I like to take cuttings off the coleus in mid Sept. Plant them in 3" pots of fresh potting soil. Then I let them sit outside to start growing roots and take them inside late Sept to early Oct before it gets too cold. I just keep my in a South facing window overwinter. Nice if you can keep them under lights. They may get too tall before winter is over. If so, I take cuttings off the cuttings and pot them up inside so that they start to root before moving them outdoors. Any time you break a piece off during the summer, you can just stick it in soil and often it will root. I've gotten about 6 new plants off my trailing rose this summer just doing that.
Here you can see what my coleus cuttings looked like last fall. Looks like I did them early Sept. going to wait a couple weeks yet since things seem to be a little behind this year. About half my cuttings died over the winter, mostly because I forgot to water them enough. I always take way more than I need and always have enough to give to friends.
The thread "Cutting Addict and a few to ID" in
Coleus forum
