catoniaster

[tallyot]

how do i stop a catoniaster growing any higher and when is the best time to do it.

[madmaggot]

You won't stop it growing, you will just have to prune it. You don't have to do anything special just cut off the bits that are growing where you don't want them.
Try not to cut it too much though, the bees love it.

[ailie]

There are different varieties, some are prostrate & won't grow high..... in my experience, it's rampant & seeds really easily, you might not win if you take it on!