To grow passion fruit, several factors must be taken into consideration, including climate and site selection, soil amendments and proper planting as well as adequate watering, fertilizing, and annual pruning. Most passion fruit varieties need an environment with light to no frosts, along with wind protection and acidic, well-drained soil. Amendments and the addition of organic matter may be necessary, as is light root trimming before planting above the soil line. These vines need constant moisture and frequent watering, especially during fruit maturation, and a yearly pruning of dead and some new growth ensures prolific blooming in the following season.
Depending on the variety, passion fruit is either a tropical or subtropical plant, sometime withstanding extremely light frost at about 20° F (about 7° C). Planting in a proper climate is essential for passion fruit to thrive. The vines also need adequate rainfall, about 35 inches (88.9 cm), otherwise they must be grown in an indoor container. Choose an area with wind protection and well-drained soil that is slightly acidic. The vine does well in full sun and will tolerate partial shade.
To grow passion fruit, soil must be tested or amended to a pH between 6.5 and 7.5, and organic matter should be added before planting. Compost works well, and these shallow-growing roots typically need a thick layer of mulch for protection and moisture retention. Preparation should take place one month before planting.
Passion fruit is usually sold as a seedling. Roots should be pruned on a cool, cloudy day about two weeks before transplanting. When placed in the soil, roots should be gently spread out. If the seedling has a grafted node, the joint should sit above the soil line for protection from pests and disease. If planting more than one vine, setting them at 10 feet (3 meters) apart can yield higher fruiting, and planting near a tall tree or trellis increases chances of blooming and help grow passion fruit.
Proper irrigation is required to grow passion fruit. Watering every few days keeps the vine flowering continuously, and letting soil dry may make the blossoms fall prematurely. Watering frequency should increase at the end of the fruit's maturation stage, as it ripens quickly at this point.
Fertilizing your passion fruit vine ensures vigorous growth and prolific blossoming. Applying 3 pounds (1.36 kg) of a 10-5-20 NPK plant food four times each year typically works well. If you notice less flowering and vigorous foliage growth, fertilizing may need to be cut back. As you grow passion fruit, pruning can keep an established plant healthy and is best done in early spring. Removing all dead or weak growth and trimming back about one third of vigorous growth keeps the passion fruit blossoming and fruiting.