This looks like leaf scorch. While it can be caused by several issues, the most likely is lack of water reaching the roots during our recent hot, dry spell.
Proper watering by saturating the soil to a depth of six inches is especially important. Water once every one to two weeks during dry periods. A general guide for trees is 10 gallons of water per 1 inch diameter of trunk, per week including rainfall.
It is good that there are viable leaf buds beginning to grow, probably an indicator that the tree has received water recently. When rain stops, continue to give water. Mulch around the roots no deeper than 3-4 inches of shredded or chipped wood. Do not let mulch touch the trunk- keep it pulled away 4-6 inches.
Here is a detailed discussion of leaf scorch. Look through this to see if any other issues were at work around this tree, such as an application of too much fertilizer, compacted roots, etc.
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