THE 2-MINUTE RULE FOR SAN PEDRO CACTUS FOR SALE NEAR ME

I’ve been growing San Pedros for many 40 decades. They’re in the sunny bay window and they develop high-quality, Nevertheless they under no circumstances branch (except where I’ve had to trim them), plus they’ve in no way flowered. How can I get them to flower?Quick question, I have a few seven inch extensive, five inch large slicing of SP