The caller stated, “My neighbor had a fungal disease on his photinias a few years ago, and I am worried they are infecting my trees and bushes.” This is most likely a fungal disease called Entomosporium Leaf Spot. This is a leaf spot that has been very destructive of photinia. It begins as small purple dots on either side of new leaves. As it progresses, the spots enlarge and turn brown to gray in the center. Spots will keep a dark red to purple halo around the dead center.

Most diseases and even pests of plants tend to be host specific. This means that my dogwood leafspot will generally not infect my boxwoods and the aphids on my okra will not spread to my white oak. That being said, entomosporium is so prevalent in photinia that N.C. State Extension recommends not planting it in a home landscape. This fungal disease will infect other bushes such as Indian Hawthorne. Have you ever walked into a building and noticed the defoliating Indian hawthorns? Maybe that is just me — my wife says I am a real plant nerd because I notice these types of things everywhere we go! Entomosporium can affect other hosts, in addition to photinia and Indian hawthorne, such as pyracantha, pear, quince and loquat.

A fungicide containing the active ingredients chlorothalonil, myclobutanil. Propiconazole or triforine can be used according to label instructions. However, the best course of action is to plant resistant varieties or cultivars. In the instance of photinia, no cultivars have shown good resistance. Indian hawthorne, on the other hand, has several cultivars from which to choose that have great resistance to this disease.

Sanitation is key to preventing any disease in the landscape. Clean up any fallen leaves, remove and dispose of infected leaves from the shrubs. Proper spacing allows airflow in between the shrubs, lessening the moisture period after rains events and dew. This is essential to preventing fungal diseases on all plants in the landscape. Watering the soil and not the plant is another cultural practice that can limit disease prevalence in the landscape.

Now, back to the call of the week: the caller was concerned about her poplar trees and camellias. This season, we have been in a fairly severe drought at times. One of the quickest trees to show drought stress in the landscape is tulip poplar. Their leaves turn yellow just as if it was autumn. This is their defense mechanism against drought stress, it is called eco-dormancy, and is purely an abiotic (non-biological) response to environmental conditions.

Camellias have trouble of their own. Two years ago, we had very cold temperatures here in eastern North Carolina that affected many camellias. The response mainly affected the older leaves on the shrubs, turning them dull green, then a reddish bronze color and they eventually died. Pruning the dead branches later in the spring is the best practice to help the shrubs recover. Camellias also have pest problems such as tea scale, leaf miners and exobasidium leaf galls. While not detrimental to the overall health of the shrub, these pests can be unsightly to say the least.

If you think you may have one of these issues in your landscape, call your local county extension center for details and a proper diagnosis. If you have a question to submit, please email Gene Fox at gene_fox@ncsu.edu. Those having trouble with growing in your home landscape can call the Extension office at 252-946-0111 and speak to an Extension Master Gardener volunteers, Mondays and Wednesdays between 10 a.m. and noon. Learn more on Facebook at the Blacklands Area Horticulture page or visit the Extension Office located at 155 Airport Road in Washington.