Bassandgrass -- even in the north country, bass maturity is still more a function of size than age. Largemouth bass males should be close to 100% maturity by perhaps 11 inches, and females by perhaps 12 inches. Some will spawn perhaps an inch or so smaller than that.
Age does factor in a little. If you have a 1 year old, 10 inch male LMB, it may not be mature that spring. If you have a 5 year old, 10 inch male LMB, it may very well be mature in the spring.
