Abstract: A spring tooth harrow for land treatment has an improved spring tooth and an improved tooth attachment clip; the tooth has a tine, a helical coil spring, and a mounting lug having an inboard leg, a semi-circular medial leg and a straight outboard leg, the legs are co-planar and have a divergent angle between them; the clip is L-shaped and has a first leg with a rear shoulder and a fastener aperture and a second leg with a taper divergent towards the first leg; the clip second leg goes in between the lug inboard and outboard ends and biases the tooth into proper position, the second leg also absorbs a significant part of the lateral loads upon the tooth, and applies these loads directly to a structure of the harrow.