Red maple white spots on leaves 🍁🍁🍁

[dvsrk563]

This morning I noticed white spots on couple of leaves on my red maple, I didn't notice them yesterday when I watered. Is this something I need to be worried/treated before it gets worse.

Placement: Outdoor patio
Sunlight: Full sunlight from morning to noon.

 

[19Mateo83]

This morning I noticed white spots on couple of leaves on my red maple, I didn't notice them yesterday when I watered. Is this something I need to be worried/treated before it gets worse.

Placement: Outdoor patio
Sunlight: Full sunlight from morning to noon.

View attachment 428638

What time of day do you water?
Are you using any liquid fertilizer?
Can the spots be wiped off?

 

[dvsrk563]

What time of day do you water?
Are you using any liquid fertilizer?
Can the spots be wiped off?

usually I water in the afternoon (2pm to 5pm) after the shade comes and sun light goes away.

I’m using slow release fertilizer N-P-K with 19-6-12, they are used in fertilizer pods.

I could see same spot from underneath the leaf.

 

[19Mateo83]

usually I water in the afternoon (2pm to 5pm) after the shade comes and sun light goes away.

I’m using slow release fertilizer N-P-K with 19-6-12, they are used in fertilizer pods.

I could see same spot from underneath the leaf.

Ok, that rules out sun burn spots and fertilizer residue. It could be bug damage. The reason I asked is I have a purple JM and I have roughly the same sun light and water and with the same type of fertilizer and I noticed some spots like this on mine this morning. It’s only on a couple leaves like yours.

 

[dvsrk563]

Ok, thank you for sharing the details.

 

[sorce]

Japanese Maple – White Spots on Leaves | Walter Reeves: The Georgia Gardener

What are the "white spots" on your Japanese maple leaves? It’s a fungal disease called phyllosticta. Here's when it appears, and what to do about it.

www.walterreeves.com

Sorce

 

[dvsrk563]

Japanese Maple – White Spots on Leaves | Walter Reeves: The Georgia Gardener

What are the "white spots" on your Japanese maple leaves? It’s a fungal disease called phyllosticta. Here's when it appears, and what to do about it.

www.walterreeves.com

Sorce

Thank you for sharing, will watch to see if it is going to spread in my case and I will check if there is any cure for it.

 

[Dav4]

Ok, that rules out sun burn spots and fertilizer residue. It could be bug damage. The reason I asked is I have a purple JM and I have roughly the same sun light and water and with the same type of fertilizer and I noticed some spots like this on mine this morning. It’s only on a couple leaves like yours.

"Sun burn spots" due to watering in the sun is an old wive's tale... sorry, pet peeve of mine so I had to say something

 

[19Mateo83]

"Sun burn spots" due to watering in the sun is an old wive's tale... sorry, pet peeve of mine so I had to say something

Well then it definitely wasn’t that

 

[giventofly]

"Sun burn spots" due to watering in the sun is an old wive's tale... sorry, pet peeve of mine so I had to say something

Always heard this from my parents, never really believed it because never saw it happen. glad it isn't really true

 

[Orion_metalhead]

You have a Japanese maple, not Red Maple.

Water early in day. Watering as late as you are leaves the underwatered through the hottest parts of the day, possibly shocking the tree. They like morning and late day sun. I would give some sun protection from 11pm through 4pm if possible..

 

[rockm]

I'd agree this is a fungal thing.

As for the sunburn leaf spot myth, think about it. First off, the focal length for sunlight to focus through a water droplet to "burn" a leaf is to short (think focusing a magnifying glass on a leaf to burn it--lens has to be six or more inches away.) For the water to get so hot it boils the leaf--not enough volume and the water would simply evaporate before boiling... If water acted like a lens and got water that hot, woodlands across the planet would burst into flames...