17. I've seen chemicals that claim to improve root formation on cuttings. Do these work?

There are several hormones that are used to assist root formation on cuttings. The most common is Indole butyric acid (IBA) although Naphthalene acetic acid (NAA) is also used, sometimes in combination with IBA. The products are usually available as powders in several strengths (softwood, medium wood and hardwood). Sometimes the chemicals may be available as a gel or in liquid form.

Do they work? Most experienced growers would say "yes". Many would also claim that the liquid formulations are superior to the other types but hard data is not readily obtained. One fact to keep in mind whatever the formulation is that the hormones have a limited shelf life and should be kept in a cool, dark place when not being used (eg. a refrigerator).

Root-promoting hormones are applied to the base of a cutting. This is a talc-based form. [25k]. Click the thumbnail image or highlighted phrase for a higher resolution image.