Philodendrons and pothos are the first things to come to mind. Or both, they can be grown together.

Do you know what the post is made of? If it is concrete or steel or something that will be moisture proof you could wrap it in burlap tree wrap. With just a few dabs of silicone cement to stick it on_ It would be non-toxic. brownish in color and plants might be able to climb it themselves or with a little bit of help from you (like making some small hooks from paperclips).

I was thinking a Hoya, Hoya carnosa specifically. It likes to wrap around things and is pretty easy to grow.

Planto

link to your pic.

I'm hard pressed to think of a climbing tropical vine that should be used around a bunch of pre-schoolers! Anything in the Araceae family should be avoided around children that young, absolutely. Sorry, that included philodendron and pothos.

Hoya is not supposed to be toxic, but several members of that family exude very irritating sap. Plus, hoya doesn't climb....it hangs.

I can't help but wonder about the logistics of this project. Are the plants going to be growing from pots on the floor? Or what? Just curious as to what the vision is.

I'll keep thinking about some truly non-toxic possibilities.

rhizo_1,
I would have to respectfully disagree on the climbing nature of hoyas. Some hang (such as H. DS-70) and some climb (such as H. carnosa). I have two carnosas and I'm always having to pry them off of something as they wrap around anything they come in contact with and climb up (i.e. table leg). There was a recent post on "Bad [Hoya] Neighbors" and how they invade other plants privacy.

Planto

Here is a link that might be useful: Bad Hoya Neighbors

i agree,hoya carnosa has a climbing habit.i want to say ipomea batatas"margarita"(sweet potato vine. use green garden tape to tie it around because they will fall over

Now that I think of it.....I was always having to spank a large hoya I had for constantly getting tangled up in the wooden blinds.

rhizo_1,
;)

Planto

I used to have a vining plant years ago but I forget its name. It had leaves that were slightly hairy and was a bit like grapevine but smaller. Foliage only. Gonna bug me now...

Lilg, did you come up with some type of plant for your classroom?

When I first read this, I didn't really have any ideas but after thinking about it couple times, it occurred that the vine could be some other kind than a traditional house plant. The black paper taped over the windows is a concern though, blocking most of the light. If there is enough light, a bean vine might be a good project, or sweet potatoes, tomato (or whichever of these wouldn't mind growing in winter instead of summer. I'm not a food crop expert at all. Maybe someone who does know more about these kinds of plants would have even more appropriate suggestions.) BUT the food aspect would be an additional lesson for the kids, and these kinds of plants tend to grow fast enough to be exciting for kids. You could also do a hanging basket and let some parts hang, some parts climb.