Leaves on a tree can turn brown for several reasons, including dry weather, heat, root damage, disease, insect activity or simply the normal change of seasons. Browning on its own doesn’t tell you the cause, so it helps to look at when it happened, which parts of the tree are affected and whether the tree has other symptoms.
Sometimes brown leaves are a short-term reaction that the tree recovers from. Other times, they may indicate a bigger problem that’s worth a closer look.
Normal Causes of Brown Leaves
In fall, many trees drop brown leaves as part of their normal cycle. Some trees also shed a few older, inner leaves during the growing season, which is usually nothing to worry about.
During hot, dry spells, trees may brown at the leaf edges as they lose water faster than roots can take it up. This is often called leaf scorch. The tree may look rough for a while but put out healthy leaves the following spring.
Possible Signs of a Bigger Problem
Browning that shows up suddenly in the middle of the growing season, affects one side or section of the tree, or keeps getting worse over several weeks may deserve closer attention.
Other symptoms that appear alongside browning can also be important. These include wilting, early leaf drop, dead branches, thinning in the canopy, oozing from the bark, cracks in the trunk or fungal growth near the base. Each of these can have several possible causes.
Root problems can also show up in the leaves. Construction, trenching, soil compaction or changes in drainage can damage roots, and the canopy may react later with browning or dieback.
Why a Single Symptom Isn’t Enough
Brown leaves can look very similar whether the cause is drought, root damage, disease or pests. That’s why it’s hard to tell what’s going on from the leaves alone.
Some serious problems do exist in Missouri. The Missouri Department of Conservation, for example, describes oak wilt as a disease that can kill red oaks within a year. But brown leaves on an oak don’t automatically mean oak wilt, and only a proper assessment can confirm a cause.
What You Can Do
Note when the browning started, which parts of the tree are affected and whether it’s spreading. Photos taken a week or two apart can help show changes over time.
During dry periods, deep, slow watering over the root area may help a stressed tree. Avoid heavy fertilizing or other treatments until you know what the problem is.
A tree health assessment can look at the tree as a whole, including the canopy, trunk and root area, to help narrow down possible causes and next steps. If branches have already died, deadwood removal can take them out before they fall.
Noticing brown leaves on a tree in your Joplin yard and not sure what’s behind it? Having the tree looked at can help you understand what may be happening and whether any action is needed.
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