The Ponkan Mandarin is self fertile, as are almost all mandarins. Ponkan is a great tree to grow, and produces fruit larger than most mandarins, plus the fruit has a pleasant sweetness to it. I take it your question about how fast it bears fruit, is asking the length of time from seed to bloom. Like most all mandarins maturity from seed is approximately 3 to 5 years when grow in an area such as Florida or California.