Propagation Of Hibiscus

Species hibiscus can be grown from seed and the offspring will be true to type. The species can be reliably propagated in this way (some of them self-seed prolifically), although the time from seed-sowing to a shapely bush in flower is a lot longer than the faster method of taking cuttings.

Hybrids, as distinct from species, cannot be propagated by seed to produce identical offspring. This is because the parental complexity of hybrids results in variable seed, with some seed reverting to one parent and others to an earlier ancestor, and so on, so it is possible for new progeny to resemble only slightly their seed-donor parents.

Propagating species by seed

Germination may be hastened by scoring the surface of the seed with a razor blade, but the procedure is not essential. Use commercial starter mix in a shallow container. Press one or two seeds into the mix to about the same depth of the seed itself, and water well. Keep out of the sun at a temperature of 68°- 77° (20-25°C). Check that the mix stays moist but not wet. After about three weeks a new seedling, or two, will appear and shoots will develop. Once it has reached about 8 in (20 cm) high you can pot it, and flowering will be about another five to twelve months away, possibly longer.

Other propagation methods

Other methods of propagation include grafting, air-layering and tissue culture. These techniques call for some expertise, and most amateur gardeners would prefer to leave these to the specialists. Tissue culture, for example, the modern method of mass production, can only be done in laboratories.  Fortunately there's a simple method of reproduction: taking cuttings.

Taking cuttings

In late winter or early spring, just before the shrub begins its first warmer-weather flush, select a hardwood stem for cutting. Nurserymen intent on production yields may take cuttings of softwood tips, particularly if parental material is in short supply, or medium wood, or hardwood, or all three of these, but the home gardener will find hardwood cuttings easiest to handle. Select the best stem you can find: straight, smooth, as thick as a pencil or thicker, and unblemished.

Now, using scrupulously clean secateurs, cut immediately below the node (i.e. where leaves or buds join the stem) at an angle of about 45°, and then trim to about 5-6 in (12-15 cm) long; professionals use a sharp knife for this task. Remove any leaves. Place the cuttings in a pot of coarse material, such as sand, perlite, or a mix of these, and include a little peat -about one part sand to one part peat. Don't push the stems deep into the medium -1 in (3 cm) is plenty. Bottom heat is not necessary, nor is rooting hormone powder.

Place a hoop of wire over the pot by pushing each end of the wire down the side, to create a support for the plastic covering you should then attach. Position the pot in a warm spot away from direct sun. Warmth is important, even if bottom heat isn't (of course, commercial propagators always use bottom heat), so if the climate is cool, wait until the weather heats up or take it indoors. If the medium was well-watered at the start, further watering shouldn't be necessary, so you can forget all about the cutting and go forth into the garden. If you forget for long enough, you'll be agreeably surprised at seeing your cuttings when they've struck. This will take about 6 to 8 weeks if an optimum temperature of 68°-77°F (20° to 25° C) is maintained, and longer in cooler temperatures. Let them develop more green growth (another month or so), and when they start to really shoot away, put each one into its own individual pot. Should the strike be so successful and vigorous that the cuttings' fine roots are enmeshed, separate them gently by immersing first in clean water. Pot into a mix with some nutrition in it, using such ingredients as compost, peat, commercially bagged all-purpose potting mix, or quality loam with well-rotted manure -together with a generous scoop or two of coarse sand for drainage -and water well.

It is in these individual pots that your new hibiscus shrubs will start to develop. Keep them out of direct sun and watch over them until you feel they've grown enough to be ready to plant in the garden, or into the larger containers if you intend to keep them in. Before their final move outside, expose them gradually to more and stronger sunshine over a period of several weeks. Remember that slugs and snails are never interested in mature leaves -they much prefer the tasty new leaves of an infant plant, so be vigilant.