Additional photos

Looks like you have a lot of space and several large healthy shrubs as well as palm trees and what could be a jacaranda.

Is your budget mostly elbow grease for pruning? If so, I'd prune the dead palm fronds, rake the ground, and sweep the sidewalks. Then take photos out your windows that look at the side yard. Decide what you want to see. If you are not going to water the area, use large pebbles or shredded bark as a ground cover. If you are going to water it, you can put in some new perennials, then fill with shredded bark.

You can volunteer to paint the mailboxes. Not a big deal.

You might consider moving the baseball sized rocks to the base of the mailboxes. Then fill the rest of the ground with shredded bark. The low wall might look better after being blasted with a hose or it might need painting.

I am confused. Is your shared mailbox on your property?

can we see more photos of the style of your home. hard to recommend when it's not entirely visible. if that were my side yard I'd put up a slatted modern fence to block the view to the neighbors home, then clean up the shrubs and lay down rocks with low maintenance plants like succulents

If that truck is ruining your view a wood fence could be a simple solve.

A fence might work well, I agree. Check local code for height restrictions first.

Thank you apple_pie_order, those are pretty simple and inexpensive fixes.

I'd love to remove the tree. It makes a huge mess.

Yes Margo, their mailbox is on our property. I guess it was a decision made between the previous owners of both homes way back in the day.

Jacarandas are pretty when they bloom. But they often break in high winds. They do add to property value when nicely maintained. Trees block sound, too.

You can also add geraniums near the mailbox. It all depends on what you want to see when you look around. Rocks are simple.

In photo #3 is that large tree stump in your yard or the neighbor's yard? If it is in your yard, it would be good to get it out or grind the stump at least. Stumps in yards promote termites over the long term and contribute to the 'messy' feeling of the yard.

Is that small block/stucco wall the dividing line between you or is that a decorative element on your property?

I really like the idea above by JWoody of a fence between you and your neighbor. Something like this one where you can put appropriate landscaping on your side for easy maintenance.

Or something like this one especially if you can go to a higher level to block out the neighbors yard

Celestine- unless that mailbox has been grandfathered in, it would not take me long to relocate it'))

Here is a favorite fence treatment of mine that might look fantastic between you and your neighbor. It is vertical landscaping - a mix of fence and plants

Your side yard looks sloped Can you use a ground cover plant there, it will help with erosion and add life to the area. I would as a good neighbor offer to repaint the post and get a new mailbox and offer to pick one up for them as well, with them paying, of course.try to keep the tree as it gives you some privacy.
Might turn what sounds like an unfriendly situation into a good one. I hope so.

Hello and happy Saturday everyone. Thank you for all of the comments - last weekend we purchased two new mailboxes, one for the neighbor and relocated theirs for them:) (with their permission of course.

Also, we've decided to have the tree removed. It's making a mess not to mention killing the neighbors grass.

I'm going to clean up the entire area; re-pattern the rocks around the mailbox in a pretty design. We've also decided on a natural fence between the two properties using posts, wire, and a few nice vines to fill it it. I'll post a photo!

Thank you for all of the great ideas!