More on Moonflowers
Moon Vine (Ipomoea alba), not to be confused with Datura or Brugmansia.
Some gardening articles recommend nicking it with a nail file, but I use a nail clipper instead. How? I just make a little cut in the side of each seed and then soak them in filtered water for a few hours or overnight.
Rather than planting them in dirt, I put the soaked seeds in a heavy cloth bag and immerse it in water a couple times a day, letting it drain the rest of the time. Since Santa Clause brought me a Sproutman's Hemp Sprouting Bag a while back, I use that. Tap water is not a good idea in many places as the chlorine in it might inhibit growth. That is why I use filtered water.
PS: All parts of this plant are potentially toxic and should NOT be eaten.