Looking at your most recent logs, your druid used Nourish 518 times over about 17 fights on Tuesday. That number should be close to zero. The ONLY reason to use Nourish right now is to extend Lifebloom if the tank isn't 100% topped off, but also is taking very light damage and has no chance to take damage spikes, plus the entire raid is 100% topped off. So bascially never. Glyphed Regrowth is a faster cast skill and does more more heals per mana than Nourish. This isn't Cata- he needs to take nourish off his bar. His Regrowth + Living Seed averaged about 105k heals per cast, while Nourish averaged about 36k per cast- Regrowth mana cost > 3x Nourish mana cost, so using nourish period is a HPS, HPM, and net mana loss.
To sum up: In order to get 105k healing out of Nourish, it costs 30.6% base mana and 7.5s of casting (before haste). To get 105k healing out of Regrowth, it costs 29.7% base mana and 1.5s of casting (before haste).
He also didn't use Wild Mushrooms a single time. It's already incredibly powerful for what it does,  in a couple weeks in 5.3, it's getting a range increase and a 100% buff [/edit], with Rejuv on the raid during heavy periods of damage, this can sometimes give out (smart) pulses of healing as powerful as Revival with a 12 second cool down. With the dozens of GCDs he'll free up by taking Nourish off his bar, he'll be able to place mushrooms strategically and have some burst AOE heals available when needed. Wild Growth use is pretty low too, I personally almost never glyph it, but my druid is also MS Guardian, so most of my healing is done outside of raiding. Resto Druids are performing better than Holy Priests and Resto Shamans in both normal and heroic 10m these days. Weaving in Cenarion Ward (massive buff in 5.2) on some fights with very regular, predictable damage can also be a helpful tool-like Tortos stomps, Dark Animus' Interrupting Jolts, and Ji Kun's pool soaking and Quills.