What to do with Trees Recovering from Winter Storm Uri 
by: Stephen J. O’Shea

It has been almost six months since winter storm Uri blanketed Texas in a week-long freeze and, despite ample rain, many Texas trees are still showing signs of stress. Tufts of leaves give some a patchy, inverted look – while others are losing vast amounts of bark, or seemingly dying overnight – leaving many Texas home and land owners wondering what they should do.

Texas A&M Forest Service and Neil Sperry, the Texas gardening and horticulture expert, joined forces this past spring to send a unified message across the state: wait. More specifically, Gretchen Riley, the Urban and Community Forestry Program Leader at Texas A&M Forest Service, asked Texans to wait until mid-July before cutting down leafless trees.

The good news is that the vast majority of trees that were late to leaf out have mostly, if not fully, recovered. Sickly or struggling trees are harder to come by, and time has lent a level of clarity as to the state and likelihood of survival for most struggling trees.

“The waiting was important, because we’re just now beginning to differentiate between those trees that are obviously not going to survive; those that are wounded and we hope will survive; and those that are definitely going to survive, but are going to take a little while to come back,” said Sperry, who has been studying the recovery of Texas trees for the past several months.

Now the time has come for Texans to make a decision: to remove their trees, or not to remove their trees.

THE SHORT ANSWER 

According to Riley, if your tree is bare and hasn’t put out a single leaf by now, it is almost certainly dead. Waiting a few more weeks, or even months, won’t change that. And unfortunately, this applies across the board: even to palm trees.

“Anything green means that the tree has a chance for recovery,” said Riley. “But a single small frond should have grown and opened on palm trees by now. No green means it is dead and has already started rotting internally.”

If this is the case for any of your trees, it is probably time to consider how and when to remove your tree. The short answer: when convenient, and with the help of a professional or certified arborist.

THE LONG ANSWER 

By this point, few trees are still completely bare. The more common scenarios that arborists and foresters are seeing across the state are trees with poor or patchy canopies. By this point in the summer, and with all the rain we’ve been receiving, healthy trees should already have a full canopy of leaves. The ones that don’t were clearly affected by the freeze, as detailed in our article from May.

This isn’t to say they won’t be healthy and happy come next spring. And there are a few ways to determine if your tree is in good shape, or if it could use a helping hand.

“Trees that have 50% or more of their normal canopy are likely to survive,” said Sperry, referring to hardwoods and established trees. “But if it’s a 20% or 30% canopy over the whole tree, then that tree has suffered a bad hit, and it may not have enough to come back.”

It can be hard to remember what a full canopy looked like for a previously healthy tree, and so Gretchen Riley has come up with another method for determining a tree’s state.

“Imagine a circle around all of your tree’s branches,” said Riley. “Twenty-five percent or more of that circle should be filled in with leaves. If not, that tree is most likely going to die, and it is worth planning to remove it. If more than 25% of that circle is filled with leaves, there is still a chance for full recovery.”

One way you can monitor your tree’s progress is by taking a photo of your tree’s canopy as soon as possible. Keep that photo—remembering the angle you took it from—and then wait for next spring. Once the tree has fully leafed out, take another photo from that same spot, and compare the pictures for improvements. If there is more foliage next spring, that means the tree is in recovery.

OTHER COMPLICATIONS 

Patchy foliage isn’t the only mark of a stressed or struggling tree. Many Texas landowners are finding deep, wide cracks in the trunks of their oak trees. According to Riley, these are an exaggerated manifestation of the more typical frost cracks or “radial shakes.”

“Frost cracks are caused by a tree’s inability to endure expansion and contraction of the bark and wood that results from the freezing of water inside of the tree,” said Riley.

Water expands when it freezes, and since trees are more than 50% water, trees that had started coming out of dormancy leading up to winter storm Uri were particularly vulnerable to frost cracks. As the water inside their trunk and branches froze, it expanded. But with their outer-layer and bark also frozen, the outside of the tree wasn’t able to expand with the inside – leading to ruptures in the trunk and bark.

Many of these cracks were only partially visible, if not invisible, following the winter storm. The recent surge of summer heat, however, has exacerbated those cracks, making them more visible in some trees.

