I'm very interested in replacing my lawn with a low maintenance, durable ground cover (I love the look of thyme, but I'm worried it might be too expensive). When I look at lawn alternatives, it seems that most people use them in small spaces in a well-landscaped yard. But my yard has almost no landscaping-- just a huge lawn (about 1/4 acre) and a few trees. Are there any ground covers that can quickly cover that much space? I am hoping to find a ground cover that wont be too expensive, and can handle foot traffic.

I would just cover it in stone pavers. It will be easier to keep it clean.

I live in the same zone as you, Bay Area, Zone 9, Sunset Zone 15 or 16, I am never quite sure which, but it’s a colder zone. i recommend considering a Zoysia grass lawn. I have had one for more than 30 years and it’s a wonderful lawn and in my personal experience more drought tolerant than the oft recommended buffalo grass. I grew the UC Verde Buffalo grass in a small area of my garden and after three years I killed it off. I did not like much about it, especially in comparison to my Zoysia lawn. It did not have a good green color, was more gray green than green. It went dormant at least a month earlier than Zoysia and greened up at least a month later. At least! And it was invasive with above ground runners that required constant vigilance to keep those runners from escaping into adjacent planted areas. As for drought tolerance, I cannot make a direct comparison because I wasn’t growing both when we had water restrictions, but I am willing to bet that Zoysia is at least as drought tolerant and likely more than buffalo grass. When we had water rationing I decided to stop watering my Zoysia, it went two months without water before I took pity on it and resumed watering. And then I barely watered it. So I think it has REMARKABLE drought tolerance, and otherwise has much better other attributes than buffalo grass. With better color, shorter dormant season and is less invasive. Speaking of invasiveness, I grow a seedless Zoysia so there is no seeding about. It spreads via underground rhizomes but not above ground runners like both Bermuda and Buffalo grasses. Zoysia is easily contained by an edge barrier. It baffles me that it is never mentioned as a good alternative to less drought tolerant options. BTW, Kurapia is invasive. My close neighbor has it and has to be very vigilant that it doesn’t escape into adjacent garden areas. It also flowers and attracts bees. It doesn’t have a great green color either. It does need watering also. I also have a rather large patch of Festuca rubra that I never mow.. It is a remarkably attractive deep emerald green. It has sturdy fine textured blades that are lax and lie almost flat in swirls. It does well in full sun or part shade. It stays green in good soil and with a little shade (and not much shade) almost all summer without water. It has only one major drawback and that is it seeds about rather invasively. The seedlings do not weed out easily but are quickly deep rooted and it’s really tough to pull roots out. Of course it can be mowed and that would eliminate the seeding problem. I don’t know how well it would do as a playground for children but it is certainly something to look into.

We tried all clover in a new lawn. The first year it was gorgeous all year, although taller and leggier than we had anticipated.. 2nd year started off great and still no weeds. Then we had a drought. No problem we thought, clover is drought resistant. Not so fast. We live in the country on well water so using that to water our lawn not feasible. So, all the clover died, all sorts of weeds moved in and it looked more than sad. Not that we hadn't researched the heck out of the clover before we went that route. What we learned later after much digging on line was that if you have all-clover and can't water during a drought that the clover plants compete with each other for the little water that is there and it will die. So, would be careful about trying an all clover lawn. But if you can keep it watered you might be ok.