Snowdrift Crabapple fire blight? - Ask Extension
Hello, we got a Snowdrift Crabapple this spring. We are in Duluth, MN, clay soil. Shortly after planting, the blossoms dropped off and then the leaves...
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Snowdrift Crabapple fire blight? #412063
Asked July 05, 2017, 9:44 PM EDT
Hello, we got a Snowdrift Crabapple this spring. We are in Duluth, MN, clay soil. Shortly after planting, the blossoms dropped off and then the leaves started turning yellow and brown and falling off. At first we thought maybe a fungus, and we sprayed the tree with a fungicide for a couple weeks, but the condition has continued. The tree has grown vigorously, but the new leaves are curling up and dying. Do you think this is the fire blight? Is there any hope to save the tree or will it always be ill? What about copper liquid? I don't really want a tree I have to spend a lot of money on to keep it going. Thank you
St. Louis County Minnesota
Expert Response
Hello and thank you for contacting AaE for help.
I'm not seeing clear signs that your tree has fire blight. It may have apple scab which is another fungus but to be sure you might want to have the nursery that sold the tree to you inspect it and provide their opinion. Or you can engage a certified arborist or send a sample to the U of MN Extension Plant Disease Clinic. Here is the page containing information on the process and pricing.
Your tree should be clearing up by now especially as we get into dryer weather. Constant moisture from lots of spring rains and the launch of fungi spores at the same time makes this a common problem for Apple and Crabapple trees. The fungus causes yellow uneven edged spots on leaves which then prematurely drop. Their fruits also develop olive green to brown spots that develop into corky inedible areas and may become deformed.
The spores overwinter in the leaf litter of affected trees and are launched during spring rains. Trees can be infected by other trees with the fungus as the spores become airborne. Young wet tree leaves are the perfect environment for the fungus to develop. Keeping tree leaves wet with overhead sprinklers can provide the ideal environment. The best treatment is to remove all leaf debris from the tree as they fall and burn, bury or compost them. Also, clean up all leaves in the fall since the tree's leaves may still harbor the fungus for the rest of the season.
Your tree should leaf out again this summer though maybe not as lushly as it would have given the severity of the problem this year. Since it was newly planted this year and then possibly suffered the indignities of apple scab, it is stressed. You will need to monitor it for apple scab next year and practice good watering management to give the tree a chance to recuperate and thrive in the years to come.
For severe attacks and if there are other ornamental crabs or apple trees nearby that could possibly reinfect your tree next year, you may wish to spray again next spring. Here is a link to the U of MN Extension web page describing this disease and its management including the use of fungicides.
I'm also providing a link to the U of MN Extension web page that will give you tips on watering practices for your tree for the first few years. It's new information and I find it really enlightening since watering is important beyond the first few weeks after planting.
I hope this helps but if you have additional questions or additional pictures feel free to submit those to us and we'll take another look at it.
I'm not seeing clear signs that your tree has fire blight. It may have apple scab which is another fungus but to be sure you might want to have the nursery that sold the tree to you inspect it and provide their opinion. Or you can engage a certified arborist or send a sample to the U of MN Extension Plant Disease Clinic. Here is the page containing information on the process and pricing.
Your tree should be clearing up by now especially as we get into dryer weather. Constant moisture from lots of spring rains and the launch of fungi spores at the same time makes this a common problem for Apple and Crabapple trees. The fungus causes yellow uneven edged spots on leaves which then prematurely drop. Their fruits also develop olive green to brown spots that develop into corky inedible areas and may become deformed.
The spores overwinter in the leaf litter of affected trees and are launched during spring rains. Trees can be infected by other trees with the fungus as the spores become airborne. Young wet tree leaves are the perfect environment for the fungus to develop. Keeping tree leaves wet with overhead sprinklers can provide the ideal environment. The best treatment is to remove all leaf debris from the tree as they fall and burn, bury or compost them. Also, clean up all leaves in the fall since the tree's leaves may still harbor the fungus for the rest of the season.
Your tree should leaf out again this summer though maybe not as lushly as it would have given the severity of the problem this year. Since it was newly planted this year and then possibly suffered the indignities of apple scab, it is stressed. You will need to monitor it for apple scab next year and practice good watering management to give the tree a chance to recuperate and thrive in the years to come.
For severe attacks and if there are other ornamental crabs or apple trees nearby that could possibly reinfect your tree next year, you may wish to spray again next spring. Here is a link to the U of MN Extension web page describing this disease and its management including the use of fungicides.
I'm also providing a link to the U of MN Extension web page that will give you tips on watering practices for your tree for the first few years. It's new information and I find it really enlightening since watering is important beyond the first few weeks after planting.
I hope this helps but if you have additional questions or additional pictures feel free to submit those to us and we'll take another look at it.
