A: Yes, it’s too early. You should wait until the grass is at least 25 percent green before scalping. Removing dead grass allows the sun to warm the soil faster. Removing thatch is a different process though. You can rent a motorized vertical mower and set the blades two inches apart and high enough to barely scratch the soil surface. Another thatch control option is regular aerating or perhaps topdressing with rich topsoil. Spreading soil on thatch hastens its decomposition and avoids the physical harm of mechanical dethatching. If you choose mechanical dethatching, don’t do it until the grass is vigorously growing in late May.