40 disposed inside the curve of the clip both threading over the threaded end 37 of the hook as shown in fig3 and 5 the spring mounting clips 30 are bowed stampings of spring steel each which apertures approximately in shape to the cross section of stakes 10 and 12 when the clip is slightly deflected thus for example when the stakes have a circular cross section apertures 42 are elliptical the stake is passed through the apertures 42 of the clip the elastic spring force of the clip tending to relax is exerted at the edges 43 and 45 of the aperture and holds the clip securely to the stake at a given height the clip is repositionable along the stake by squeezing together its ends 44 thereby increasing the apparent cross section of the apertures 42 and permitting the spring to move freely over the length of the stakes and then releasing the ends 44 when the clip is manually positioned at an appropriate height at least one of the stakes 10 and 12 is provided at its base with a means to measure to the next row that means may simply comprise a line adjustably attached to the base of the stake but in the preferred embodiment there is an adjustable arm 47 carrying a marker such as a wheel 46 referring to fig6 through 8 the arm comprises a rod 50 having a reduced diameter threaded end passed through a central hole in the wheel 46 such that the wheel rotatably secured to the end of the rod 50 by a.