Here’s the plan: Foster immaturity, discourage diversity, squander resources. Or, put another way: Mow your grass often to keep it from flowering or putting down deep roots; poison or pull any plants that aren’t grass (call these weeds); and use lots of fresh water, nutrients and energy to keep the sward artificially verdant and trim. The result, the ubiquitous turf lawn—that sink of weekend time, that field of neighborly conformity and not-so-neighborly competition—may look green and nice, but it is a surprisingly bad idea.

Although livestock in northern countries have chewed and trampled grassy fields to closely shorn uniformity for as long as people can recall, ornamental lawns have only been around for a few hundred years. These green carpets devised for French and English g...