How to Grow Passionflower (Passiflora incarnata)
This article is part of our “How to Grow Herbs” series. If you would like to learn more about how to work with herbs after you harvest them, please refer to our Herbal Aromatherapy Certification Program™ here.
Passionflower is like the art gallery of the garden for me. Its blooms are so intricate and so entrancing that I sometimes want to just sit and look at them, mesmerized, for hours. The bees in my garden love them too. I have found that even the bee species that tend to be home before dusk will linger in my garden to play in the passionflower plants well after their usual curfew.
The species of passionflower that is grown for therapeutic use in the western herbal apothecary is Passiflora incarnata. This is the one we will be discussing today.
Growth Habit
Passionflower, sometimes called maypop, is a vining plant that needs to be well trellised as it grows. It is perfect to plant along a fence, as the vines can grow to be up to 25 feet long in ideal conditions and training them horizontally along the fence can be a great way to maximize space and allow for easy harvesting of fruit.
Hardy to a USDA growing zone 5, I have found that passionflower is one of the very last things to wake up in my zone 8b garden each spring. Usually right around the time when I start to think that the plants died over winter and need to be replaced, they are just getting ready to sprout up through the soil again with the year’s fresh vines. If you live in an area that is colder than a zone 5, you can also grow the plants as annuals.
In spring, passionflower plants produce round, intricate, purple and white blooms. If left unharvested and pollinated, these blooms develop into delicious passionfruits that ripen about 2.5 to 3 months later.
Growing from Seed
Passionflower can be a little bit finicky to grow from seed, but it is doable. I tend to sow extra seeds in case of uneven germination and have found that a combination of scarification and soaking tends to work best. You can sow the seeds in flats or you can fall-sow them directly where you want the plants to grow if you live within passionflower’s hardiness zones.
Before sowing, nick the seed coat of each seed with a bit of rough sandpaper. Be gentle; you do not want to break the seed, only to damage its protective coating. After doing this, place the seeds into a ramekin or bowl and cover them with warm water. Let them sit for at least 48 hours before placing the seeds into the soil. Cover with a layer of soil about as deep as the seeds are large, then water in evenly.
Keep the seed tray in a warm area and keep the soil moist until the seedlings emerge. Once you have a few sets of true leaves on your seedlings, you can plant them out into the garden.
Growing Conditions
I have found that passionflower grows best when planted in full sun with adequate spacing and well-amended, deep, well-draining soil. While you can plant them with as little as 36” between plants, because the vines can be so vigorous, you will likely find that they are healthier when given 60” of space between plants instead.
Train the young plants onto the trellis as they grow to help keep the vines under control.
At the end of the growing season, the plants will die back to the ground. Cut them at ground level, top dress them with a thick layer of mulch, and wait for them to emerge again the next spring. Alternatively, if the plants are not hardy in your region’s winter temperatures, you can dig up the plants before the ground freezes, place them in soil in a large pot or grow bag, and overwinter them in a garage or otherwise protected area. Replant them in the spring.
Learning More
If you would like to learn more about how to work with aromatic plants, I hope you will join me in our Herbal Aromatherapy Certification Program™ here at Floranella! In it, I teach students how to safely and effectively work with over 100 different herbs as well as their applicable essential oils and hydrosols from the garden to the still to the apothecary. I hope to see you in class one day!
About the Author
Hi there, I’m Erin! I am the main instructor here at Floranella. I am a clinical herbalist, aromatherapist, artisan distiller and organic gardener based in the Pacific Northwest. Here at Floranella, I teach people how to work with plants safely and effectively from the garden to the apothecary. Thanks for being here! I’m glad you stopped by.
