Pathosis Position

Pathosis Position

Current Conditions

Our slow to start and fluctuating spring has earned the region an average of 82 growing degree days. The cool, overcast, damp days have given way to warmer than average temperatures but are forecasted to level out into average weather for the time of year. Soil temperatures have increased and are able to maintain proper levels for continual vegetative and root growth.  Much of the northeast has received approximately 1 to 1.5 inches of rain, so newly planted trees should continue to be watered regularly. Extended floral blossoming continues and warming temperatures coax late bloomers out of their buds. However, it is not only plants that capitalize on spring weather, diseases get a boost from warmer, damper, sunnier days as well.

Dilemmatic Disease

Many diseases are coming into their own in late spring as air and soil temperatures rise and days grow longer and sunnier.  Due to complex life cycles, morphological stages and multiple hosts diseases will appear at different times of year on different plants, making identification and treatment tricky. Discussed below are some diseases currently showing up, this is by no means, an all inclusive list. Your arborist will be able to properly assess disease on your landscape and recommend treatments and/or preventative measures.

volutella pachy stem

Pachysandra volutella blight will affect stems and leaves of established populations and transplants. Infected stems will become dark brown and black and die. In very wet conditions orangish-pink fungal spores will colonize the surface of dead stems.

volutella pachy leaf

Brown and tan spots will develop on pachysandra leaves and eventually spread over the entire leaf. Concentric line patterns may be visible. Volutella may be effectively treated with fungicides, if the timing is appropriate.














diplodia twig

Diplodia is caused by Sphaeropsis sapinea, kills shoot tips and branches on many species of 2 and 3 needled pines. Needles of new shoots will brown quickly and shoots will die. One of the first visible symptoms of an infection is oozing resin from new growth in the early spring.

diplodia pine

The disease persists, killing entire branches but hold their needles. Pruning out diseased branches may also help, but pruning tools need to be sterilized in between cuts to reduce the possibility of spread.
















Needle blight occurs on arborvitae, cypress and juniper species turning tips of twigs and ends of needles brown or grey. Black, pimple-like fungal fruiting structures may develop on needle surfaces.





Stem and twig blight caused by Phompsis spp. fungus causes branches and twigs to brown and die, it can invade and girdle larger branches. In places where dead twigs meet live growth small, black, pimple-like, fungal fruiting structures will form.









Diseases can be devastating to plant growth cause stress which persists into the next growing season.  However, there are treatments and preventative measures to be put into place. Consult with your arborist to identify an disease problems on your landscape and develop a treatment and prevention plan structured for your plants particular needs.