Since vanilla is very tropical, loving heat and humidity to succeed, then growing it in your zone it will require, as your topic suggests, a greenhouse.
The flowers, each of which lasts only one day need to be hand pollinated and there is a trick to that.
The vines won't flower though until they reach the top of what they are climbing on, can climb no higher, and the vine ends 'fall over'. That triggers flowering if all other conditions are right.
Once the flowers have been pollinated (a daily ritual while the vine is in bloom) it takes a while for the vanilla 'beans' (seed pods) to mature and then they must be carefully processed and allowed fo slowly ferment. There is information about that whole fermentation process online.
Good luck!
Paul M.
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