Growing mushrooms causing server lag

[sirdenero]

I've noticed since someone on my server has started growing these the CPU usage hits and stays 100% but when the chunks unload the CPU runs around 30%.
The console is spammed with this.
[shadesofnether/]: attempting to grow stem east
Doesn't always say east but it will send this message 5-8 times in a second, then I get
[shadesofnether/]: No room in chosen growth direction, putting back the shrooms.
And this message also get sent 5-8 times in a second.

[pyrosshade]

Tracked down the console log lines, those have been removed. Hopefully the console spam was the only thing maxing out cpu usage.