why would maple tree leaves curl in one day and be brown the next

Asked August 18, 2016, 1:48 PM EDT

I had 2 maple trees planted in my yard by a nursery/landscape company about 2 years ago. The trees are about 15-18' tall and about 4" in diameter a foot above the ground. Last year I watered these trees frequently. Last year, the leave would brown around the edges if it was too dry but they would respond well to watering. This year, the trees have done well - no browning around the edges of the leaves. I monitor them closely and I've really only had to water them as part of watering the lawn (rarely have I done targeted deep watering). A week ago one of the trees had 98% of its leaves severely curl and dry in one day. The day before, the leaves looked fine. Upon seeing the curled leaves, I watered the tree heavily and we had a heavy rain that night. The next day, the leaves were brown. If I had cut off a limb and left it on the ground, I don't think the leaves would have browned that quickly. There is no damage to the truck of the tree, no insects or scale or any sign of an issue that would have caused this. The other tree still looks great. Other than the leaves being brown on the one tree, the two trees look the same.

What would cause the tree to do this so quickly? It has been dry this year but the curling and browning of the leaves is a completely different symptom than the browning of the edges of the leaves I observed last year when the tree apparently needed water.

I didn't think anything about it until I mentioned this to my father and he immediately brought up the lawn service that does the weed and feed on my lawn. They were there the day before the leaves curled. They applied weed control to the entire yard (not sure why since there were very few weeds in the lawn) but no fertilizer. The weed control contained 2,4-D, Mecoprop-p, and Dicamba. I wouldn't think a herbicide would affect a tree like that so maybe it is just a coincidence.

Any thoughts on what caused this? Do you think my tree will survive? I'm hoping the leaves just died but the tree will come out next spring.

Midland County Michigan trees and shrubs

5 Responses

The leaves curled and turned brown from not enough water in the root area. Even though you have two maples, they are not twins or clones. One may have a smaller root system or some defect below ground that is exacerbating the problem.

Not knowing how much rain your area received, it is possible that a few deep watering events were not enough. A lawn irrigation system is useless when conditions are dry... under one inch of water per week falling out of the sky. If the lawn irrigation system is set up correctly, it only puts down enough water in a week to dampen the top 2-3 inches of soil. Most of your tree roots are in the top 18-24 inches of soil. So it is possible that there was not enough water or not often enough or deep enough.

The leaves on the tree were probably a lighter green before they curled and turned brown. By the time they were curling, they were dead and dry. Brown is just the end and brown leaves never come back to life. If the leaves were a lighter green, they could have been dead then.

If you think it was the lawn company, then all your trees would be doing exactly the same. Most companies divide applications into small amounts because they are charging you by the visit, not the gallons or pounds applied.

With new trees, you need to water them for several years. They do not develop a big enough root system in one year to handle life in general. Some trees adapt more rapidly than others. Purchase a rain gauge. Any time we have under one inch of water a week (that's to one inch of soil below) you need to make that up. If you can dig in the soil and cannot find any damp soil in the top 4-6 inches of soil, the tree is dry.

Trees should be mulched and not have grass around them... but no mulch piled on trunks. There needs to be three inches deep of mulch that comes out farther than the ball when it was put in. You are trying to keep the soil cool and damp to enable root growth to go beyond the ball.

Do not fertilize the tree. You could finish it off. Check on moisture and mulch both trees. Right now, trees are making buds for next spring but if there is insufficient water, the tree is not going to fare well. This may just be the weaker of the two maples.

Brown edges or margins on leaves are fried. This means there was not enough moisture getting into the tree. Whether it was lack of available water or a compromised root system or a combination, it does not matter. Maples have many roots very close to the soil surface and if there is a lack of water, they are going to know about it immediately.

This is based on whether the trees were planted correctly... not above or below grade. You should be able to find big roots in the top one or possibly two inches of soil at the trunk. no deeper. If not, planting may be a problem. If there is burlap seen on the soil surface from the ball, that's a big problem, too.

Thank you, Gretchen.

Both trees were given a deep watering. It sounds like there is still hope for the one tree. I will not fertilize it. I will put mulch around both trees but not up the trunks.

I do know that the soil conditions where the two trees are planted are different. The tree with brown leaves is planted in black dirt that extends well below the bottom of the root ball when it was planted. The grade slopes down on one side and is level on the other side. The tree with the green leaves is planted in about 8-12" of black dirt with sand below that for several feet. This tree is planted on a slope with the slope falling off faster on one side. It was this tree that required more watering last year and that's also why I was surprised to see an issue with the other tree. Perhaps it is harder for the water to soak down as fast into the black dirt.

The leaves were definitely not any lighter green than normal the day before they curled and dried. I mowed my lawn the day before and the tree looked fine. The weekend before this happened, I was admiring both trees from a distance and thinking that they were really doing well this year. How quickly that changed.

Burlap is just visible at grade right at the trunk of the tree. No burlap is visible on the surface of the ground away from the trunk.

If the soil is different, this could mean the one planted in the black soil that is deeper is holding too much water. Sand below improves drainage. Black soil below means drainage is much slower.

I had an ISA certified arborist look at the tree. His assessment was that the leaves curled and turned brown due to a herbicide and not due to lack of water. He said the appearance of the leaves was indicative of this. He said the tree is not dead but weakened and may leaf out next year or possibly miss a year and leaf out the following year. This was based on the branches being supple, not dry and brittle. He will be back to check on the tree over the next 2 months and depending on what he finds he may recommend fertilizing the tree and would recommend wrapping the trunk of the tree up to the first branches over the winter.

If there not other trees damaged in the same area, I find it hard to believe only one would be affected. Good luck.