The water apple or Syzygium aqueum is not actually an apple. The water apple's fruit is cone shaped and only 3/4 of an inch long. Its name is closely related to its flavor, which connosieurs often refer to as "watery" or "tasteless." But, like water, the water apple tree's fruit is thirst-quenching and often eaten raw. Native to southeast Asia, the water apple is a tropical plant that is most often grown in southeast Asia, Hawaii and Trinidad. It is easily propagated from seed, however, and can be encouraged to take root indoors. Later transplantation out of doors after two years should only be considered in tropical areas of the United States with high levels of rainfall and followed by a dry season.
Obtain fresh seeds. Water apple seeds quickly lose their viability. They should be planted immediately after they are harvested from the fruit.
Fill a small pot with quality potting soil and gently pat the soil down with your hand.
Plant the water apple seed 1/2 inch deep.
Water the soil until water runs out of the bottom of the pot. Continue to keep the soil moist until the water apple seed germinates. During its first two years of growth, your water apple's primary need will be adequate water.
Move the pot to a sunny, indoor spot near a window.