Weed-B-Gone spray; kills weeds, not the grass. Use it down each side of the property line to keep neighbors weeds from encroaching.

I use cheap weed and feed liquid from Lowes. Yard looks great. Yep use it now.

I would never use a weed and feed. The stuff is dangerous. Here is a small part of an article about Weed n' Feed.

These chemical ‘Weed and Feed’ poisons are directly linked to causing cancer in dogs, cats, kids and adults. And they are harmful to the very plants they are supposed to protect. Pretty crazy. The bags will say ‘Do not apply around trees and shrubs’. Does anybody think that their tree and shrub roots don’t grow in the turfgrass areas? And read the back of the bags. There you find will an EPA pesticide tag plus instructions on how to clean your spreader in a containment box and take the waste water to a toxic waste disposal site. Like anybody is going to really do this. So after we apply these ‘Weeds and Feeds’ we have now poisoned our entire lawn where our kids and pets play and track these poison into our homes.

The best way to prevent weeds is with strong, healthy grass. Spot spray the weeds you have and feed your lawn regularly.

You are absolutely and completely right. I don't like rock yards either. And we did put pebbles down in our planting beds and even with the underlying material weeds will grow again. We trim our own bushes, well actually Henry does 99 percent of it, and afterward blows all the leaves and debris out and rakes it up and puts it in those big leaf bags, but even so, enough leaves fall into the rocks and biodegrade enough to soon have a place for a wayward seed to grow and they do grow, even in the rock beds.

and the lawns here could grow through a steel wall, I am beginning to believe.

Anyway, you cannot stint on water and fertilizer if you want a lawn that is not weedy. It is simple.