Ask a Question
Notify Me On Question Update
Email this Question
What is anthracnose?
Rate This FAQ
Anthracnose is a fungal disease that attacks trees during cool, wet springs. Evidence of the disease appears each year, but it is much more damaging in especially rainy weather. The name sounds a little intimidating, but the disease is not normally fatal. Consider this information.
The fungal disease attacks a number of trees in northern Utah, but those most affected include maple, sycamore, oak and ash.
Anthracnose first appears on the leaves along the veins. It looks like small water-soaked lesions, and the veins turn black on the underside. The fungus can also attack areas between the veins. Severely infected leaves eventually fall from the tree.
Serious infestations can also infect twigs and branches. As the disease moves down the leaves, it attacks the twigs, causing them to become discolored. When damage has been continuous over time, the disease can move through the tree and kill small branches. However, this is not common.
Anthracnose spreads and thrives in wet conditions and spends the winter months hiding in fallen leaves and dead twigs. In the spring it is spread by rainfall and wind. It can also be spread by regular over irrigation.
Normally, control measures are not needed for anthracnose. Since the disease requires moisture to move and cause damage, the trees usually recover, and new leaves fill in. The tree may look sparse for a few weeks, but most look better by mid-July.
The best way to reduce damage from anthracnose is to clean up leaves as they drop, particularly in the fall. It is important to also remove and destroy or dispose of any dead or diseased twigs and limbs.
Fungicides should be applied in the spring. They work best if put on before the disease spreads and causes damage. Unfortunately, it can be anyone’s guess which year the spray will be needed. If you have ash, oak, sycamore or maple trees, ask your local nursery or garden center which fungicides are registered for this disease, and be prepared.
Be patient with trees suffering with anthracnose. Although they look straggly now, new leaves should reappear and fill in soon.
Submit Your Suggestion
Other Questions In This Topic
- I have a very large, beautiful Cottonwood tree on my property, that is near the property line with my neighbor. She wants to put in a new fence, because the tree has been pushing up the posts for her old fence. The fencing company has said that they can put in a new fence, but they will have to "shave off" a bit of the tree trunk and possibly some of the root near the surface of the ground. I am worried that something like that could lead to the tree getting sick or dying. I want to keep peace among neighbors, but it would be a disaster and very expensive to lose the tree because of something likethis. Can you please tell me if a Cottonwood tree is hardy enough to withstand such a "shaving" procedure?
- Why are my older pine and spruce trees dropping their needles?
- I have a large Pinion pine that we trimmed back the lower branches on last fall, The grass is not doing well there due to limited light, could I add a flower bed there instead, and if so what type of plants would do well in my VERY clay soil. Also isnt' there something about not planting flowers over/next to a tree trunk? thanks
- My euonymus has a white powdery film on the leaves, what is it?
- We will need to establish some native plants. How much do we have to water Greasewood, Four-wing Saltbush, Rabbitbrush, Green Ephedra, and Spiny Hopsage in #10 containers? We also have two trees, a 5'Utah Juniper and 3' tall Gambel Oaks to water. I understand it best to lightly water for a year and then wean them off in the wet season. Is this correct?
- We have a 3 year old maple tree that seemed to be doing great, but never lost it's leaves last fall. It showed no sign of life this spring and we were ready to replace it. A week or so ago it started sending out leaves at it's crotch. I'm pretty sure the top of the tree is dead. Do we cut it down to it's crotch (losing at least 8 feet of branches)? Will it regain a shape and will it be strong enough to survive the wind? What should we do with this tree?!
- I have a very large Honey Locust tree on the West side of my house. It is dropping leaves and has a lost more dead branches then the previous years. What problems should I look for and what can I do to save this precious tree?
- I have grass growing in my myrtle(I know it has another name but I can't think of it) and I would like to get out of there. How can I do that without killing the ground cover that I have?