Written by Ivy
Jan 30 2023
Here in the south, tall hedging once consisted of photinias, large shrubs. The most common photinia is the appropriately named "red tip", which is easily recognized each spring as it sends out its first flush of bright red new leaves. It has been excessively planted and used, like many popular plant species. Many red tip hedges have died or are in the process of dying out due to the widespread spread of a fungal leaf spot. Diseases for Red Tip Photinia includes Entomosporium Leaf Spot, Photinia Fire Blight, Powdery Mildew, Scab Diseases and Phytophthora Fungal Diseases.
Entomosporium mespili, the fungus that causes photinia leaf spot, is the primary cause of photinia bush diseases. This plant fungus, which is typical of most plant fungi, thrives in the cool, moist conditions of the fall and spring. It targets the most delicate new growth, which gives the shrub its name—red-tipped photinia—and the disease spreads from there. The photinia fungus won't kill the plant right away or even in the first season; instead, it will come back every year until the constant leaf drop and subsequent loss of nutrients weaken the plant to the point of death.
Nearly undetectable are the early symptoms of photinia leaf spot. On leaf surfaces, tiny, rounded red spots appear, but the lighter red spots are simple to miss due to the color of the leaves on the new growth they attack.
Days later, the spots grow larger and eventually encircle gray, dying tissue in dark, purplish circles. Because the new leaves make it simpler for the spores to take hold, the photinia fungus typically spreads from new growth to old growth.
Once the fungus takes hold in the red tip photinia, the disease's circles continue to grow and merge until large, unsightly "sores" cover the dying leaves. The black blotches inside the circular damage are evidence of the production of spores. Nothing can be done to stop the disease from progressing at this time.
A frequent issue for photinia is entomosporium leaf spot, which is distinguished by tiny red spots on both sides of the leaves. Larger, dark red, brown, or gray spots with rings around the edges are more likely to appear on older plants. The disease worsens, the leaves drop off, and the plant may eventually perish. In the winter, remove any mulch or diseased tissue from the plant bed and use pruning shears to cut off all diseased tissue.
Use rubbing alcohol to clean the shears both before and after each use. Remove the plant's lower branches by pruning. Both watering and fertilizer application should be avoided at the end of the growing season. In severe situations, thoroughly saturate the affected plants with a ready-to-use, multi-purpose fungicide until it drips. Perform this once every week until the infection's symptoms vanish.
Red tip disease is frequently caused by fire blight bacteria. It typically manifests as pale brown, watery exudate from cankers on the wood that darken when exposed to the air in the spring. There are numerous indications of fire blight, including blackened leaves, stems, flowers, and twigs. Wood inside changes color to a reddish brown. While pre-mixed copper sprays are used in place of fungicides, cultural control is similar to that for entomosporium leaf spot. It should be applied to the open flowers in the spring until they are dripping, and then again every four to five days until the plant has finished blooming.
On the photinia plant's leaves and other parts, powdery mildew frequently appears as a white, powdery substance. Additionally, it results in leaf distortion or slow growth as well as leaf loss. The best environment for powdery mildew growth is shade and temperatures between 60 and 80 degrees Fahrenheit. Effective control techniques include maintaining a clean plant bed, keeping the foliage dry, regular pruning, and fungicide applications. Apply the fungicide in the same way you would to manage entomosporium leaf spot.
Scab diseases, which occasionally affect Photinia, manifest as circular lesions on the surface of the plant and have a texture resembling a scab or velvet, on occasion. They come in a variety of colors, and more severe cases result in the death of the plant's shoots and discolored, falling-off leaves. The best course of action is to use cultural controls, such as clearing away any fall leaf debris and avoiding the foliage when watering. A suitable control strategy when used in conjunction with cultural controls is to spray the plant until it is dripping with ready-to-use horticultural oil or pre-mixed multi-purpose fungicide once a week until the symptoms have subsided. When treating leaf spot, adhere to the warnings mentioned.
Red tip photinia plants can occasionally become infected with Phytophthora fungal diseases like root and crown rot. Usually, these diseases result in the plant's leaves wilting, turning brown, and dropping off. They also retard growth and cause the wood to develop cankers, vertical streaks, and discoloration. The entire plant may eventually perish when infected areas of the wood exude red or black sap. The best methods of control involve watering plants sparingly and planting them in soil that drains well. To allow the infected area to dry out, remove the top few inches of soil from the plant's base to the top of the roots if it has crown rot. At the photinia's base, remove any weeds or plant matter that may be there.
