Dorothy is a Master Gardener, former newspaper reporter, and the author of several books. Michael is a landscape/nature photographer in NM.
Intriguing, Gorgeous Flowers, But...
A passionflower is stunningly ornate, has five petals, and a very distinct corona. When it ripens, you will be rewarded with a delicious fruit that has a lot of seeds that you can use to propagate more plants. The striking color pattern makes the passion flower a very unique flower specimen, and there are hundreds of different passionflower species that are all ecologically intriguing. That's the good news.
It may be hard to believe that something so tropical looking and beautiful could be invasive, however, but that is sometimes the case with passion flowers as they send up numerous sprouts from spreading underground roots, so read everything you can before you decide to grow your own.
If you do decide to proceed, there are several different methods for propagating a passionflower—planting a seed, taking softwood cuttings, layering, rhizomes, or you can purchase a plant from a nursery.
Consider Growing Passionflowers in Pots
You might be better off growing them in pots where they can be somewhat controlled, rather than in your garden where the rhizomes are free to spread at will, which explains the invasive part. Growing them in containers will allow you to move them to a sunnier site when necessary, then bring them indoors for the winter.
Most people say that passionflowers really do well in containers and most varieties are considered hardy perennials in USDA growing zones 6-10. But in cooler zones, they must be brought indoors for the winter, or they won't survive. Even in zones 6-10, they need some winter protection, such as mulching (the colder it is, the more you mulch). Plus, as winter approaches, stop any fertilizer that you are using so that new growth will be discouraged.
The part of the plant that is above the ground will die off in the winter, but the root system should be intact (if you are in a warmer climate, even the part above the ground may be fine during the winter months).
Rooting Passionflower Stem Cuttings
If you are going to propagate using stem cuttings, they are usually taken during the softwood stage, because they can break off easily when bent. Using a sharp, sterile pair of clippers, cut just below the node some four to six-inch cuttings.
Afterward, strip away the bottom-most leaves and tendrils on the cutting. Dip the ends in rooting hormone (I always use Garden Safe TakeRoot Rooting Hormone) and stick the cuttings into some well-draining potting mix (I suggest Miracle Gro). Each cutting will need to be placed at least a half an inch into the soil. You can also use an equal mix of sand and peat if you prefer.
Water the cutting lightly and cover with a clear, ventilated plastic bag, applying stick supports if necessary to keep the cutting in an upright position. Your cuttings will need to be placed in a shady location where they can be kept warm and moist.
New growth should be seen within a month or so, and you can at that time give a gentle tug on the cuttings to see if their rooting system has been established. If you tug and there is some resistance, you have likely gotten significant rooting and the cuttings can be transplanted to their permanent location outdoors.
Blue Indigo Passionflower
Growing Passionflowers From Seed
If you have some fresh passion fruit and want to grow your own passionflowers, you can cut open the fruit of the plant and the seeds will be in the middle, but they will be covered in pulp that must be removed by soaking them in water. You can put them in a large jar and cover it with a porous cloth to keep flies at bay.
After a few days, wash the seeds. If the fermentation does not cause all of the pulp to wash away, add fresh water and repeat the process until you have only seeds left with no pulp. Dry the seeds and store until you are ready to plant them. Keep in mind that the longer they are stored, the less viable they become.
Each fruit can contain up to 250 round, black seeds. When you do plant, sow them only about a quarter of an inch in potting soil.
You can also buy passionflower seeds. But be careful to buy them from a reputable seller and make sure you are buying fresh seeds that were harvested very recently.
Passionflower seeds are very slow to germinate; they have a hard outer coat and are very slow to absorb water. You can accelerate the germination by using a process called scarification, which will physically weaken or actually break the hard seed coat. This will allow water to move into the seed more easily, but this method requires you to scratch the surface of the seed using either a sharp knife, razor blade, or small nail clippers prior to soaking it in water.
Harvesting Seeds From Passion Fruit
If you harvest seeds from passion fruit that is not yet ripe, they will not germinate, so don't pick the fruit from the vine. Instead, allow the fruit to fall to the ground, which will ensure they are ripe. Once you have the fruit collected:
- Place it on a tray and allow it to ripen for another two weeks, during which time the fruit will begin to ferment, a process that will kill off Fusarium spores (a fungus that can cause seedlings to rot).
- After the fruit has ripened, cut it in half to reveal the seeds, which are coated in an orange-red jelly-like substance.
- Place a straining utensil in the sink to catch the seeds, then wash them under cool running water, which will remove the gel coating.
- Put the seeds in a glass filled with lukewarm water. The seeds that float in the water are not viable, so discard them. The remaining seeds should be left to soak overnight in order to soften their hard coating.
- Dry all of the seeds with a paper towel and sow them immediately, as fresher seeds germinate more reliably than seeds that have been stored.
Propagation by Layering
Layering is usually done in late summer by stripping the leaves from a small section of the stem, bending the stem over, and partially burying it in the soil. You may need to anchor it in place using a small stone. Water it well, and it should begin rooting within a month or so.
For the best results, keep the bent stem in place throughout the fall and winter, then remove it from the mother plant in the spring.
Passionflower and Passion Fruit
The Fruit of a Passionflower
The core of the passionflower fruit is packed with seeds, and the fruit itself is about the size of a small egg. The flesh of the fruit is edible and delicious, and the smell is heavenly and fruity. Because the pulp is sweet, it is often used in various jams and beverages.
The fruits vary in color from yellow to purple, but they are all edible. The color will depend upon the species you choose to grow.
This article is accurate and true to the best of the author’s knowledge. Content is for informational or entertainment purposes only and does not substitute for personal counsel or professional advice in business, financial, legal, or technical matters.
© 2018 Mike and Dorothy McKenney