Meh, I have to disagree with the the suggestion to use the Regrowth glyph, for PvE at least.
Baseline, Regrowth has a 60% chance to crit. Add another 5% crit from raid buff and maybe 5-10% crit from int/gear and you are looking at around 70-75% chance to crit before using the glyph. While the hot component is weak it is another source for Swiftmends. Omen of Clarity Regrowth followed by swiftmend is a lot of healing for not much mana
For PvE, I personally don't see a glyph that adds at best 30% chance to crit (to a spell already very likely to crit anyway) as worth losing the extra small amount of healing from the hot and more importantly more swiftmend opportunities.
The gylph also will get worse and worse as our int/crit increases from gear upgrades (im not even 450 ilvl - no gems or enchants except LW bracer 500 int - and i have 10% crit, giving me 75% chance for RG crit in a group/raid)