Although I’ve recently replaced this with the Spark of Hope, I thought I’d share this macro I used with my Spirit-World Glass.

#showtooltip Wild Growth
/use Spirit-World Glass
/stopcasting
/cast  [target=Angela] Wild Growth
/script UIErrorsFrame:Clear() 

Basically this targets me, and casts Wild Growth.  If my Spirit World Glass CD is up, it casts that, if not, we have that little no-error line in there so you don’t get spammed!  You can change the spell and the target to whatever you want, but make it a spell you cast often.  This way you’ll be actually utilizing the trinket.  

As far as the wild growth is concerned, I have this macro repeated three times.  I have one set for me, one set for the tank/melee, and one set to a ranged person I know won’t die  It makes AOE healing a lot quicker.