Q.Whether Sweet William will grow inside..answered my own question!!
Brought a small Sweet William in from the garden as it was to turn very cold. Planted it in a small goldfish bowl with gravel in the bottom, and sat it on the sunny kitchen windowsill. Lo and behold, now have 8 fringed blooms in pink/white. Even put a worm in the bowl and can watch it. May try with one of the yellow pansies. . . fun to do!!
Certified GKH Gardening Expert
Sweet William, as with most Dianthus plants, are ideal for containers, so with the proper growing conditions, they should do fine indoors. Glad you are having luck with yours!