In preparing soil for planting a vegetable garden, it's a good idea to first rid the area of weeds. Then dig or till the soil to a depth of at least 8 inches. In the process of digging, you can add organic matter, such as compost, to help improve the soil texture.
Banana passionfruit can take a long time to germinate, but soaking overnight in lukewarm water can help speed the process. Keep the germination medium moist and warm (70 degrees F). For more on growing the banana passionfruit, consult the Purdue University Extension guide at http://www.hort.purdue.edu/newcrop/morton/banana_passion_fruit.html.