Hello,

The symptoms you’re describing—leaves turning yellow, then developing black spots and falling off—can be alarming, but they may not necessarily indicate a serious problem. According to Purdue University, premature yellowing and leaf drop observed on tulip trees (Liriodendron tulipifera), accompanied by circular black spots between the veins of the yellowing leaves, are symptoms most likely related to root stress. These symptoms, which are often mistaken for a fungal leaf spot disease, do not usually affect the long-term vigor or health of the tree. More information at this link:

Tulip Leaf Drop-No Cause For Alarm (purdue.edu)

The University of Florida also notes that leaf spots on tulip trees are usually not serious enough to warrant chemical controls. Once leaves are heavily infected, the opportunity for chemical control is lost, and the recommended action is to rake up and dispose of infected leaves. More information is at this link:

ENH-522/ST363: Liriodendron tulipifera: Tuliptree (ufl.edu)

Chlorine from pool water can potentially cause damage to plants if it is in high enough concentrations. However, it’s more common for the symptoms you’ve described to be associated with environmental stress or pathogens. If the chlorine levels were very high, you might see more widespread damage to the foliage, not just yellowing and black spots.

To address the issue, ensure that the tree is properly watered and mulched, and avoid piling mulch against the trunk. If the problem persists or worsens, it might be worth consulting with a local arborist or MSU Plant and Pest Diagnostics for a more precise diagnosis and treatment options. They can provide advice tailored to your specific situation and local conditions. Remember, healthy trees are more resilient to stress and potential pathogens.

OPTION 1:

For a confirm and precise identification of the problem, I recommend you send all your images by e-mail to the MSU Plant & Pest Diagnostics Lab. The experts there can also provide you with the best treatment options. Their email is <personal data hidden> - Please include your name – The lab will let you know if they need a sample sent. FYI – The lab may also ask for additional images too.

Their website is at this link:

Plant & Pest Diagnostics (msu.edu)

Their Contact Information is at this link:

Contact Us - Plant & Pest Diagnostics (msu.edu)

This link will explain the details on submitting a sample to MSU Plant & Pest Diagnostics Lab:

Submit Samples - Plant & Pest Diagnostics (msu.edu)

OPTION 2:

You can consult with a local arborist for a more detailed onsite assessment and personalized advice. To find an arborist in your Zip Code go to this link:

Find an Arborist (treesaregood.org)

I hope this helps!