Hi there, sorry if this is a typically annoying post but I'm having a really annoying time trying to get my hibiscus growing.
I decided to line my paths with 'walls' of bushes, which worked perfectly on one side, but not the other for a reason I can't think of.
I know that bushes can only be planted next to other bushes or trees, and that the connected line should be no longer than 12 bushes long, which mine does not exceed.
I've took a photo to show what the issue is:

Sorry for the low quality. The gaps between the yellow bushes are where my two red ones keep mysteriously dying.
Any advice would be fantasic.
I decided to line my paths with 'walls' of bushes, which worked perfectly on one side, but not the other for a reason I can't think of.
I know that bushes can only be planted next to other bushes or trees, and that the connected line should be no longer than 12 bushes long, which mine does not exceed.
I've took a photo to show what the issue is:

Sorry for the low quality. The gaps between the yellow bushes are where my two red ones keep mysteriously dying.
Any advice would be fantasic.