Neighbors Bamboo Spreading 20+ Feet Into Our Yard - Any Options? (location: Southern California)

Location: Orange County, California, USA

Looking for some advice from anyone in Orange County, CA (or CA generally) who has dealt with invasive bamboo coming from a neighboring property, particularly if you have experience with the legal/property side of it.

Our neighbor has a large amount of bamboo planted along our shared backyard fence. The bamboo has spread underneath the fence and the underground rhizomes have now traveled roughly 25 feet into our property - they are popping up all over our backyard grass and planters.

We’ve been talking with our neighbors about this for about six months and have been trying to work out a solution amicably. I pitched the idea of installing a barrier underground, and splitting the cost, back in April when we first noticed the issue, but they've been non-commmunicative and dragging their feet since then and the problem has gotten much, much worse. They have finally said they will split the barrier cost, but we're now looking at an additional $3000-$5000 of landscaping bills to rip out that portion of our yard, try to kill the bamboo, and re-plant grass in that area.

For context, the barrier install will be $3300-$4000.

I've been amicable throughout the process, we've talked on the phone, via text, and in person.

I am feeling a little screwed in all of this - so I am wondering what, if any, options we have here.

Specifically, I’m curious about:

• Under California law, is a homeowner generally responsible when bamboo planted on their property spreads underground and damages/encroaches on a neighboring property?
• Can the affected homeowner require the neighbor to remove or contain the source of the bamboo, or is my only option to remove whatever crosses onto my property?
• Can remediation/property repair costs potentially be recovered from the neighbor?
• Would this generally be handled as a private nuisance/property damage issue, or is there anything code enforcement would get involved with?
• Is there a particular type of attorney I should speak with if we can't resolve it ourselves?
• Is there anything I should be doing now to document the situation before we start excavating/removing the bamboo? I have been taking photos and measurements throughout the process.

I have plenty of photos documenting the spread and measurements showing how far it has traveled into our yard, as well as the any text conversations with our neighbors.

TLDR

Not looking to immediately sue anyone. I'm mainly trying to understand what rights/options we have and how other people have handled bamboo encroachment from a neighbor's yard before we potentially spend thousands of dollars fixing a problem originating from the neighboring property.

Thanks for any advice.