To answer the topic question, no. IME, no matter how healthy or thick your lawn is, if you have voles, they have the potential to destroy it with their tunneling. And wreak havoc on the rest of the garden as well.

But weed control and fertilizing does encourage a healthier, denser lawn and that will certainly be more resistant to drought and bare patches.

Thanks gardengal. Makes sense. Im currently on a 5-step feeding/weeding program that costs $1k. I'm thinking of just going with organic feed and doing it myself once in spring and once in fall. I like the way the odd clover looks in the lawn.

I don't live where a pristine lawn is a requirement - no HOA's controlling the neighborhood - and I am not at all regimented about lawn care either. I am perfectly happy to let my lawn go au naturel :-) While there is is plenty of turf grass, there are also plenty of weeds. I manually remove the biggest offenders - dandelions and the like, rumex, etc. But I will allow the smaller creeping ones like clover, veronica, lawn daisies, even creeping Charlie and some ajuga do their thing. It just helps to keep things green virtually all year and the seasonal flowers some produce just add to the appeal.

I live pretty far north and cool season turf grass blends are the norm here. This is also a recurring summer drought area - we are typically bone dry July through September and often into October. When I lived in Seattle, we had a tiered water usage fee system and unless one had the financial wherewithal to pay outrageously high water bills, many opted to just let their lawns go dormant in summer as cool season lawns want to do by watering only enough to keep the turf alive. It would spring back to healthy green growth as soon as fall rains arrived.

So obviously, summer fertilization was not advised. Why encourage a lawn to grow during the period of time when it does not want to grow and would require copious watering to maintain? Frequent fertilization here is not encouraged for various reasons and most local sources recommend on a twice yearly application at most - mid spring and mid fall. Much like you plan to do :-)

While you no doubt will get some differing opinions and there will of course be regional variations, what you propose is certainly doable. It just depends on what you expect from your lawn.

" Makes sense. Im currently on a 5-step feeding/weeding program that costs $1k. I'm thinking of just going with organic feed and doing it myself once in spring and once in fall. "

You can definitely get off the five-step. I've never seen a more overpriced, ineffective system in my life. I feed five times a year myself, but total cost on a very large lawn is less than $200, and that's overkill done organically.

To determine what would be best, and if a twice yearly would look good and work for your lawn (some yes, some no), we'd need to know what kind of grass you have and what your nearest city you live. It'll probably work, but some grasses in some locales will seriously look like serious crap doing that.