Passiflora Manicata Red Passionalflower vine in bloom.
image by John OCampo:commons.wikimedia.org
Red and scarlet passionflower, known botanically as passiflora manicata and passiflora coccinea respectively, are flowering and fruiting tropical perennial climbing vines native to South America. Red passionflowers can be germinated from fresh good quality seed when started in pots indoors or directly in the garden soil and kept warm. Hardy in USDA zones 7 through 10, they prefer full sun with afternoon shade during peak heat and moist rich soil.
Select a site to plant your seeds either indoors or outdoors where you can maintain a consistent temperature of 79-degrees Fahrenheit through germination. Alternatively, provide 8 hours of 86-degree temperatures and 16 hours of 68-degree temperatures daily. After germination, when small white shoots are visible, provide daily temperatures that hover between 60 and 70 degrees Fahrenheit.
Prepare a seed bed for your fresh red passion flower seeds as soon as you receive them, as they do not store well and the failure rate increases with age. Use a well drained compost or a bagged commercial seed starting mix as a germination medium. Scarify the seeds to speed germination by abrading them between two sheets of fine sandpaper and soaking them in room temperature water for a day and night before sowing.
Bury your prepared seeds 5 millimeters deep in the moist compost or seed starting mix. Plant multiple seeds to increase the odds and speed of germination as plants can be thinned at a year old or so. Water in lightly so that the soil is not washed off the seeds. Keep with the proper temperature needs and your red passionflower seeds should germinate in four to twelve weeks. You will see tiny white or pale green growth break through the soil crust. Some seed may take up to 48 weeks to germinate and grow shoots so don't get discouraged. Grown from fresh seed your red passion flower should begin to produce bloom in 2 to 8 years.
Feed your red passionflower vine seedling only after there is 6 inches of green growth and true leaves have started to form. Thereafter, feed regularly during the heaviest growing season from spring through summer. Choose a good quality general purpose formulation that includes significant levels of potash. Apply according to the manufacturer's dosing instructions over pre-watered soil to prevent chemical burn and speed the absorption of nutrients.