The red-purple photinia leaf spots that can appear on the leaves are probably well known if you have red tip Photinia in your yard. This spotting is caused by a fungus, Entomosporium, and can cause damage to Both photinia and Indian Hawthorn. The loquat, flowering quince, pyracantha, and pear are other rose-family plants that might be infected. Although overhead watering for lawns that hits the shrubs is also a factor, we frequently observe severe damage following periods of frequent rainfall.
On the tops and bottoms of the leaves of infected plants, the disease first manifests as tiny, rounded, vivid red spots. On mature leaves, leaf spots may be gray or brown in the center with a definite purple border around the edge. On infected plants, spots can also be seen on the petioles and stem. Light infections may only cause "cosmetic" damage, but severe infections can cause premature leaf loss.
Thankfully, there are some steps you can take to reduce infection in the future. Start by performing any necessary pruning if your plants have already become infected. After that, shake the branches to remove any rotting or diseased leaves. The next step is the most important- clean up, clean up, clean up! Gather all of the fallen leaves and remove them along with any branches you may have pruned. The infected leaves have fungus inoculum on them, so removing them prevents possible reinfection.
We can control irrigation even though we have no control over the weather. Try adjusting the sprinkler heads so that they wet the leaves as little as possible if your lawn sprinklers are watering the plants instead of the grass. Above all, avoid drinking water at night. The more time the leaves are submerged in water, the longer it will take for the spores to sprout and infect the plant.
To ensure proper air circulation, give the plants enough room to grow. If they were planted too closely to quickly fill in, you should eventually be able to remove every other plant to help the air flow. Avoid techniques that encourage little new growth. Water only when necessary, and water first thing in the morning. Whenever possible, use drip irrigation. Pruning should only be done when absolutely necessary because it drives out susceptible new growth.
Fungicides designed specifically for this illness are a chemical control option. They will stop spores from growing and work best at preventing infection of the new growth. Two classes of fungicides should be alternated with each spray to prevent resistance. For best results, heed the warnings on the label. Our staff will be happy to recommend particular fungicides for you to use.
Different plant species have issues unique to that species, as with the Leaf Spot on Photinia. Planting a large number of the same kind of any plant may result in a maintenance headache due to insect or disease infestation. Try to mix up the types of plants used in your landscape's screening whenever you can. In addition to being cheaper than using a single-species hedge, it is frequently more aesthetically pleasing.
The first line of defense against fungal leaf spot, as with many fungal diseases, is to monitor watering and drainage. The spring and fall are the seasons with the most activity because fungi prefer moist, temperate environments. The red tip photinias' surrounding area may become waterlogged during wet spells because the clay soil that is typical of much of North Texas prevents proper drainage. The organic matter that has fallen and begun to rot together with this moisture creates the perfect environment for the growth of fungi. In order to avoid making the situation worse, it is crucial to reduce watering even if the soil drainage cannot be made better.
The Entomosporium fungus is aided in its growth by moisture as well as the fallen leaves of the photinia plant. Debris removal can slow the spread of fungus in the vicinity of the plants. Similar to this, moisture can be gathered by dense foliar growth on the inside of red tip photinias. Thin out dense areas if you can to let light and air flow through. Any areas that have leaf spot should be removed when trimming Red Tip Photinia. Removed material should be buried or disposed of in a plastic bag, especially infected leaves.
Fungicides can be used to control Entomosporium leaf spot, but the process can be costly. In addition, if environmental factors are not removed, treatment will ultimately be ineffective. A continuous process of multiple-week treatments in the spring and fall may be advised for valuable hedges. In other cases, replacing the harmed plants with less vulnerable species can frequently be more economical in the long run.
Although there is no quick fix for red tip photinia leaf spot, we hope that this knowledge can assist homeowners in minimizing the harm to their shrubs and determining whether treatment or removal may be necessary. We adore trees (as well as shrubs!) at Texas Tree Surgeons. and hedges!) and we love our customers, and we always want to give our community the best, most accurate information regarding their plants.
A fungus called Entomosporium leafspot affects woody ornamentals in the rose family. Indian hawthorne is another shrub that is affected by entomosporium leafspot. The conditions that favor the growth of this fungus are frequent fall and spring rainfall, temperatures between 60 and 80 degrees, and an active plant.
Bright red spots on the fresh leaves are the first signs, and in plants that are severely afflicted, these spots can merge to form huge maroon blotches. In minor infections, the fungus might only cause a few leaves to drop, but over time, it can eventually kill the entire plant.
By getting rid of fallen leaves to lessen the amount of fungal spores, you can help stop the spread of entomosporium leafspot if you already have a mild infection. Water in the morning if possible, and use drip irrigation if necessary to avoid keeping the foliage wet.