The passion flower, also called Maypop or Passiflora incarnata, is native to the Southeastern United States. Its flowers are 3 inches in diameter and bloom from July until the first frost in autumn or early winter. The flowers grow on vines that can grow up to 15 feet long in a single growing season. The scarlet passion flower grows well on trellises and fences, and grows best in USDA Zones 5 through 9, so it's hardy down to about -15 degrees Fahrenheit. The flowers produce oval berries that are edible fruits, used to make jams and jelly.
Select a planting site in partial to full sunlight that is somewhat protected from frost or severe cold winds. Passion flowers are readily adaptable to most kinds of well-drained soils.
Plant your scarlet passion flowers in early spring, after the danger of frost has passed. Till some organic compost into the planting hole.
Water the plants once per week throughout the growing season to keep the soil moist. Feed your scarlet passion flowers a 10-5-20 fertilizer in early spring and again in 6 to 8 weeks, following the dosage instructions on the package.
Spread a 3-inch layer of organic mulch around the passion flower plants in autumn to protect them from severe cold.
Propagate your scarlet passion flowers by taking softwood cuttings from mature wood in early summer. Or, harvest the seeds in early autumn to propagate the plants.