Pine Needle Mulch

Pine Needle Mulch

Im in zone 6, Colorado with a fully xeriscaped lawn. My summer project is rebuilding my beds as the latest doggy addition to my household has taken to digging in them. Once I build up some walls and add some much needed soil, I will need to mulch the beds. Would pine needle mulch work in my case? I like the look of it but am afraid of the acidity.
Plant ID and possible fungus ID

Plant ID and possible fungus ID

Gourds and tomatoes

Gourds and tomatoes

A hardy caladium

A hardy caladium

Update to my garden…

Update to my garden…

Succulent ID

Succulent ID

I need photo arrangement help! Plus photos of part of my apartment!

I need photo arrangement help! Plus photos of part of my apartment!