilly, but they'll definitely survive down to 40 degrees with no trouble. But they won't grow much.

I usually go for the first week of May, onto my front porch which has a roof and faces east, so it's a little more protected from sun, wind and possible frost. Most of my plants are so big that I'm NOT moving them in again until fall!

I suppose if you want a rule of thumb, I would guess maybe 50 degree low at night and no lower would be suitable, but I'm sure others have different opinions. If you're really ambitious, you could look up each kind of tropical on the web and see what recommended minimum temps are.

There is quite a range of plants, but watergal is correct in that most tropical species will not grow unless nights are above 50, many will sustain damage to new growth in the low 40's, and almost all may rot if kept moist while cold.

Bananas are pretty tough plants and most will be fine down to the mid-30's, they grow so quick that new growth will cover up any mistakes.

BOP are safe close to freezing, but should be dry. Aloes are definitely safe, most will tolerate frost. Citrus should be OK. Plumerias can get "black tip" disease if too cold, don't take them out until nights are into the 50's. Brugs need cool nights to initiate bud formation, but below mid-40's is risking damage depending on the variety.