“The good news is that trees have amazing, built-in mechanisms for recovering from trunk damage and frost cracks,” said Riley. “So trees with one or two cracks should be able to seal themselves with relative ease.”

On the flip side, bark is still essential for protection against pests and diseases. Trees with multiple cracks or lots of exposed wood are unlikely to recover, and trees with few but deep cracks should be monitored closely.

The few exceptions are lacebark elms, sycamores and crape myrtles. These are more likely to survive since, in most cases, the damage appears to be a shredding of the outermost layer of bark, sparing the wood itself. However, you should still watch closely for oozing discharge and other signs of stress, such as browning foliage or expanding cracks, leading up to next spring.

ROOT SHOOTS 

Surprisingly, a large number of trees, and a variety of species, are sprouting up shoots from the base of their trunks and root systems. While this might seem like a desperate attempt from the tree to stay alive, it’s actually a great way for landowners to grow and nurture a tree from a tiny sapling back to a fully grown adult. And it can mature much quicker than usual.

“The strong healthy root system present from your previous tree will help your new tree grow at a faster rate than newly transplanted seedlings,” said Riley. “This fall, select the best five or so sprouts and prune away the rest.  Let those five grow next year, and then select the most vigorous of those to be your new tree.”

You will still have to remove the old tree, but this method should save you the cost of grinding its stump, as well as buying and planting a new tree: which would likely grow at a slower rate than your root shoots, anyway. Crape myrtles, in particular, can grow back with astounding speed.

“You’re not going to lose a crape myrtle to cold. It might freeze to the ground, but it will come back,” said Sperry. “And if you have it trained as a tree—as is usually done with Tuscarora, Muskogee or Natchez crape myrtles—you can have a 20-ft crape myrtle grow back in two to three years.”

TREE PRUNING AND REMOVAL 

There are few decisions more difficult than when or how to remove a tree from your property. Trees have immense sentimental and monetary value. But their worth is rarely more than your roof, your house, or your life.

You can start by removing dead branches, or by pruning back the dead ends of branches on trees that experienced significant dieback. These branches are more likely to break off and injure property or people than the main body of the tree. It is still a dangerous and difficult task, though, and Texas A&M Forest Service—along with Neil Sperry and countless other industry experts—highly recommend enlisting the services of an I.S.A. certified arborist.

“When having major tree work done, you really need a specialist who knows how to do it safely,” said Sperry. “They will have the tools, and they will have the knowledge and experience to do it safely.”

TREE CARE AND TREE REPLACEMENT 

Once your trees have been pruned or removed, it’s essential to maintain a watchful eye. Our trees have been spoiled with an unusually wet spring and summer, but with August coming in hot and fast, Texas soils are bound to dry up quickly – and our trees don’t need anything that might put them over the edge.

“They’ve been stressed, and they don’t need any more stress,” said Courtney Blevins, a Staff Forester and subject matter expert at Texas A&M Forest Service. “So when we get into the heat of August, one thing you might want to do is give them deep, supplemental watering once or twice.”

Meanwhile, if you’re planning on replacing a tree that you’ve had removed, Sperry recommends that you don’t put the new tree right where you had the old one, unless you have the stump ground out when a professional comes to remove the dead tree.

MOVING FORWARD 

Winter Storm Uri was an unprecedented experience for much of Texas. Temperatures fell well below freezing, plaguing the state for almost an entire week – and it hit right after a heat wave triggered many of our state’s trees into leafing out early.

So don’t overthink which tree to plant next, or whether you should remove a tree before its time. Simply remove the ones that are dead or dying, take care of the trees that are still living as best you can, and look forward to next spring, when they will hopefully come back in full. 

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Contact:

Courtney Blevins, Staff Forester, Texas A&M Forest Service, cblevins@tfs.tamu.edu, (817) 531-3119

Gretchen Riley, Urban and Community Forestry Program Leader, Texas A&M Forest Service, griley@tfs.tamu.edu, (979) 458-6650

Stephen O’Shea, Communications Specialist, Texas A&M Forest Service, stephen.oshea@tfs.tamu.edu, (979) 458-6649