I'm sure the type raspberries you're growing plays into it somewhat but I get new growth that sprouts from the ground each spring which are that years primocanes. They begin flowering after the second year canes (floricanes) are done producing which is mid to late July for me. The primocanes grow very tall for me and produce raspberries at the top in late summer and early fall. When they are done in late fall I cut the tops off and they become my floricanes for next year.

So do you have new canes coming in that sprouted this year? Here is my post on raspberries so you can see what my hedge looked like in the spring. The one cane poking out of my row cover is a primocane so you can see how high they get.

https://steemit.com/gardening/@garden-to-eat/the-other-red-berry