Japanese Maple Leaf Issue

Question: I’ve been noticing these issues on my Japanese Maple leaves for a while now and not sure if it’s due to warmer temperatures and/or lack of water or a disease like powdery mildew.

responder: Answered by the Home and Garden Information Center (HGIC), University of Maryland Extension. For timely gardening information and tips, subscribe to our Maryland Grows blog and quarterly newsletter. Follow us on Facebook, Instagram, and YouTube. Replied September 16, 2024, 10:33 AM EDT
response: Hi,  This is typical on lave leaf plants at the end of the summer, especially with the high heat and drought conditions we had this past season.  Did you supplement irrigation this summer? If not, it would be a good idea to water periodically this fall to help it into winter. We are supposed to get some rain this week, but it has been a pretty dry month so far. You could give it a good soak today by laying a garden hose on a slow trickle at the base for about 20 minutes.  You can review out Watering Trees and Shrubs page for further guidance.  The leaves will fall off this autumn and should be fine next spring.  Emily

responder: The Question Asker Replied September 16, 2024, 10:40 AM EDT
response: I have irrigation for my yard, but I’m sure I probably could’ve watered my tree a lot more than I have. Do those type of trees require a lot of water? I wasn’t sure if I only need to use a water pitcher to be enough or if normally it needs a good hose soaking like you mentioned. ----------------------------------- Jason

responder: Answered by the Home and Garden Information Center (HGIC), University of Maryland Extension. For timely gardening information and tips, subscribe to our Maryland Grows blog and quarterly newsletter. Follow us on Facebook, Instagram, and YouTube. Replied September 16, 2024, 11:18 AM EDT
response: They are on the higher water requirement end but also just the LACE (sorry for the previous typo) leaf is delicate in full sun and the dark leaves soak up more heat. Are you feeling the soil after the lawn irrigation to see if its wet around the maple? It needs to be moist about 6 inches down to sufficiently reach the root area. If the irrigation is only running in the lawn for about 15 min. twice a week then it would not be enough. Are they spray heads? Is it reaching the tree? Are you doing it by hand or with a sprinkler? If you use a watering can or bucket, how much are you giving it?

responder: The Question Asker Replied September 16, 2024, 11:28 AM EDT
response: Well irrigation only is for the lawn (don’t have anything in flower bed yet aside from my tree - trying to figure what to plant). And sometimes I’ll use hose and other a watering can when I have extra from watering parts of grass I seeded. With hose I’m not sure how deep it’s getting. Might only water it from 30 seconds to maybe a minute max?-----------------------------------Jason   On Mon, Sep 16, 2024 at 11:18 AM Ask Extension <<personal data hidden>> wrote:

responder: Answered by the Home and Garden Information Center (HGIC), University of Maryland Extension. For timely gardening information and tips, subscribe to our Maryland Grows blog and quarterly newsletter. Follow us on Facebook, Instagram, and YouTube. Replied September 16, 2024, 12:07 PM EDT
response: Yes that probably wasn't enough time then. Just feel the soil under the mulch about 6 inches down. You can use a screw driver or garden stake to be able to get through hard soils.

responder: The Question Asker Replied September 16, 2024, 12:15 PM EDT
response: So depending on depth just let a hose saturate from 15-20 mins?  On Mon, Sep 16, 2024 at 12:07 PM Ask Extension <<personal data hidden>> wrote:

responder: Answered by the Home and Garden Information Center (HGIC), University of Maryland Extension. For timely gardening information and tips, subscribe to our Maryland Grows blog and quarterly newsletter. Follow us on Facebook, Instagram, and YouTube. Replied September 16, 2024, 1:09 PM EDT
response: That should be sufficient. You can check the soil after that time and see if it has soaked down enough then. The link for the Watering Trees and Shrubs page should can help explain more. Established trees need about 1 inch of water a week to not be drought stressed.