Thanks for your reply rdback. I'm in southern California, and actually reached the same conclusion as you, and ordered some of those mole/vole castor oil repellent pellets. They should be here soon. Let's hope they work, because my plants in that raised bed where the voles are apparently at work are rapidly disappearing!

I think it is far more likely to be a gopher. They're very common in SoCal and they are large enough to actually consume an entire plant. Voles are tiny little things and unable to remove or eat an entire plant that is easily 5-10 times their size. And moles don't eat plants at all.

An way to tell is that voles (about the size of mice) leave small tunnels and gophers (about the size of a squirrel) digs much bigger ones and often leaves evidence on the surface.

Do you have Harvester ants? We do and they stripped my spinach, lettuce, rosemary, onion tops and even the okra! They’re currently working on the poinsettia‘s that come up like weeds in the flower beds so I’m hoping that keeps you them busy for awhile.

fascinating about the harvester ants - had to read more about them; we have tons of ants here, but so far as I know they're just the standard kind.

I was able to narrow it down to voles because I found small tunnels with no dirt above ground. Also they prefer to target my root vegetables. they have been eating entire diakon radishes. they seem to gnaw at the roots gradually underground, until eventually the entire radish is demolished.

I got the castor oil pellets and have done several applications - but they appear to be completely useless. the voles are still active. I also tried to dismantle some of their tunnels and refill them with soil - but I'm not sure if they will have any effect.

It's hard to know how to handle them. I was hoping to deter them and don't want to go so far as to kill them, so for the time being I'm just doing any my planting in containers.

Good thinking on growing your veggies in pots until you figure out a way forward. We have pocket gophers along with the harvester ants. The next thing I’m trying in the garden is Hugelkultur raised beds. I’ve put dead pine tree branches and hardwood logs in long rows. Topped them with homemade compost and dry grass clippings, cardboard pieces and more compost. I left plenty of room between each row to walk easily. I’m hoping the gophers and moles won’t be able to come up through all of the logs etc.... for awhile anyway! Will plant all of my root vegetables in those raised beds and will mix in a Variety of herbs to see what happens. Should be an interesting experiment!