I'm thinking you mean how long does the cutting need to be .. since the neoprene insert is half an inch thick, the cutting has to extend beyond that - I'm noticing that vines like the passiflora shoot out roots from everywhere up and down the stem and have had cuttings only 3/4 of an inch long with just a quarter inch sticking out, root like crazy .. nodes not required and other more woody plants like Synsepalum and Radermachera make the most roots around nodes.
With and without the cloning solution, I'm astonished at how fast some plants are rooting for me - especially the stubborn ones. I gave up on the distilled water and just use water from the hose .. only mister jet clogs I've gotten is from plant material that has fallen down.
I'm already planning to make a much bigger cloning machine next year - instead of just 9 slots I'm shooting for 25.
