Several thoughts:
1. Lawn maintenance is a taxable service in Texas with one caveat. If you are working by yourself and generate less than $5000 in annual revenue you do not have to collect and remit sales taxes. If you have a crew or you're over $5000 you must collect and remit sales tax.
Comptroller Website on Lawn Care Services. Please pay attention to this. A lot of people assume this is not taxable because it is a service but that is incorrect. The Comptroller is extremely unforgiving and would rather close you down than not get their pound of flesh.
2. The barriers to entry are low. What does that mean? It means that if you hire a crew, teach them what and how and turn them loose there's not a lot to stand between them and going out on their own. A truck which they already have, a trailer, push mower and a weed eater. That's it and it's not much. This isn't meant to dissuade just to make sure you realize you'll have to be consistently hiring.
3. Like someone else said mowing isn't a money maker. It churns a lot of cash and gets your name out there for more profitable landscaping work but there's not a lot of money in $40/yard mowing. What profit can be squeezed from it comes from efficiency. My mowing company does about six houses a trip of lawns that are all 2-5 acres. We pay $80/trip so do the math and that's good revenue for three guys in one day with no driving between jobs.
That's all I got for now. If I think of more I'll revisit this. Good luck!