Passion Fruit (Passiflora edulis)
Passion fruit growing overview:
Passion fruit plants are fast growing subtropical-to-tropical vines that can produce lots of delicious fruit.
This article is focused on growing the purple variety of passion fruit (Passiflora edulis). However, many of the same principles apply to growing the yellow passion fruit variety (Passiflora edulis var. flavicarpa). The major differences between the two plant varieties will be noted in the article.
Passion fruit appearance:
- As you might expect the purple passion fruit is… well it is purple (at least when ripe).
- The fruit tends to be ovoid in shape and the fruit size ranges from 2-4 inches in length (a bit like a large egg).
- When fresh, the skin tends to be smooth and shiny, but begins to wrinkle in a few days. The skin is thick and tough which is great for keeping out the rodents and birds.
- Inside the fruit, you will find the delicious yellow-orange pulp surrounding many black or brown seeds.
- The yellow variety is… um, well it is yellow on the outside. The pulp is also yellow-orange for the yellow variety and the yellow passion fruit variety tends to be larger in size.
Passion fruit taste:
- Purple passion fruit is delicious but the flavor is rather intense; like concentrated fruit juice.
- The yellow pulp is both sweet and sour with a very distinct aromatic tropical overtone. The tropical element is very distinct/unique but is reminiscent of a sweet guava. The fruit tends to become sweeter when the fruit is slightly shriveled. The seeds are hard and crunchy.
- The yellow passion fruit is more acidic, (more sour/tart), and less sweet than the purple variety. Some say that the yellow variety has an aroma that is less intense than the purple variety as well. The yellow variety also tends to have less juice.
Passion fruit use:
- A fresh passion smoothie is super delicious and refreshing. To make passion fruit smoothie, I blend passion fruit pulp with water, ice and a bit of dissolved cane sugar. The seeds get macerated in the blending process and sink to the bottom. Passion fruit pulp/juice is also a great addition to just about any mixed tropical fruit juice drink/smoothie. the tart passion fruit is a nice complement to sweet mango.
- Some people like to add passion fruit pulp to salads straight or added to dressings for a pop of bright flavor.
- My friend and colleague Dr. Philip has introduced me to eating it with watermelon which is delicious! Thanks Dr. Philip!
- If you like a more intense experience, eating the pulp straight out of the fruit is a gastronomical powerhouse of flavor.
- Bet it would be great on top of a muffin or a scone.
- Passion fruit ice cream sounds great too.
- Uncut fresh fruit should last a few weeks in a cool area of the kitchen without refrigeration.
- Please let me know your favorite passion fruit recipes in the comments section below.
Passion Fruit season:
- Passion fruit ripens about 2-3 months after pollination. In California, this typically means that the passion fruit harvest season is from the late spring to fall.
- The fruit drops to the ground on its own when ripe, which makes it really easy to know when the fruit is ready to harvest. This also makes harvest an “Easter Egg Hunt” like experience.
- In optimal conditions, passion fruit may start to fruit in one year. My growing experience is to get a handful of fruit in the first-second year of plant life and then lots of fruit thereafter.
- This is a climbing vine which sends out long spiral tendrils that can hang on to all sorts of supports.
- The abundant deep green leaves are 3-8 inch long. Therefore, the plant can quickly provide privacy as it grows on a fence. The vine can also quickly cover an arbor/trellis. However, with that fast growth, the vine also requires training to keep in check.
- The plant can get heavy, therefore utilizing a strong support to grow on is important.
- The plant is also relatively short lived (5-7 years). Therefore, plant succession planning is an important consideration.
- Passion flowers are beautiful and add an exotic accent to a landscape.
- I think you can probably prune anytime you need to… and considering the fast growth of this vine, that is probably the most realistic option. Of course, removing dead and diseased plant parts should happen anytime you see it. However, some have advocated that in cool winter climates such as California, you should prune in the early spring. In warm winter climates such as Florida, some advocate to prune after harvest; which I honestly don’t understand because harvest time can be most of the year in Florida.
- Importantly, pruning or moving vines around during fruit development may result in fruit sunburn.
Passion plant growth speed:
- This is a very fast-growing vine that can grow up to 20 feet a year!
- In my experience, these plants tend to go through growth spurts in the spring and early summer. Growth slows down while fruiting and growth basically stops in cooler months.
- I have my plants growing in rich sandy loam (this is basically well-draining rich organic soil mixed in with sandy soil).
- Excellent draining soil is critically important for these plants. Soil that is low in salts is also benificial.
- Check out my article on successful planting/transplantation for some additional helpful planting tips.
- Frequent deep watering is important and will keep your plants flowering for most of the year. This is not a drought tolerant plant and it is unforgiving of bone-dry soil. The plants require more water during fruit maturity and may prematurely drop fruit if water stressed.
- Growing passion fruit vines in containers is definitely possible, however, it may be challenging to keep up with the increased watering demands because the soil in containers tends to dry out fast.
- Passion fruit plants do best in full sun unless you live in an area that is really hot/dry. In hot and dry regions, partial sun is preferred.
- However, I have grown passion fruit vines indoors when I was living in a tiny Boston apartment. The plant did fine indoors and produced flowers although I never got any fruit.
Passion fruit fertilization:
- The intrinsic fast growth of the plant means that it will need more fertilizer.
