Blue spruce disease and aspen trees

Question: Our blue spruce has lower branches that are dying. We need to know if it's a disease, drought, mites, etc.  Very upsetting, it's young and beautiful!  What can we do?
Also our aspen trees always get brown spots on their leaves.  We use tree insecticide that you mix in water and pour at the trunks, but it doesn't help.
Thank you so much.

responder: Weld County Colorado Master Gardeners Replied July 13, 2023, 10:38 AM EDT
response: Linda,  Thanks for your questions.   ASPEN: It appears your trees have Aspen Leaf Spot. This is caused by fungi that have infected the leaves. A wet spring like the one we have had is perfect for this condition.  Here is a fact sheet that describes the issue and treatment.   https://planttalk.colostate.edu/topics/insects-diseases/1403-aspen-leaf-spot/#:~:text=One%20of%20those%20problems%20is,disease%20to%20develop%20and%20spread.  It is important to rake up and throw away all of the infected leaves in the fall so the spores that overwinter in the old leaves don't infect the tree again next year.   Treatment is to spray infected leaves with a fungicide - see suggested products in the fact sheet below and follow all instructions on the label. As you describe this as a yearly event and the tree looks large, you may want to consider having a tree service come and do a series of spray next spring. First treatment is done at bud break in the spring and followed by repeat treatment as specific intervals.   https://planttalk.colostate.edu/topics/insects-diseases/1403-aspen-leaf-spot/  SPRUCE: I have sent your picture to one of our CMGs who is a tree expert. When I get her response I will send it to you.  Thank you for your patience on this topic.  Please let us know if  you have any other questions.  Ruth, Weld County CMG

responder: The Question Asker Replied July 13, 2023, 5:07 PM EDT
response: Thank you so much!  I will probably get a tree service.  I do have another question.  I have tomato plants that also develop yellow leaves that dry out, but the tomatoes are growing and appear healthy.  Any ideas?  I grew the same tomatoes last summer and didn't get yellow leaves.  Linda BolligOn Thu, Jul 13, 2023 at 8:38 AM Ask Extension <<personal data hidden>> wrote:

responder: Weld County Colorado Master Gardeners Replied July 14, 2023, 10:09 PM EDT
response: Linda,  Thank you for your patience.   SPRUCE: Our tree expert feels your blue spruce may be suffering from cytospora canker. This fact sheet from CSU describes the disease:  https://extension.colostate.edu/topic-areas/yard-garden/cytospora-canker-2-937/#:~:text=Cytospora%20species%20cause%20branch%20dieback,discolored%20areas%20in%20the%20bark.  From the fact sheet: drought and oxygen starvation of roots by flooding soil with water are the two most common stresses that predispose trees to Cytospora infection. We have experienced drought and then have been flooded with rain during a very wet spring. Make sure you are not now overwatering the tree.  Inspect the bark where the damaged branch goes in for canker and oozing (as described in the fact sheet) which may or may not be present. Please read and follow the section on how to remove the damaged branches and damaged bark where they join the trunk to get the bark to air out in the area of infection. This is control not cure.  TOMATOES: I have attached a fact sheet on the disorders of tomatoes that may help you identify what is causing the yellow leaves. There are many situations that can cause this condition: https://extension.colostate.edu/topic-areas/yard-garden/recognizing-tomato-problems-2-949/  Hope this helps. Let us know if you have any other questions.  Ruth, CMG

responder: The Question Asker Replied July 19, 2023, 12:25 AM EDT
response: Hello, Can someone diagnose these yellow spots on my lawn?  Some of them are like this with a "ring" and some are just spots.  Thank you,<personal data hidden>On Mon, Jul 10, 2023 at 10:36 AM Ask Extension <<personal data hidden>> wrote:  Dear Linda, Thank you for using Ask Extension. A request for support has been created and a representative will follow-up with you as soon as possible. Questions are usually answered within two business days. You can view this question's progress online. YOUR QUESTION #0109817: Blue spruce disease and aspen trees Our blue spruce has lower branches that are dying. We need to know if it's a disease, drought, mites, etc. Very upsetting, it's young and beautiful! What can we do? Also our aspen trees always get brown spots on their leaves. We use tree insecticide that you mix in water and pour at the trunks, but it doesn't help. Thank you so much. Ask Extension offers one-to-one expert answers from Cooperative Extension/University staff and volunteers within participating Land-Grant institutions across the United States. If you wish to provide additional comments or information regarding the issue, please login to your account for a complete archive of your prior questions and answers.  This message for informational purposes only. It is not intended to be a substitute for personalized professional advice. For specific local information, contact your local county Cooperative Extension office or other qualified professionals. eXtension Foundation does not recommend or endorse any specific tests, professional services, products, procedures, opinions, or other information that may be mentioned. Reliance on any information provided by eXtension Foundation, employees, suppliers, member universities, or other third parties through eXtension is solely at the user's own risk. All eXtension content and communication is subject to the Terms of Use which may be revised at any time.

responder: Weld County Colorado Master Gardeners Replied July 19, 2023, 9:22 AM EDT
response: Hi, this is Steve and I am covering Ask Extension questions this week. From the picture, I feel your lawn issue is Necrotic Ring Spot and will attach information concerning diagnosis of this and management. It is difficult to diagnose lawn issues from pictures and there are a number of diseases which can cause a lawn to look this way. If you could send more pictures - broader look at the entire lawn, close up of the affected area - that could be helpful. Here is the fact sheet: https://extension.colostate.edu/topic-areas/yard-garden/necrotic-ring-spot-of-kentucky-bluegrass-2-900/ If you have other questions, please don't hesitate to contact us again.