Knowledgebase

Sick apple tree #585979

Asked August 03, 2019, 11:32 AM EDT

Hi!  I'm a volunteer garden leader for Eddie Maestas Community Garden (a DUG organic garden) in the city of Denver.  We have a sick apple tree and I'm assuming it's a fungus.  Leaves are curled and there are only a handful of apples.  This is the second year she's been suffering.  Last year we were told it was just birds pecking the apples.  We are certain that is not the problem.

Do I use a copper fungicide?  Do I use neem oil?  We have a thriving beehive located near the tree.  Any application would need to be contained and safe for bees.

Denver County Colorado

Expert Response

It is difficult to tell from the photos what disease or insect is attacking your tree.  Coddling moth is a common disease in crabapple trees in this region. 

CSU fact sheet:

https://extension.colostate.edu/topic-areas/yard-garden/backyard-orchard-apples-and-pears-2-800/

But other diseases including fungal diseases are also seen in the apple trees. A Neem oil with an appropriate insecticidal spray would potentially provide the best control of the disease or insect. Included with this answer is a fact sheet on history and controls for crabapple diseases and insects.

 Suggest taking some of the diseased leaves and the white substance on the trunk to a local nursery for identification.  There are at least two sites in the Denver area for diagnosing the exact attacking agent:  Jefferson County Fairgrounds has a CSU site and 888 Iliff is the Denver CSU site.

Probably impossible but If the hive could be moved away from the crabapple tree, the potential for harming bees during spraying treatments could be reduced.

Colorado Master Gardener, Denver County Replied August 06, 2019, 4:02 PM EDT

Loading ...