I'm sure we could do better with an addon that shows how much juice they've sucked up though
From: http://elitistjerks.com/f73/t130799-resto_mists_pandaria_5_2_a/p31/, a Weak Auras string.
"I made a WeakAuras display to do that, if it's of any interest to you. Just quoting my post from another forum:
I just threw this together for my own use and figured some of you might find it useful as well. It's a Weakauras tracker that shows (as a number) how much healing is stored in your mushrooms, along with a bar that fills up based on the total capacity (which depends on max health and number of mushrooms).
Weakauras import string: dKueFaGiKuxcbv1OaqNcawfQkEfkrMfOOBrQyxOQ6xKkPmmeYXqILrrEgk10OOQRHQsBdjPVHGkJdkIo - Pastebin.com
Note that I wasn't able to figure out a way to track the buff on the mushrooms themselves (since it failed to trigger COMBAT_LOG_EVENT_UNFILTERED or UNIT_AURA), so I'm actually just tracking the rejuvenation overheal itself and summing the amount done while each mushroom was active. This means two things.
If Blizzard rebalances mushrooms, this tracker will have to be adjusted for the new figures (i.e. I've incorporated the behavior "25% of overhealing up to 33% of player max health" into the tracker).
There is the possibility that this tracker could produce inaccurate results in some edge cases. However, I've tested every realistic edge case I could think of and the worst discrepancy I've been able to produce is of order 1 rejuvenation tick (owing to a small time offset between when I start counting overheal toward a newly-spawned mushroom's growth and when Blizzard does).
Also, it would be trivial to show a separate tracker for each mushroom but I figured that would just be extraneous.
Probably not the best possible implementation, but it's worked well enough for me on PTR."
And an Addon: