Certified GKH Gardening Expert
I'd say the best mulch depends on the type of plants that it is being used for. Sugar cane mulch is a very good way to improve the look of your garden, and keep weeds out, though. I would see no problem in using this type of mulch. The best time to mulch your garden would be in spring, unless the purpose is to protect against the winter cold. If this is what you are using it for, then there would be no harm in doing this now.