The passion flower is actually a vine that grows in partially sunny areas and in somewhat cool temperatures. It does not like to be in direct sunlight and will probably die in frost-prone areas. You can start passion flowers from cuttings if you happen to have a vine nearby or simply use some of the seeds from a passion fruit.
Take the seeds out of a fresh passion fruit and rinse them clean. You do not want the flesh of the fruit to rot and introduce mold into the germination pot. After cleaning, place the seeds in a paper towel to dry.
Scarify the seeds by rubbing them with sandpaper. This will help the water to get through the seed coating and allow the seed to germinate. It is possible that you may be able to skip this step, but you want to give your seeds every chance to sprout. Start with at least three or four seeds for each container.
Dampen your potting soil and bury the seed just under the surface of the soil. Tap it down lightly to make sure there is good seed-to-soil contact. Sprinkle water over the surface of the soil and place the whole container in a plastic bag.
Place the potted seeds in a warm place where the temperature stays a constant 80 degrees for at least two to four weeks. By this time, the seeds should be sprouting. Remove the plastic bag so the moisture levels drop a little to prevent mildew or mold.
Thin out any extra seeds that sprouted. Pick one healthy sprout to survive per pot. Set the seedling into a warm environment where it can get indirect sunlight. Once it is over 6 inches tall, you can transplant it to a permanent area in your yard.
Take a 3-inch cutting from a growing tip with a few leaves. Cut it with a sharp knife just below the leaf. Remove the bottom leaf and dip the cutting in rooting hormone.
Push the cuttings into a plant pot filled with the same kind of potting soil as used for the seeds. They only need to be about 1/2 inch deep and you can put several in one container.
Cover the cutting container with a plastic bag and place it in a 70 degree spot such as a warm and sunny windowsill. Punch a couple of holes in the plastic bag to allow a little air movement.
Remove the plastic bag after a couple of weeks or as soon as you see signs of growth. Allow the cuttings to develop a few leaves before transplanting into individual containers. After about 12 inches of growth the plant can be transplanted outside or, if inside, to a larger pot.