Gardenia Propagation

Cuttings

• A portion of a gardenia branch can be cut from the plant and induced to produce roots. Perform cuttings using only clean, sterilized tools to prevent the spread of diseases like canker. Take cuttings from terminal stems where wood is about six to eight weeks old. The cutting should be about 4 to 5 inches long and have two or three sets of leaves. The cutting can be dipped in a medium-strength rooting hormone before it is placed in a rooting media of half peat moss and half sand or perlite. Cuttings will root best if grown using a mist system or humidity chamber and may take between one and six months to send out roots. Cuttings tend to root most successfully when they are taken in June, July and August.

Grafting

• A desirable gardenia specimen can be reproduced by grafting a portion of it, known as a scion, to an established rootstock. Once the rootstock is at least 6 inches tall and as wide as a pencil, it can be cut diagonally for a splice graft or in a wedge for the inverted saddle graft. A similarly sized stem from the desirable gardenia is cut to match the rootstock. Then, the scion and rootstock are placed together, bound and covered thoroughly to prevent drying. After the graft is performed, the new specimen should be kept in a shaded environment with as near to 100 percent humidity as possible. The graft should begin to callous over in a few weeks.

Air Layering

• Air layering is generally used only when a plant fails to root by means of less complicated propagation methods. Air layering involves wounding a branch of the gardenia before wrapping it with a suitable rooting medium. To wound the gardenia, make two parallel cuts around the stem about 1 1/2 inches apart, cutting only through the bark and cambium, then make one long cut connecting the two cuts and remove the piece of bark. Envelop the wound with a handful of damp sphagnum peat moss, tying the moss on with string or twine, if necessary. Wrap the portion of the stem with the moss snugly with a sheet of polyethylene film and tape the ends of the film shut and to the stem with electrical tape. Once root have emerged and are visible through the film, remove the rooted portion of the stem and plant the gardenia in a suitable medium with the film removed but the moss ball still intact.

Seed

• Gardenias can be grown from seed; seedlings are commonly used as rootstock for grafting. Collect seeds from a gardenia seed pod and sow the seed into flats that contain a mixture of half peat moss and half perlite or sand. Seeds have erratic germination and germinate slowly, taking up to three months. Seedlings are ready to have a scion grafted to them when they are at least 6 inches tall and about as thick as a pencil.