If you are talking about moon flower that is in the bean family, with a bean shaped seed, I would be comfortable planting some now. Since the weather has finally warmed, the seeds will sprout quickly and plants will take off. My seeds that were planted several weeks ago are just now beginning to run. I usually plant mine in small pots, then transplant to gallon pots and then plant them in their final destination. But have also direct seeded them with good success.
Eclectic gardening style, drawing from 45 years of interest and experience. Mostly plant in raised beds and containers primarily using intensive gardening techniques.