Question: I saw your articles touting the benefits of clover. I thought of it as a lawn weed, but you changed my mind. So tell me, without ripping out the sod, how do I replace my blue fescue lawn with clover?
Answer: Since you don't want to remove the existing lawn, you'll want to overseed it with clover seed. White clover (Trifolium repens) is the most available seed; look for bags of it at feed stores. Read about clover's benefits.
At your first spring mow, cut your lawn short, with your mower on its lowest setting. Use a fine-tined metal rake to thin the lawn and remove any thatch. Try to thin the lawn enough that when you look down you see mostly dirt. Then use a broadcast spreader to spread your clover seed across the entire lawn. Clover seed is very fine, so you might want to mix it with compost before spreading it; this will make it fall more evenly, and it may also help suppress the grass blades.
Keep the soil consistently moist until the clover sprouts (7 to 10 days). Continue to supply regular water as the clover matures to about 2 inches tall. The clover will slowly overtake your lawn. You can spread more seed in the fall to fill in any gaps.