Propagating hibiscus, whether tropical hibiscus or hardy hibiscus, can be done in the home garden and both varieties of hibiscus are propagated in the same way. Hardy hibiscus is easier to propagate than the tropical hibiscus, but never fear; with a little bit of knowledge about how to propagate hibiscus, you can be successful at growing either kind.
Hibiscus Propagation from Hibiscus Cuttings
Both hardy and tropical hibiscus are propagated from cuttings. Hibiscus cuttings are normally the preferred way of propagating hibiscus because a cutting will grow to be an exact copy of the parent plant.
When using hibiscus cuttings to propagate hibiscus, start by taking the cutting. The cutting should be taken from new growth or softwood. Softwood is branches on the hibiscus that have not yet matured. Softwood will be pliable and often has a greenish cast. You will mostly find softwood on a hibiscus in spring or early summer.
The hibiscus cutting should be 4 to 6 inches long. Remove everything but the top set of leaves. Trim the bottom of the hibiscus cutting to be cut just below the bottom leaf node (bump where the leaf was growing). Dip the bottom of the hibiscus cutting in rooting hormone.
The next step for propagating hibiscus from cuttings is to place the hibiscus cutting in well draining soil. A 50-50 mix of potting soil and perlite works well. Make sure the rooting soil is thoroughly wet, then stick a finger into the rooting soil. Place the hibiscus cutting into the hole and backfill it around the hibiscus cutting.
Place a plastic bag over the cutting, making sure that the plastic does not touch the leaves. Place the hibiscus cutting in partial shade. Make sure the rooting soil stays damp (not wet) until the hibiscus cuttings are rooted. The cuttings should be rooted in about eight weeks. Once they are rooted, you can repot them in a bigger pot.
Be warned that tropical hibiscus will have a lower rate of success than hardy hibiscus, but if you start several cuttings of the tropical hibiscus, there is a good chance at least one will root successfully.
Propagating Hibiscus from Hibiscus Seeds
While both tropical hibiscus and hardy hibiscus can be propagated from hibiscus seeds, typically only hardy hibiscus is propagated this way. This is because the seeds will not grow true to the parent plant and will look different from the parent.
To grow hibiscus seeds, start by nicking or sanding the seeds. This helps to get moisture into the seeds and improves germination. The hibiscus seeds can be nicked with a utility knife or sanded with a bit of fine grain plain sandpaper.
After you have done this, soak the seeds in water overnight.
The next step in propagating hibiscus from seeds is to place the seeds in the soil. The seeds should be planted twice a deep as they are big. Since hibiscus seeds tend to be small, you can use the tip of a pen or a toothpick to make the hole.
Gently sprinkle or sift more soil over where you planted the hibiscus seeds. This is better than backfilling the holes because you will not inadvertently push the seeds deeper.
Water the soil once the seeds are planted. You should see seedlings appear in one to two weeks, but it can take up to four weeks.