tart cherry yellow leaves/spot, brown needles on cypress, spider(?) web on blueberries

Asked June 11, 2017, 11:11 AM EDT

Hi, Actually three questions... please your recommendations regarding spray/cure products/control. Photos attached - 1) Tart cherry trees - yellow leaves with spots/holes. And any other recommendations for spraying cherry for insects, bacteria, or fungal problems. 2) Cypress - browning of leaves/needles 3) webs (spider webs?) on blueberries and also for control of other insects, or other fungal or bacteria problems on edible fruit (blueberries)

Howard County Maryland blueberries leaf spot spider webs tart cherry possible seridium canker

1 Response

Tart cherry - this looks like cherry leaf spot. Mild, wet spring and early summer weather promotes this leaf spot. Rake up and dispose of infected leaves that fall off the plants. The disease is not serious but causes cosmetic damage. It will not kill the tree. Depending upon the weather next season the disease may not be a problem. Spraying with a fungicide is not practical as the spraying regiment begins when the new leaves emerge and continues every two weeks or so throughout the summer. See our website for more information http://extension.umd.edu/growit/diseases-stone-fruit

Leyland cypress - Based on your photo this looks like it may be seridium canker, a fungal disease. When these trees are stressed due to drought, poor planting techniques, poor drainage, etc. they can be susceptible to disease and insect issues. If planted close together there is a lot of root competition for moisture and nutrients, lack of sunlight, and poor air circulation.

Look at our website for photos and more information. There is no control for seridium canker. The brown tips will drop off naturally. Prune any dead branches during dry weather. The best recommendation is to keep the trees well watered during dry periods. Keep mulch no thicker than several inches and away from the base of the trunk. The trees grow best in full sun with plenty of air circulation and appreciate moisture during dry periods.
http://extension.umd.edu/hgic/seridium-and-botryosphaeria-canker-leylands-trees

Blueberries - You did not mention if there was just one web or is the webbing in other areas on the plants. This looks like a spider web and no control is necessary. Spiders are predators and help keep other pest insects in check. We do not see damage to the berries. See our
website and common problems of blueberries. Do not spray unless the pest or disease is identified. http://extension.umd.edu/growit/fruits/common-problems-blueberries
mh