Ask Mr. Smarty Plants

There are a couple of things that could be causing the problem in your Taxodium mucronatum (Montezuma bald cypress). One is that you are located somewhat north of what is considered the normal range for that particular species. According to this USDA Plant Profile, the natural habitat of this tree is a few counties in the southernmost tip of Texas and northern Mexico. However, we don't think this is fatal; often the USDA Plant Profiles are somewhat out of date, and plants will migrate or be cultivated out of the original range. It could mean, though, that the tree will be a little bit slower to develop. The more likely cause of the dieback on the upper reaches of the tree is transplant shock. You didn't say when you transplanted it into your garden, or how long ago. Woody plants, especially trees, should be transplanted in the winter in this part of the country, when they are semi-dormant and most of the fluids in the tree are down near the roots. Also, once a woody plant has been transplanted, it should be watered by sticking a hose down in the dirt around the roots and letting it trickle slowly until the water appears on the surface. This should be done every other day for the first few weeks, and longer if the tree was transplanted in hotter weather.

Our suggestion on this tree is watchful waiting. You might trim off the upper trunk if you feel the wood is actually dead there. Scratch the bark a little bit, if it's green underneath, the trunk is alive, it's just resting. Keep it well watered, and hope that it will recover from the roots up. Here is a U.S. Forest Service website that will give you more information on the amount of moisture the tree needs, and what its prospects are.

Taxodium mucronatum

Taxodium mucronatum

Taxodium mucronatum