Answer: It sounds like a water related problem. Overly saturated soils can cause the tip dieback you describe, even for swamp oaks. It can also affect the leaf margins of mature leaves. A 4 year old tree should certainly be established and should be able to adapt to soil conditions so you'll have to think back to see if you remember anything changing in the drainage or your watering practices. You can also take a few samples of the affected plant parts to your local cooperative extension or Master Gardener clinic for positive identification of the problem and steps you can take to improve the health of your oak tree.
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