Pre-soak seed for 24 to 48 hours in a glass of lukewarm water. After they have been soaked check to see which seeds are floating and which ones have sank to the bottom of the water. Any that are floating can either be thrown away or left for a further 6 hours.
Passiflora Seeds should be sown about 2 to 5 cm deep in beds or pots. Soil should be kept moist and not allowed to dry out. This can be best achieved by placing your container in a saucer of water and sealing the lot in an inflated plastic bag and placing it in a warm sunny position although a seed propagator or seed tray placed on a heat mat under light is more suitable as can be controlled easier.
Bottom heat temperature should ideally be in the mid 20's (ideally at 20 degrees C for 16 hours and 30 degrees C for 8 hours each day) this will stimulate germination rapidly.
Seedlings will grow quickly and should be transplanted when they are around 25 cm or larger if weather and environment is not optimum.
Site in a well watered, hot, sunny location and fertilize regularly. Passion fruit vines grow on many soil types but well-drained light to heavy sandy loams with a pH of 6.5 to 7.5 are the most suitable although it does not have to be this specific to achieve nice healthy growth.
Growing media best suited is a mix of half loam based mix with a quarter peat and a quarter of sharp sand to improve drainage. Alternatively and one we have used extensively is half perlite and half cactus compost mix which is almost always reliable for any plants requiring a quick draining potting mix. Whatever soil type you use the most important factor is for the soil to be very free draining.
This also applies when planting in the ground as it will help plants establish much more quickly. Very small plants will do well just in a peat mix which is easier for the young roots to penetrate. The soil should be rich in organic matter and low in salts. If the soil is too acid, lime must be applied. Because the vines are shallow-rooted, they will benefit from a thick layer of organic mulch.
As passion fruit flowers on new growth, they may be pruned early in the growing season. Pruning is necessary to keep the vines within bounds, to make harvest easier and to keep the plants productive by maintaining vigorous growth. It is best to cut some stems back nearly to the base in spring.
Your vines can be trained very easily around structures of your choosing even indoors!