The best time to plant a tree was twenty years ago.

I would plant some appropriate trees at the back of the property and do a french drain 

They're noise nazis or plants on the balcony nazis or anti-rental nazis.I owned one for about 3 years and made a profit, but couldn't WAIT to get out from under the HOA, and yes, I even got on the board to try and add some experience/sanity to it, but it was a losing, insane battle. 

So you inherited a tenant that sounds like they were never really qualified in the first place to rent the unit for the amount of their lease and in the end getting rid of them is costing you $200 and a tree you didn't pay to plant in the first place? 

It would be one thing if we had a $1,000 flower garden underneath the wall, or some exorbitant risk exposure (i.e. falling into the kids sandbox while kids play) but neither looks to be the case here.If he's concerned about cosmetics tell him to plant some pretty flowers ;) In terms of contractors though, you can call someone who does foundations, or a landscape contractor who does retaining walls.

An electrical surge once in 2014 caused major damage at a previous employer's manufacturing plant when a single plugged in phone in the shop caused a fire.

The real estate agent who I worked with to buy an owner-contract condo many moons ago, always sent her previous clients a poinsettia plant and a nice card. 

She gave me a poinsettia plant and a Christmas card every year and then one day I decided to sell and she got the listing. 

I just read about the Shell Cracker Plant. 

Had the place furnished like a posh pent house, lots of plants in front of the unit made the whole building look nicer.