This is where the majority of my cuttings are rooted.
The Dewpoint commercial type propagator has now been used for four years so the very high initial cost has now been somewhat justified.
The principle is based on a 100% humidity-hence the name of the piece of equipment (DEWPOINT), but the secret is that the leaves do not become wet, no wilting, and with the thermostat bottom heating supplied I suspect just about any softwood cutting could be rooted .In addition- two lighting tubes, an integral part of the propagator, provide overhead lighting( set by me for 16 hours a day).24 hours is possible, but some plants need “sleep” to succeed.
The shortest time for a Florist pansy/viola cutting to root has been 11 days. Most have rooted by day 28 .Failures do happen but I suspect the majority are my own fault for choosing the “wrong” type of cutting material, and sometimes disease cannot be seen if in the makeup of the mother plant.
There are tasks that need to be done- after about nine months of continuous use, cleaning out the plastic water holding tray and replacing the bubble air hose and cleaning the air pump filter is advisable
Maintenance during the rooting process is minimal , and one could leave it running for weeks , if away on holiday for example.
It needs to be sited indoors ,spare room or garage perhaps, as a greenhouse would be far too hot most of the year.
One interesting point is that with 100 humidity SPIDER MITE ,if present ,relish the dampness and heat, completely dispelling the myth that they do not like damp conditions.
A jet of water might dislodge but they do not seem worried in the slightest about breeding and thriving in these so called anti spider mite conditions.
We live and learn.