This is the common name but no, it isn’t even related to roses or apples. Its scientific name is Syzygium jambos and it is in the same family as pohutukawa, feijoa, eucalyptus and monkey apples, the Myrtaceae family.
Rose Apples are thought to have originated from south-east Asia and from there have been transported and planted throughout the tropical and subtropical world where they will grow from sea level, (they are very salt tolerant) to higher, even windy, places but they will not fruit where frost occurs.
These trees are evergreen with shiny, green simple leaves and can grow up to 10 metres high. They usually grow much wider than the height. They can grow in shade or sun and over time tend to make stands of trees but as the fruit are heavy they only spread very slowly.
The flowers and fruit are the main attraction of this tree. The flowers are like huge white pohutukawa flowers sometimes with a touch of yellow in them and occur in clusters of up to 5 or 6. Nectar is produced which is appreciated by birds and insects. After pollination the fruit take about 3 to 4 months to form and ripen after which they are eaten usually as a fresh fruit. The seed can be taken out and the centre stuffed then baked or they can be used in preserves and jellies. Because the fruit is very easily bruised and is perishable it is seldom seen in markets throughout the world. The tree is seldom a heavy cropper. Some people find the fruit insipid but I quite enjoy the fruit from my plant though I have never had very many ripe at once. The flavour is like rosewater with reasonable sweetness and a crispish flesh.
Tannin and a brown dye can be extracted from the bark and the timber is good firewood but not very good for anything else.
Guava or Fruit Drilling Moth caterpillars enjoy this fruit so be aware when eating.
As this tree is tolerant of a wide range of conditions, has good flowers and interesting fruit it deserves to be grown more often.