I have several varigated new guineas that I would like to overwinter. They are quite large. I would like to cut them in half and repot. Could I just cut them in half? I have started from cuttings, however never tried the halving.
These are one of the easiest plants to propagate from cuttings, the best way I know is the use clean knife, I like a craft knife as it is razor sharp and has a retreating / withdrawing blade, but
you need to use with care due to the sharpness of blade, must wipe blade after use or you can spread bacteria from plant to plant.
Anyway, cut stems just under a leaf axle, cut clean and have no ragged edges, recut if need be, remove the lower leaves and just stick these cuttings in clear jar or glass of fresh water, these normally show roots after a couple of weeks, IF the water turns green, remove the cuttings, gently rinse under cool running water and replace into fresh water in glass. once you feel the roots are large enough to separate the cuttings, pot up into POTTING compost specially for cuttings or seed growing. This compost from garden store has been sterilised and is more free draining than ordinary compost.
The plants can be potted up into larger pots come year end depending where you keep them over winter, IF indoors, keep the compost JUST DAMP in no more, you only want to keep the plants alive in no more. If you have more room, keep the plants well ventilated and in GOOD LIGHT, not direct sunshine or the plants will wilt and die.
Come spring when the plants have made more good roots, re-pot into better soil and either use larger pots or grow where you know they will thrive.
Hope this helps you out and you have much success.
I would do both. Take enough cuttings that you will have pruned the plants to half their current size. Then, when the new growth starts you can further cut back if needed. In the mean time, if the heavily pruned plants do not make it you will have plenty of cuttings coming on for the spring.
I mean a division through the center of the plant, turning 1 plant into 2. I have seen postings on the web that this will work. I have taken cuttings and once they get going I will try to divide the plants from which I took the cuttings.
I do not think that will work unless the original plant was really 2 or more in one pot.
ONE impatiens does not really grow into several with a dividable stem and root. While it does not really have a trunk like a tree, it does grow with one main stem from the roots, which are fine, hairy, diffuse. Not a mass that can be divided. That main stem may almost immediately branch, but the branches do not have roots, so any 'division' is really taking cuttings and rooting them.