With this scarifier for ride-on mower, even large lawns can be quickly and easily cleared of moss and other weeds and aerated efficiently so that the lawn can develop a better and denser growth. With the coupling, the lawn comb can be easily and safely connected to the ride-on mower or lawn tractor, provided that it has a coupling device. In the case of particularly dense growth of moss, the scarifier can be weighed down with additional weights (not included in the delivery) so that the galvanised steel springs rest on the lawn with higher pressure and demoss it even more.