I’ve been studying my lawn lately.
No seriously, hear me out. My lawn is interesting.
See, I’ve got five major species vying for dominance of the dirt: There’s the grass, which I want to encourage, and then there are the clover, the creeping charlie, the dandelions (damn them!), and these ugly ass broadleaf plants. They require very different methodologies to control.
Clover and creeping charlie are spreading vines which send down roots when a node touches the ground. They grow incredibly fast and cannot be removed by tearing them out. This is primarily because of the fact that they seem to be able to regenerate from any scrap of tissue left anywhere near the ground. I’m told that the most popular way to eradicate either is to go nuclear with chemicals (use 10% or stronger vinegar if you want to be all granola and unshaved about it) early in the spring. This has the side effect of killing ALL the plants in the treated area, but you can then reseed with the ground cover of your choice.
More reliable, but harder, is to modify the environment such that the grass will legitimately outcompete the vines. Grass has dense, spreading roots and will tend to win on well fertilized, decently loose soil. The vines have puny roots and are basically scavengers. If the soil is hard packed or not very rich in nitrogen, the vines will win. So, I’ve been fertilizing (compost and blood meal), aerating (pointy stick), and letting the grass go a little longer so that it shades the clover and kicks its ass.
Dandelions and broadleaves are a totally different story. You gotta dig them out. The most effective method I’ve found is to insert a trowel vertically next to the center of the plant, and loosen the soil by wiggling it. Then the plant pops right out with a gentle pull. This has a pleasant side effect of aerating (de compacting) the soil as you go.
Never, ever, put weeds in your compost. It’s just dumb. You get lots and lots of new weeds.
I have no idea how to get rid of crabgrass. The folk remedy is to dig it out, including about a foot of soil on any side of the plant, and then burn it on concrete, on a day when the wind is blowing away from your property.