Q: The leaves of our Bottlebrush Buckeye are dying from the outer end back toward the stem. The line that separates the live part of the leaves from the dead part is straight and well defined, and it progresses over time from the outer end to about halfway back to the stem. The tree was planted in the spring of 1998 and it has done this the last two growing seasons. The plant gets full sun and is watered and fertilized regularly.

A: When the leaves on a plant die from the tip back to the stem or from the edges towards the mid-vein, I think “Water Stress”. I’ve seen this plant grown successfully in full sun but it always seems happier in dappled shade or a spot that gets some afternoon shadows. If your problem were a fungus or bacteria, the damage would be in the form of a spot. Edge- or tip-death means water hasn’t been able to travel to the margin of the leaf from the veins.

The problem could be caused by a root system that is still not large enough to supply all of the water the plant needs. You did excavate a BIG, WIDE hole when you planted it didn’t you? If your soil is hard clay, the roots could yet be struggling to grow through it and unable to find the moisture they need.

Your regular fertilizing could have forced the plant to grow more leaves than the roots could support in hot, dry weather. Stop fertilizing now and begin giving the plant ten gallons of water once per week. With a little luck, it should gradually recover.