Maple Tree Leaves

Question: It appears that some of my maple tree leaves are deteriorating.  The range of the leaves go from healthy  to a few white spots along the spines to a lot to dying. The backside of a small number of leaves have white bugs.  The leaves are almost completely dead on three lower branches of the tree.  We have two additional maple trees with one having a similar problem on a much smaller scale, no dead leaves. 

Thank you for helping me!!!

responder: Hania Oleszak  Replied June 27, 2023, 12:18 PM EDT
response: Hi Deb, 1. When did you first notice these symptoms, specifically the dieback of the lower branches? 2. How do you water the tree/how much water does the tree get? 3. Could you send a picture of the lower trunk, where it meets the soil line? I do see the insects, possibly leafhoppers or aphids, and the white spots likely associated with their feeding. However, I don't believe that the leaf/branch dieback is actually due to the insects.  Thanks! Hania

responder: The Question Asker Replied June 27, 2023, 12:48 PM EDT
response: Hello Hanna,I noticed the die back starting about a month ago.Due to all the rain I have just started watering on Sunday. Thank you,DebSent from my iPhone On Jun 27, 2023, at 10:18 AM, Ask Extension <<personal data hidden>> wrote:﻿

responder: Hania Oleszak  Replied June 27, 2023, 12:54 PM EDT
response: Hi Deb, Thank you. Prior to this season, what has been your watering technique (i.e., how do you water and how often/how much)? How long ago was the landscape fabric and the rocks put in? Thanks, Hania

responder: The Question Asker Replied June 27, 2023, 3:35 PM EDT
response: Hi Nanai,The tree is very close to the property line so on our side the tree gets watered 16 minutes twice a day three times a week. The Maple tree. fabric and rocks were part of the original landscaping that was done in 2006. Thanks!!!DebSent from my iPhone On Jun 27, 2023, at 10:54 AM, Ask Extension <<personal data hidden>> wrote:﻿

responder: Hania Oleszak  Replied June 27, 2023, 5:10 PM EDT
response: Hi Deb,  Based on the information you've provided me, I think that the source of the problem you're seeing in your maple is abiotic, likely water stress. This can contribute to lower limb dieback and can take many years to finally show symptoms.  Generally, mature trees should be watered deeply and infrequently. More specifically, you might aim to water your tree every two weeks or so, approximately 10 gallons per inch in diameter. So, if your maple is a foot in diameter, you'll want to apply about 120 gallons at a time every couple of weeks. Additionally, during really dry periods during fall and winter, you'll want to water your trees about once a month when temperatures are greater than 40F. Here is some more information on watering mature trees: https://cmg.extension.colostate.edu/Gardennotes/657.pdf. In addition to the light and frequent watering, the large rock mulch and landscape fabric are likely causing additional problems with water uptake, since they both contribute to soil compaction, can restrict root function, and cause overheating of the roots. If possible, I would recommend removing the landscape fabric and rock mulch surround the tree and apply an organic mulch instead (more info here: https://cmg.extension.colostate.edu/Gardennotes/658.pdf).  The insects are likely secondary to the initial abiotic stressors, likely just taking advantage of the tree's stressed state. Their damage shouldn't really affect the tree, but if you take a closer clear photo of the insects under the leaves, I can make management recommendations to help control them.  Hania

responder: The Question Asker Replied July 02, 2023, 10:03 PM EDT
response: Hello Hanna,Thank you for all of your help and information.  I really appreciate it. Take care,DebSent from my iPhone On Jun 27, 2023, at 4:41 PM, debra oppenheim <<personal data hidden>> wrote:﻿Sent from my iPhoneBegin forwarded message:From: Ask Extension <<personal data hidden>>Date: June 27, 2023 at 3:10:42 PM MDTTo: Deb Oppenheim <<personal data hidden>>Subject: Re: Maple Tree Leaves (#0107542)﻿