Yes, rooting compound is a great
boost and can make the difference between success and failure. If you don't want to use the synthetic chemical version, there is a natural version -- willow tea. You could also use the growing tips of young corn leaves, but that is only available a couple of weeks after the corn is sewn in the field.
Rooting them in the
greenhouse is a good idea, because usually the greenhouse has high humidity. The enemy of new cuttings is drying out. They should be kept as close to 100% humidity as possible until they develop
enough root to keep the plant supplied with water. On a pot by pot basis, this may mean inverting a clear plastic cover over the pot after watering the cutting in good. When you see condensation on the inside of the plastic cover, then you know you have 100% humidity in there. Even if cuttings are sitting in a glass of water, if you live in a dry desert area, the air may suck more water out of the leaves than can migrate up through the cutting. This is why it is recommended to snip a lot of the leaf surface off of your cutting.
It takes a lot of trial and error, but the two things to watch for are drying out, and if you have your cutting in water, how the new
roots are developing.
