Recent below-freezing temperatures damaged some semi-evergreen plants, while others may only appear that way. It’s not a bad idea to wait for spring and see what leafs out and what doesn’t.
Residents of south central Texas have experienced the first deep freezes in years, with temperatures dropping to 19 degrees in recent weeks. Many homeowners welcomed the cold temperatures as an incentive to cut back bougainvilleas and other tropical perennials that had become extremely overgrown over the past few warm winters.
The freeze also damaged a few “semi-evergreens” — plants that normally don’t drop leaves for long (or only in certain conditions like drought or extreme cold). In San Antonio, this means species like striped agaves, some citrus and especially Mexican olive (Cordia boissieri) have taken a hit.
Although we all know that Mexican olive can suffer in cold weather (it’s not considered cold hardy in Austin!) we rarely have a chance to see it bare in San Antonio. In extreme cold, even the trunks may (or may not) experience damage. Trees with “south wall” protection — located just south of a warm sunlit winter wall that protects them from north winds — may get by with little damage at all.
When in doubt, just scrape off a fine sliver of bark and look for green tissue underneath. Start in the upper branches and move down toward the trunk. If you see green tissue under the bark, the branch is still alive; it may even have new leaf buds already present. If you reveal black or “slimy” tissue, mark it for later pruning. But don’t be too eager to cut Mexican olive back just yet! The roots of the tree are generally well protected against cold; it’s not a bad idea to wait for spring and see what leafs out and what doesn’t.