Passionflower (Passiflora incarnata, Passifloraceae) is a short-lived perennial native vine to the southeastern US, with gorgeous flowers and interesting foliage. It is weedy in much of its native range; and fairly easy to grow elsewhere, especially if its given a wall or trellis to climb up. The leaves and flowers are an important nervine sedative and are used to help promote sleep and alleviate pain, such as menstrual cramps and headaches. Following are some important details on saving passionflower seed and its germination.
Pictured below is fermenting passionflower seed pulp. Many fleshy fruits have germination-inhibiting factors in their pulp, and the seeds will not sprout unless they are cleaned free of these chemicals. In nature, the elements will take care of this process, as will the hydrochloric acid in the stomach of a seed disperser (imagine a little box turtle eating a maypop and pooping the seed far from the parent plant, cleaned free of the pulp, and amended with the nitrogenous gold of turtle excrement). So, how does one mimic the digestive processes of a box turtle, or twenty-three snowstorms for that matter, when one wants hundreds of passionflower sprouts? One enlists the help of the invisible, yet omnipotent.
Put the seeds in some water, cover with a porous cloth to keep out the fruit flies, and let the omnipresent bacteria and fungal spores have a party in your favorite crock or mason jar. After 3-5 days wash free of pulp and if all the pulp isn’t gone, add fresh water and repeat. Eventually the fermenting mush will just be seed, which you can dry and store until spring planting, or plant fresh if appropriate. You can use this technique with the fruits of spikenard, blue cohosh, tomatoes, jack in the pulpit, and ashwagandha as well.
Scarification – Many seeds have a thick impervious seed coat that must be nicked or cracked before the seed can germinate. You can rub the seeds between two pieces of sand paper until you see a little bit of the endosperm (embryo nutrient reserves, usually a lighter color and different texture than the seed coat). Sometimes this is done before stratifying seeds and sometimes at the time of sowing. Astragalus, wild indigo, hollyhock, licorice, marshmallow, passionflower, red root, and rue are some of the herbs that will germinate better with scarification.
Passionflower germinates in warm temperatures (70 degrees F plus) and can be transplanted when it develops its "true" leaves. Hold on to your seed tray as it will often continue to germinate over time.
Pick your fruit when it begins to turn yellow and the seeds are hard and black. If the frost is coming before the fruits are ripe, pick them all and put them into a closed brown paper bag for 1-2 weeks to let the seed mature. Break them open, scoop out the pulp and begin the fermentation process, described above. The pulp surrounding the seeds is edible and delicious!