I don't fertilize much when blueberries are fruiting. But there's nothing wrong or right about that. My criteria is to fertilize when I want more vegetative growth. Since you are zone 9 you will, like me, have plenty of time after fruiting to get new growth.

This is my usual pattern this time of year, harvest, prune as needed, and fertilize for new growth. But sometimes the plant makes plenty of new growth with the spring flush. Then I only fertilize about once a month all summer. If forcing new growth it's nitrogen once a week. This is all in pots and using 21-0-0, ammonium sulfate at one tablespoon per 3 gal water.

fruitnut, with this fertilizing regiment rapid growth is an understatement. Thanks for sharing it.