Japanese Cedar: Care and Cultivation

Pestalotiopsis is a group of fungi (now often placed in Neopestalotiopsis and related genera) that causes leaf spots and tip blight, especially on plants that are stressed or kept too wet. It shows up most after cool, rainy weather or in crowded plantings with poor airflow. Look for tan to dark-brown spots that may have a yellow edge, or shoot tips that brown and die back from the tip inward. Tiny black pinhead-like dots often appear in the dead tissue—these are the fungus’s spore-producing bodies. It commonly affects arborvitae, juniper, cypress, yew, boxwood, many palms (including indoor palms), and can also occur on strawberry leaves and fruit.

Leaf spot is a common fungal disease caused by various pathogens including Alternaria, Ascochyta, Colletotrichum, Septoria, and Venturia. It primarily affects leaves, causing discolored spots that can lead to premature leaf drop if left untreated.

Root rot is a serious fungal disease that affects the root system of plants, causing them to decay and die. It is primarily caused by overwatering, poor drainage, or soil-borne fungi such as Pythium, Phytophthora, Rhizoctonia, and Fusarium. The disease thrives in waterlogged conditions where roots are deprived of oxygen, making them susceptible to fungal infection.

Aphids are small, soft-bodied, pear-shaped insects (1/16 to 1/8 inch long) that feed by sucking nutrient-rich sap from plants. They reproduce rapidly and can quickly weaken plants, causing distorted growth and transmitting plant viruses. Aphids come in various colors including green, black, red, yellow, brown, and gray. They secrete honeydew, a sticky substance that attracts ants and encourages sooty mold growth.