My Gardenia Has Yellow Leaves!

“My Gardenia has yellow leaves!” This is a phrase heard almost daily in the nursery industry. People love Gardenia flowers, but have difficulty growing the plant in the Santa Clarita Valley.
To achieve success in growing Gardenias, it is necessary to understand their cultural requirements. We can not control the climate. We can, however, control where in the yard we put them. Gardenias grow very well with good morning sun until about noon, then shade the rest of the day. An eastern exposure should be ideal.
Gardenias do not like our alkali soil. In light of this fact, we should not use much of it! Replacing our native soil with an acid type mixture, such as Azalea/Camellia mix is ideal. Use about 80% of the packaged mix, and only 20% of your garden soil. Feed the plant with acid forming fertilizers from March through October.
Now for the hard part, watering. Gardenias do not like our water, which is alkaline and generally high in salts. Since we cannot change the water, it is necessary to change our watering habits. Water your plants deeply and thoroughly to keep the salts soluble, leaching them below the root zone. Soak the entire root zone–just don’t do it too often! Gardenias do not like to have their roots continually wet. On the other hand, do not let your plant reach the wilting point. As with any new plant, create and maintain a watering basin around the young plant until its roots are established.
Gardenia varieties grafted onto G. thunbergii rootstock have shown promising results in local gardens. Monrovia Growers brand is currently offering many of the most popular gardenia varieties on grafted rootstock.
For additional information, consult the Garden Pros at Green Thumb Garden Center, 23734 Newhall Ave., in Old Town Newhall.