HI Swendy your hardy hibiscus can be de vided by cutting the plant
in half just stick your shovel in the middle of the plant
between the stalks and cut it in half straight down with the shovel then dig out from around the plant
about a foot all the way around.this will give you 2 plants
pop them up out of the ground.then just replant them where you would like them to grow.
I've done this many times with my hardy hibiscus.
your tropical hibiscus will have to come from cuttings.take cuttings from the plants
about 8 or 10 inches long remove all the leafs but the top leafs and cut the cuttings at just below the Leaf nodes. then dip or rub where you cut them with rooting hormone and make a hole in the soil in a nice big flower
pot then place the cutting in the hole or holes then pack the dirt around the cutting do quite a few in the same pot as some may die.keep the soil moist not soked.and place them in the shade.in about 6 to 8 weeks you should have some starting to root.then you cant plant
them in pots where you intend for them to grow.hope this helps and good luck with your hibiscus.your friend in gardening.mike57