The capitalization of an industrial plant won't be the same for a car dealership or retail, an agricultural business is much different than just accessing raw land or residential lots.

Can you make some specific suggestions for plants that are low maintenance, not to costly to install and/or other ideas such as mulch/gravel/hardscaping in lieu of plants?

I've always been interested in real estate, but we have been living abroad for 11years - we have bought a few properties that we have either sold or held as rentals from afar, but now that we are finally getting planted in one place I am looking to invest locally.Are the rules strict on rentals?  

I am sure you are not looking into investing into a food plant but we install very large refrigeration systems that need maintenance.

I redid the guest bathroom, updated light fixtures throughout the house, repainted the whole interior, updated appliances, built furniture, added a garden space and a variety of fruiting plants, and so much more I can't even remember.

Caterpillar is in deep judicial stuff on top of their plant closing and layoff announcements.

Or open a steel manufacturing plant if you had enough money?

The state's 3rd largest university is located here as is a large nuclear plant that regularly brings in MTR-type tenants for outages. 

To your point though, maybe planting some shrubs along the back property line would help.

@Jeffrey Kingman, you're wife's dad is on the right track and in fact, we're starting to see this now in Georgia with Hyundai's new construction EV power plant link.