Chickweed is not only an extremely invasive weed, crowding out all other plants in your yard, but it is also extremely fast growing and can spread to cover your entire yard in just a few short weeks. The best time to kill chickweed is when you first notice it, but if this fast-moving pest has already gotten a foothold in your yard, there are still steps you can take to control and even eliminate it entirely.
Water your chickweed thoroughly to soften the soil, and then pull up as much of the chickweed as possible by hand. Wear gloves when pulling chickweed. Chickweed appears strong on the surface, but comes up easily when pulled. Pull as many roots as possible. Discard or burn the pulled chickweed.
Aerate your lawn. This can be done with a rented machine designed to poke holes (at least 2 inches deep) throughout your lawn as you roll the machine over your grass, or you can even use a spade or an ax to gouge 2-inch deep holes every 12 to 14 inches. The holes allow fertilizer to penetrate to the ground roots faster.
Spread a generous layer (at least 1/4 of an inch) of lawn fertilizer with a turf builder and weed killer included. Talk to your garden center about the best type of fertilizer for your area. There are many different brands that work well. Follow the manufacturer's instructions for when to water and how much to water. There are different watering requirements for different brands of turf-builder fertilizer.
Water your lawn every day for 14 days, keeping the ground moist but not saturated. At the end of 14 days all of the remaining chickweed should be dead.
Apply 1/8 inch of the combination fertilizer, weed killer and turf builder to your lawn 14 days after the first fertilizing. Continue watering every day for the next 14 days, keeping the ground moist but not saturated. At the end of this second 14-day fertilizing period, your lawn should be green and healthy and the chickweed should be gone.
Pull out any chickweed you see as soon as it sprouts.