This guide does not answer the one burning question that I have when playing most Druids:

How do I use my action & bonus action when I'm concentrating on summons? At level 9, I can use my action to... maybe hit for 2d6 damage within 30ft, optionally pulling a guy out of cover while doing so? Hitting for 2d8 often-resisted damage at 30ft isn't much better. And by now, Erupting Earth hasn't picked up on damage yet.

Plant Growth, Transmute Rock, and Bones of the Earth are absolutely great, yes, but they're situational, and if you pre-bake the battlefield with them, then you come back to the original problem. Best I've got so far is "turn into a horse for more party mobility", but if you've already got a horse... then what?