Age & Size of a Pomegranate Tree
It is impossible to know the exact age of a pomegranate bush or tree growing in a nursery pot or container of any specific size. This would depend on how long the plant has been growing in the pot; whether it is a "new crop" or an "older crop." That said, below is the approximate age of pomegranate growing in various size nursery pots.
1 Gallon Pot - 12 to 18 months old (approx plant size: 12 to 18 inches tall)
2 Gallon Pot - 24 to 30 months old (approx plant size: 18 to 24 inches tall)
3 Gallon Pot - 36 to 48 months old (approx plant size: 24 to 36 inches tall)
At what age will a Pomegranate plant begin to produce fruit?
When a pomegranate tree will begin producing fruit after planting time will depend on environmental factors such as climate, sun exposure, soil, etc, and other variables such as the age of the plant obtained and care practices.
In general, though a pomegranate tree might flower at an earlier age or produce small fruits, if growing in a site where happy it won't begin to produce large fruits until at least its 4th year of age. So, if you plant a 3 year old tree it might take only one year after planting to begin producing fruit. That said, rarely will a newly planted pomegranate tree of any age or size produce fruit during the first year after planting, when the plant will use its available energy to establish roots in its new home (your garden) rather than to produce fruit.