Fertilizing Passion Fruit
My husband and I went to your presentation at Del Mar, you taught us a lot of information, Thanks! We have 2 frederic passion vine, that are suppose to fruit, 2 years old we got flowers but zero fruit. We have one red that has never even flowered but has spread. The 1st year used Dr Earth flower fertilizer. The 2nd year used organic fruit fertilizer. What type & brand do you recommend for organic fertiziler for this plant since it has not fruited?
Answer from Pat:
Your passion fruit vines (Passiflora edulis’Frederick’ and P. edulis ‘Red Rover’ or ‘Red Ambrosia’) are sweet, good-tasting varieties of fruiting passion fruit vines, but they are tropical vines most successful in a warmer climate than coastal San Diego may provide. The easiest variety to grow here in San Diego County is the purple-fruited one. Usually passion fruit begins to bear fruit after a year or two, but we have had some strange temperature swings and cold nights. Too much chilly weather when the vine is young might slow down the beginning of bearing. So I would not yet give up hope of success.
Passion fruit vines prefer full sun along the coast, or a little light shade in interior zones. They want deep, well drained, fertile soil and a warm protected location,such as against a south facing reflective wall away from wind. They bear best when the ground is kept dry during the coldest portion of the year, which has not been the case this year. If given adequate food and water, they grow fast to large size—often as high as 30 feet—and respond well to nitrogen fertilizer. They can get crown rot if subjected to soggy soil or planted too deep and if well grown can adapt to dry conditions better than wet ones. They respond best to deep and infrequent watering instead of shallow and frequent watering. If a passion fruit vine becomes too tall one can control its size by cutting it back in early spring after it resumes growth.
If you read over the requirements above and you see that you haven’t fulfilled some, then I would take that as an indication of what might be the matter. I have several guesses as to what your problem might be: First perhaps the vines are in ocean wind where there is not enough heat. Second: if they are growing in wet soil in winter perhaps combined with poor drainage that could prevent flowering. And third, most importantly: No bees mean no fruit.
I think one of your main problems is failure to understand that passion fruit vines are gluttonous feeders and high bloom ingredients—phosphorus and potassium— are not enough. These plants love fertilizer and this mainly means nitrogen. It’s a great idea to begin feeding at planting time and plant them on top of a dead fish or several handfuls of fish entrails and skin or a bunch of dead fish heads to give them a big feeding boost at the beginning of life. Yes, I mean throw a whole dead fish in the bottom of the planting hole, then add a bit of top soil and stick the plant on top of that and fill in the ground. That plant will take off like gangbusters. (Get spoiled fish, skin, bones, or fish entrails free from fish markets.) I would also mulch the top of the ground over the roots with well-rotted horse manure. If you apply manure next fall before the rains then you don’t even need to age the manure. You can just put it on top of the ground ahead of the rains and let the rains was the nitrogen into the ground. Just keep it 6-inches or 8-inches away from the crown of the plant so it won’t get crown rot.
Passion fruit vines do not require a pollinator, but they do require pollination by bees so the fact that you had flowers and no fruit says to me your problem was lack of bees. (See my video on this topic under videos.) If you have no bees that would explain why you had flowers but no fruit. Next time you see flowers make sure there are bees. If no bees you should hand pollinate.
To hand pollinate passion flowers look inside the flower. The sticky bump in the middle of the flower is the stigma in the middle. This is the female part of the flower and the anthers around it are the male which bear the pollen. In the late morning or early afternoon when the pollen is dry take a small sable brush and twirl it to pick up pollen from the anthers and then dab the pollen onto the stigmas of other flowers. Do this when the pollen is fresh and bright yellow and continue every day or two as long as you see flowers. You need to play bee and do what bees do. They go from flower to flower and from plant to plant they just don’t pollinate one flower and fly away, they do them all. This mixes the pollen and produces good pollination. Another way is to clip off the anthers with pollen intact with a pair of clippers that grab such as flower shears, drop all the anthers from several flowers into a small container and mix it around with your brush then go dab this mix on the central sticky stigma you will see sticking up in the center of each flower. If you have left over pollen you can cover tightly and store it in the refrigerator over night and use the next day.