In the 1960's-70's my Dad, Fritz Compton, would tow me in our Cirrus(Open Class) out of our 1,900' grass runway gliderport south of Miami, FLA using a 65 HP Piper J3 Cub with a climb prop. Later we upgraded to a 100 HP 1959 Cessna 150 with a climb prop. If the grass is tightly mowed, the glider pilot is very smooth on the controls (to minimize drag) and a discussion of a mandatory abort point is accomplished, it worked for us but You must evaluate and make your own decision!

My other "slow tow" experiences include aerotows in Germany behind motorgliders and the European category of ultralight airplanes.

The legendary Dick Johnson told me at a Marfa Wave Camp that he preferred a lower powered towplane because a slow climb on tow allowed him to evaluate and mark the thermals before release.

Those "old school" aviators had some interesting ideas and observations. Ask me sometime about my Dad's observation of the engine sound of an airplane flying overhead on a cold day - how the sound can indicate if thermals are present and if we should launch. Dad also observed that hawks and eagles often flew in the core of a thermal but buzzards and vultures preferred a slower climb on the edge of a thermal. True or not, soaring is primarily about the observations you make by looking outside.

Looking forward to further discussions at the SSA Convention in Little Rock, FEB 19-22, 2020.
Find me at the Soaring Safety Foundation booth near the entrance to the convention hall.