Best recommendation is a week or so, but I've left them out for a month or more under a tree in cooler weather and they were fine. They aren't cold hardy at all, in fact, they don't like being below 40 degrees, so put them in a protected place this weekend when it gets cold, like a garage or inside. They're relatively easy to root. If I had a bunch in our zone this time of year, I would stick them all into big pots and sort them out in the spring. You don't actually need rooting hormone on them, and they will take awhile to root this time of year. My only caution is not to overwater them, in fact, keep the soil relatively dry so they don't rot. Good luck!

Thank you :-)

I had I got some in the mail last year late, when it was too late to root them. I kept them in a tray, laying flat in some perlite. They didn't root, but they didn't rot either. By spring I think I had sprayed them once or twice with a water bottle because they had started to wrinkle and shrink from drying out. They always plumped back out again. They rooted promptly come spring when I planted them. All told they spent four or five months sitting in that tray. Got down to the 40s too.

Plants are amazing! I had cut some crown of thorns back and tossed the cuttings under an oak tree once and forgotten about them. Leaves covered them in the spring, and that summer, I found them when I went to clear an area out to put down blocks. They looked dead, but at the top, you could see it was still green, so I stuck them in the ground and they rooted. Same thing happened to my yellow Thai COT here that literally died from root rot. I tossed cuttings into a pot with no soil, and when I saw green coming out of some of them, I stuck them into pots. They are growing out there now, and I have one growing in the ground as an experiment to see if it survives the winter.

Wrap the cuttings in newspaper and put them in a cool, dry place until April. Then follow the directions for rooting on plumeria 101.