I have divided arums in both fall and spring without problems. However, you will get lots better clumps if you leave them alone for as long as you possibly can. They are my favorite plant for winter interest here. I particularly like them mixed with evergreen ferns and evergreen carexes. I have grown cyclamen too and I love them. They simply must have perfect drainage and as dry a summer as possible. Depending on the variety, they bloom in late summer through early winter and the gorgeous leaves stand through the winter. If you don't have the right conditions for them, Callaway Asarums are a great substitute, though they don't bloom. Other plants I enjoy during the winter are dwarf Nandinas, hellebores, camellias, pansies (of course), ornamental kales and mustards, and very early blooming narcissus. My Grand Primos are at least six inches tall right now. I have known them to bloom as early as the week after Christmas, but that depends on weather.

Some backbulbs will grow a new lead and roots, others will not. People place them base down into damp sand or fine Cymbidium potting material to see what happens. Some growers throw them away unless they are dealing with a valuable plant. Divisions should be a minimum of the newest lead and 4 growths back from that lead. Optimum time for repotting, division is spring. I use a mixture of treated pine bark and coconut chunks plus a small amount of Diatomite. There are a zillion Cymbidium potting mixture recipes, perhaps you can buy some ready made up potting mixture in CA. I clean leaves with Eco oil and water which is a concoction of Canola oil, plus eucalyptus oil. Something similar is certainly available in the USA.

I've moved painted ferns at different times of the year and in some cases they split apart on their own. All parts survived and prosper. I don't have any maidenhair ferns growing now. Tried once, drowned it and never bought again. I should try it again. Re: Cyrtomium. I've read somewhere that they are easy from seeds indoor. Maybe instead of dividing it you want to try it from seeds which holly ferns produce in abundance. Just a thought.

I have always divided in the spring as soon as the sprouts appear big enough to be seen properly. Interesting info keesha! I am going to have to look closer at the hosta this year and see how they look. Maybe I will have to give it a try. I never really thought about whether they were nicely rounded mounds.....I am kind of a 'plant it and be grateful it grows' kind of gardener,:) so unless something is extremely unruly or floppy, I don't really think about it, although I am always impressed when I do see a beautifully shaped plant in the garden. gg