You can plant Moon Vine (Moonflower) any time after the 15th of March in our zone.

Soak the seeds overnight in water for increased/faster germination.

Yep, I planted mine a couple of days ago. I seem to get a lot of leaves and very few flowers on these...I don't fertilize them. Anyone know what they like?? Really cruddy soil maybe?

me too! last year i had a lovely vine, mostly sun. it went mad with leaves all summer, but i got a total of 2 flowers. beautiful, huge, but not enough of 'em. i didn't enrich the bed and it was root-crowded, but...ideas?

I grew some a few years ago when I was living in Valdosta that was planted in full sun(all day), sandy soil with lots of natural compost and it grew and flowered like mad. I had a fence that they grew on...about 15 feet of vines. They came up very slowly then really took off when it got real hot and humid. I think it was late in the summer before it started to bloom. The blooms would happen suddenly at dusk and stay open all night into the early morning. At around noon everyday I would find the blooms on the ground! Very short flowering! But incredible size (6 inches across) and smell. That evening new bright white blooms would appear which glowed from dusk to dark. You had to fight with the bees and hummingbirds to smell them. I suggest well drained soil in the hottest part of the yard and then just forget about them. I have not tried to plant it here in the north ga clay.....but may this year.
As a note it will re-seed itself.

I have never had a problem with moonvines flowering enough. I never fertilize them. I usually plant them where they can scramble on the ground or over a wall. Maybe neglect is the best thing for them!
I started a couple dozen in peat pellets 10 days ago; they are coming up now. But I'm sure they are OK out in the ground; I've had them come up from seeds that got left in the previous year's growing spot.
I scarify the seeds (cut a scratch in the seed coat) and soak them overnite to give them a boost.