Dethatching your lawn can be quite a disruptive process, which is why you need to take extra care of your lawn afterwards. After dethatching your lawn, you should your lawn. You can also follow this up by seeding the lawn or adding fertilizers. Since dethatching opens up the soil, it is a great time for you to plant new seeds. Some people also consider topdressing after dethatching as it helps avoid weed growth in the lawn. If you take good care of your lawn after dethatching, it will take three to four weeks for your lawn to become healthy.