- Fertilizing frequently is a much better option than hitting them all at once in one shot. Fertilizing 4x a year from early spring to late summer is my general timeline. I prefer not to fertilize in the winter because I don’t want to encourage young sensitive growth in the colder months.
- Some have advocated using a fertilizer with NPK of 10-5-20. However, I personally tend to recklessly and randomly use whatever fertilizer I have on hand and I have more fruit than I know what to do with. Looking forward to getting feedback on this one.
- In general, the purple passion fruit vine is a subtropical plant that does best in a frost-free climate. If they get hit by a frost they will likely loose leaves, and may even die-back to the roots. However, if the soil does not freeze, they may come back from the bottom. Therefore, don’t give up on them if you see massive die-back after a cold snap.
- Some varieties are more frost tolerant than others. This plant also does not grow well in intense dry heat. In general, this plant does well throughout Southern and mid-California up to the San Francisco area. The plants also seem to prefer the moderating effects of coastal regions.
- The yellow variety is more tropical, and is even more sensitive to cold/frost. Therefore, the yellow variety may do better in Florida than in California.
- Making the best use of the geographic orientation and the micro-climates of your yard may help keep to your plants at the optimal temperature range. For example, avoid growing your passion fruit vines in natural depressions in the landscape that can collect heavy-cold air in the winter. Growing on the south side of a building will provide additional reflected warmth and radiant heat; which can be good and bad. Extra warmth is great in the winter but too much heat in the summer can cook your plant.
- Frost cloth protection is another alternative but is challenging or this plant because of the large size of most passion fruit vines. If you use frost cloth, concentrate on covering the core and base of your plant. For more information about frost cloth and preparing for a cold snap, check out my article on the subject here.
Passion fruit flowers:
- Passion fruit flowers are wonderfully exotic, complex, and amazingly beautiful. A striking component of the flower is the numerous thin projections that radiate outward forming a sun-like corona.
- Unfortunately, the flowers tend to only last for one day.
- Below is a time-lapse video of one of my passion fruit flowers opening and closing in one day.
Passion fruit pollination:
- Purple passion fruit is self-fruitful (which means it can set fruit without needing a different plants pollen). In other words, you only need one plant to get fruit. However, the yellow variety is self-sterile (meaning it is sterile to its own pollen and incapable of self-fertilization).
- Apparently carpenter bees are the most efficient pollinator of passion flowers, however, I haven’t seen any visiting the passion flowers in my yard. Honey bees are also able to pollinate passion flowers. Although I have a lot of honey bees buzzing abound in the yard, I have only seen a few demonstrate any interest in the passion flowers. Therefore, because I have so much fruit, I can only guess that the minimal activity of honeybees is enough to do the job.
- Because the pollen is sticky and heavy, wind is not particularly helpful for pollination.
- The flowers can also be hand pollinated. I created a picture of key passion flower anatomy to help anyone interested in hand pollination (see below picture).
- The triple-branched light green structure at the top of the flower is the style. At the tip of each branch of the style is the stigma (see green arrow in the picture below).
- The five banana shaped structures surrounding the mid part of the passion flower are the anthers (yellow arrow).
- To hand pollinate, transfer the pollen from the anthers to the style. You can transfer the pollen with items such as a q-tip, watercolor paintbrush or small piece of cloth.
Passion fruit propagation:
- Plants will readily grow from fresh seeds, and germination should take just under a month. Interestingly, I have noticed that different seeds from the same fruit will germinate at significantly different times. I have seen this with other plants and I believe it is an adaptation to increase the odds of survival (in case something bad happens to the environment during one random week and not another).
- I suggest planting the seeds about 1/2-inch-deep, although others have suggested 1-inch-deep.
- Passion fruit plants can also be propagated by cuttings and grafting. I am looking forward to hear your experiences and insight on vegetative propagation.
Passion fruit pests:
- Nematode infection is a major concern for passion fruit plants (See my article on nematodes here). The purple variety is more prone to nematode infection than the yellow variety. Some yellow varieties of passion fruit are to particularly resistant to nematode infection and therefore have been used as rootstock.
- Fusarium is a family of fungus, and some types can be very harmful to passion fruit plant roots. For example, the disease known as ‘base rot disease of passionfruit’ aka ‘fusarium wilt of passionfruit’ is caused by the organism Fusarium oxysporum f.sp. passiflorae. This infection will make a plant wilt and look like it is not getting enough water. Unfortunately, this infection can cause plant death in as fast as 4-14 days. Fortunately, I believe this is rare in the US.
- There are also other fungal infections that infect passion fruit plants to a lesser degree.
- Disease prevention is always the best option. This starts with buying and promoting the growth of healthy plants through optimal growing conditions.
- Gardening tool sanitation is important for all of your plants and can help prevent the spread of many types of plant disease. Removing dead and diseased plant parts is also very important for overall plant health.
- Snails have been reported to be a big problem in some areas, sometimes being so bad to the point of killing young plants. Fortunately, I have not seen this myself.
- A great advantage of growing passion fruit (at least in my area), is that marauding rodents and birds seem to be oblivious to them. This in part is likely due to the fact that the skin of the fruit is thick and hard to get through without a knife.
- The purple passion fruit variety is native to South America (mainly Southern Brazil, Paraguay, Northern Argentina). The yellow variety is likely native to an overlapping warmer range in South America.