These regulators even produce rooting of some cuttings which do not self root. In 1939, using these revolutionary regulators, Dutch scientists developed rooting products and techniques now used worldwide. The manufacturer, Rhizopon b.v., is the world's largest company solely devoted to plant rooting products and technology. Select cuttings to improve rooting success. Rooting of cuttings is affected by many variables.
Some plants have different rooting ability at different times of the year.
A few weeks difference in taking of cuttings may produce success or failure. Woody plants are especially influenced by timing. When taking shoot cuttings from the same plant at the same time some cuttings may have different rooting ability. One reason may be the position of the shoots on the plant. Current year shoots may root differently from second year shoots.