this is an extremely delicate plant... ALL DANGER OF FROST MUST BE PAST ....

for me in zone 5.. that is the last week of may ... not nearly a few weeks away ...

if you are in suburbia ... you may be able to push the date a bit ...

but you can usually just cover a small planting if you religiously watch the weather... and cover over night to protect tissue freeze ..

so i suggest you have 6 to 8 weeks to go to be safe ...

but in the mean time.. you can root a couple hundred plants to share with your friends .... take a one or two inch cutting.. root in water.. then plant into a flat of clean soil ... keep the humidity up.. and in these 6 weeks.. you can have fistfuls of free plants to share ...

good luck

ken

oops.. hardening off.. the actual question.. lol ... start about 2 weeks early ... in the shade ....

first harden off for temperature... returning indoors if real cold is predicted .... then a week or two exposure to the sun ....

faster ..... slower... up to you ... ken

Thanks for the info, Ken. We're going to have about a week of night temps in the 40's and day temps in the 60's, so I'll let them spend a little time out in the shade each day and bring them in at night "just in case". I've already taken cuttings off of the plants I'm going to put out, so if I do them in, I'll have back up plants. Thanks again for the reply.

Hi i put them in cardboard boxes and leave them out side all day and bring them in a about 7 at night that way even if it get windy they are protected it been at least 3 years and it works will i have now over 55 different plants plants Anna lisa

I tried putting perennials in my unheated GH,and they did fine.Then just to see if annuals would tolerate this I put one coleus out there.Poor little thing,dead as a doornail come morning,so they won't tolerate,any temps close to freezing.Well at least I know now.

The rule is do not plant coleus outside until soil temperature measured in the morning is at least 55 degrees. Al

Thanks for all the input. I've left them out for a couple of nights that it's been in the 40's...tonight I brought them in, as it will be in the 30's. They seem to be doing ok. I just have to keep remembering since our apartment is on the opposite side from where I've been putting them out.