Ask Mr. Smarty Plants

Sorry, we would never encourage the proliferation of a non-native like Photinia x fraseri, the scientific name for Red Tip Photinia. 

In this Mississippi State University Extension Service Red-tip Photinia Almost Eliminated, you can learn some of our reasons for that stance. Here is an excerpt from that article:

"Red-tip is highly susceptible to the fungal pathogen known as Entomosporium that causes leaf spots and ultimately defoliation. The disease has all but eliminated Red-tip from the list of recommended shrubs for Southern landscapes. In fact, the disease is so widespread that one plant pathologist jokingly explained that there are two types of Red-tip, those that have the disease and those that are going to get it! So, even though newly planted Red-tip bushes may stay disease free for many years, ultimately they will succumb to the inevitable."

Frankly, we're amazed that your photinias have done as well as you say they have. Even when they are not infected with the pathogen, they are not ordinarily a long-lived shrub. The fact that they grow very fast is, of course, considered an advantage when you are landscaping a new property; unfortunately, fast growing woody plants seldom live very long, have weak wood and are frequently subject to pests and diseases. 

The scientific name is Photinia x fraseri, the "x" meaning it is a hybrid. Photinia, itself, originated in China and Japan. These two facts mean that it is not a native to North America, and therefore out of our range of expertise. At the Lady Bird Johnson Wildflower Center, we are committed to the care and propagation of plants native not only to North America but to the area in which they are being grown. A plant long acclimated to a climate, rainfall and soils wil require less fertilization, water and maintenance.