TallyMan wrote:
Waste of time, it will just go mouldy and maybe harm the plant causing it to "damp-off". Hormone rooting powder is best applied to bare cut stems before planting them. Many plants root quite well without the rooting powder anyway.
Just take care not to overwater, but to keep the soil just moist. Covering with a polythene bag can help rooting by retaining moisture, but it should be removed daily to let fresh air in.
A lot depends on what plant you are actually trying to grow from a cutting.
I grew a nice shrub rose from a cutting with the hormone powder applied at the' node' and put a ziplock baggy over it with a few perforations in the top for air.
With a warm soil temp. it grew nicely.