Locate a parent plant that is healthy and has plenty of new growth to take cuttings from. Many of your family and friends probably have large Gardenias that are in need of trimming and shaping every year in order to maintain a limited size. New growth can be as much as 12 inch shoots each season. The best time to take cuttings (in Northwest Florida at least) is between July and October, after the blooms have fallen and new shoots are beginning to harden off. Take as long a cutting as you can and always cut just below a set of leaf nodes. The longer section of NEW growth you start with, the bigger the finished/rooted plant will be. From the tip to the cut there should be about 4 or 5 sets of leaf nodes. Cut at an angle to increase the surface area of the cut and give the plant the most chance to form roots quickly. Later, I will tell you another important step to help encourage root growth, but for now, just get the cuttings.
So, step one will be to secure the softwood cuttings from a healthy parent plant.
Step two is to prep the cuttings for rooting.
Before you can do that, you need a simple propagating chamber that can supply the cuttings with a humid environment for 6 to 8 weeks while the roots develop. Many people would suggest rooting gardenias in water. I have tried this method and do not recommend it because the water roots are so tiny and tender, they often will not survive for long when planted out, or will not support the plant in a healthy state after transplanting. A simple way to root Gardenias is to stick the cuttings in dry sand, cover with the top part of a 2 litre plastic bottle, and water the sand periodically to maintain humidity. This is the way I started out propagating and it works well, however, if you want more plants at a time, you may need to build a propagating bed. I currently use a cold frame that my Brother built to use as a solar water heater. I simply removed the tank and filled with about 6 inches of sand from my driveway. Check it out.
Here is a view inside.
The Gardenias are to the right. There are some other cuttings to the left. Note the media is just sand that is kept moist for 6 to 8 weeks while the cuttings root. You can tell if the humidity is high enough by the amount of condensation on the glass. Trial and error will dictate how often you water the sand during the process. Below is some cuttings that have rooted and are potted up in cups and are being hardened off before planting.
Where were we, oh yes, Step two..... prep the cuttings for sticking in sand. Strip the leaves from all but the top two nodes. The leaves that are left will need to be fed water during the rooting process, hence, you will have to wet the sand in your propagation chamber more often if you leave more leaves. I sometimes remove all the leaves accept for the tip leaves (2) but I wanted to try and root some with more leaves in order to have full plants when rooted and planted out. You just have to keep a check on the moisture level in the soil and add water as needed. The soil must not dry out or the cuttings will die. Also, if you make your own propagation chamber from wood, seal the wood or line the bottom with plastic to prevent water from being wicked out of the sand. I have lost cuttings that way. The same applies to sand in a pot or container that is covered by a plastic bottle. Dry roots/cuttings will die.
Prep the cuttings by removal of leaves as above, then use a knife or similar object to wound the cutting on two sides, about 2 inches at the bottom of the shoot where roots should be. The wound will scar and produce roots. Scrape deep enough to expose the cambium layer. Dip the cuttings in root hormone and stick them in the dry sand. When all of the cuttings are positioned, water the sand well. You only need to stick the cutting deep enough to cover the wounds you have just created, but water the sand well. Then, water the sand well. and finally, water the sand well. It is important to wet the sand deeply, beyond the depth of the cuttings.
Mark the calendar on the day you stick the cuttings and check them in 6 - 8 weeks for roots. New growth does not signal that roots have formed! Do not tug on the cuttings, dig one up and tap or rinse the sand off to check for root growth. Pulling the cutting out will only damage the roots. If you have followed the instructions above well, you will not have to look very close to find roots. Good luck!
