Help! Creating a hedge from scratch....

Hi there

We would like to put some hedging up on our south facing garden in order to have privacy. I can't change the fence itself. I've attached a pic showing the current state of play, which is that we have two planters on the patio (one with new golden bamboo in it).

The golden bamboo isn't screening as much as I would like it to, so not sure what to put in the other planter, or whether to replace the golden bamboo with something more effective.

Any suggestions on the best way to achieve this would be wonderful! Ideally need a solution for this summer - don't want to wait years for something to grow!

Thanks