I was plunking my hair when it was two or three inches long, so I have a hard time imagining hair which is too short to plunk. If you're using the right technique, scrunching your hair with gel in it while upside down, then lowering your head onto the plunking towel/T-shirt, the curls should stay scrunched as you do it.
Peace,
Morgan

Baby Fine 3B, low porosity, normal density and elasticity
CGing since July 2008