http://www.crfg.org/pubs/ff/loquat.html

Here is a link that might be useful: CRFG Loquats

They start showing up in December and continue through early January. Harvest in April-May. Big Jim generally takes 3 to 4 years in the ground before it starts producing.

Unfortunately the flowers are frost tender.

my Big Jim loquat is 7 years old and about 10 feet high. The leaves are very strong and healthy appearing. The tree has never blossomed or fruited. I was told this variety is self pollenating. I live about 7 miles inland on the Calif. central coast.
Any suggestions?