Before deciding to buy a plant in a nursery, a major consideration is often whether it has the potential to give me more plants in the future. I feel better about spending the money if I can imagine in a year or so there will be a whole row of plants from the one I bought.
Of course, all plants reproduce naturally. We just give them a helping hand. Some produce seed. Some form clumps that can be divided. Others send out runners. Some even produce their own baby plantlets.
It's amazing just how many plants will grow from a cutting. This would have to be the easiest way to get new plants for the garden.
The 3 C's of a tropical garden, crotons, cordylines and coleus can simply be cut and placed in a jar of water until the roots form. It's best to remove most of the leaves so the plant isn't using up nutrients keeping the leaves healthy, but they will usually shoot even if you don't remove the leaves.
This is what they look like now potted up.
I won't transplant them into the garden until they have a nice thick root system.
Alternatively you can just poke them into a propogating mix. (I use a mix of peat moss, potting mix and sand - roughly equal amounts) I want the cuttings to stay moist but not soggy or they will rot.
John collects styrofoam boxes from the same fruit shop that gives us the scraps for the chickens. They make great planter boxes for cuttings. Our shadehouse is next to the vegie patch so the cuttings get a regular watering while I water the vegies. They'll be ready to plant out into the garden in about 6-8 weeks.