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. After a certain age, often years, some plants may even have difficulty producing cutting viable to produce roots.
Some plants produce better rooting when cuttings are taken from juvenile parts of the plant.
When taking shoot cuttings from the same stock plant at the same time some cuttings may have different rooting ability. While a cutting may be young in growth age they may be old relative to the stem from which the cutting is taken. Physically young cuttings taken from the top of a two year old tree branch may exhibit root initiation performance as if they were two year old cuttings. One reason may be the position of the shoots on the plant. Current years shoots may root different from second year shoots.