Every weed tells a story about your soil. Crabgrass likes compact soil. Cinquefoil likes poor dry soil. Dandelions like high pH. Use your soil test as a guide to make conditions favorable to turf and unfavorable to weeds. Many plants you might consider weeds are beneficial to your lawn and useful to humans. For example, clover helps make nitrogen available in the soil, and plantain can be applied to the skin to soothe insect bites. And a diversity of species leads to lawns that are more hardy.