Fugus on shrubs and trees
My shrubs and trees have been inundated with a fungus. It started small but it now killing everything. Since we are suppose to climb out of the freezing temperatures into the warmth, I was wondering what I need to get to start spraying to try and save some of the bigger trees that are now being attacked. I lost just about all the forsythia, boxwoods and roses. It took out the hybrid cherry trees. Help. I am told it comes from the local farms, but not sure how true that is. Lower Caroline County - Bethlehem area.
Caroline County Maryland
Do not spray any pesticides unless you have identified the disease or pest and you know what you are spraying for. Most diseases/pests are host specific and do not affect all trees and shrubs. It is also possible that you may be dealing with abiotic issues such as drought, too much moisture, poor soils, etc. In some cases no treatment may be necessary.
In general boxwoods are susectible to several fungal diseases as well as insect, vole, and abiotic issues (cultural and environmental). See our website and publication for symptoms and causes http://extension.umd.edu/hgic/boxwood-culture-and-diseases-including-boxwood-blight
Forsythia can be subject to several fungal diseases.
Roses are not easy to grow in MD. The are subject to several fungal diseases such as powdery mildew, black spot, rose rosette, https://extension.umd.edu/hgic/trees-and-shrubs/common-diseases-trees-and-shrubs as well as insect pests like cane borers and rose slugs. https://extension.umd.edu/hgic/rose-slugs-shrubs
Cherry trees can be susceptible to shot hole fungus http://extension.umd.edu/hgic/cherry-shot-hole-flowering-cherries
and brown rot http://extension.umd.edu/hgic/brown-rot-ornamental-cherries-trees
Send us photos as soon as you notice symptoms in the spring so we can see what you are dealing with. Send photos of the whole tree or shrub, around the base, and affected foliage.
here are some pictures... Today with the temperatures climbing it has exploded onto every tree and bush in the yard. Help before we loose all the trees and all the shrubs.
We viewed your photos. This looks like lichen on the tree trunks.
Your trees look old and mature. Lichen may grow harmlessly on mature trees and are not a reason for decline. They are considered a good indicator of air quality. Leave them be. No control is necessary. Look at photos on our website.
In the second photo it looks like there may be some limbs that are half dead. If you have dead limbs, prune during dry weather. Scratch the branch with your fingernail and look for green tissue. If you see it, the branch may still be viable.
In general cherry trees are not long lived trees. They can be susceptible to borers, cankers, etc. All you can do is prune dead wood. Monitor the growth of your trees this growing season.