If you’re new to owning trees, here’s something no one warns you about: Central Texas summers are tough on them. By May, afternoons are already hitting the 90s. By July, stretches of 100°F days are completely normal. And if your trees aren’t prepared, the heat can do real damage fast.
The good news? You don’t need to be a tree expert to protect them.If you follow a few simple steps now, you can prevent most heat damage.
This guide breaks everything down in simple language so that even if this is your first summer with trees in your yard, you’ll know exactly what steps to take.
What Is Heat Stress in Trees?
Think of heat stress in trees like this: your tree drinks water through its roots and releases that water through its leaves, kind of like sweating. On a hot Texas summer day, your tree loses water through its leaves much faster than its roots can pull new water up from the soil. When that gap gets too big, the tree starts to struggle.
This is called heat stress, and it can cause leaves to turn brown, drop early, or curl up. In serious cases, it can cause branches to die or the tree to go into survival mode, where it stops growing and just tries to stay alive.
Trees that were planted recently (within the last one to three years) are the most at risk because their roots are still young and shallow. But even older, established trees can suffer during a long stretch of extreme heat if they are not getting the right care.
The great news is that heat stress is mostly preventable. And May is the perfect time to act, before the worst of the heat arrives.
Signs of Heat Stress in Trees: What to Watch For
Before we get into the prevention steps, it helps to know what the signs of heat stress in trees actually look like. Walk around your yard once a week this summer and keep an eye out for these warning signs.
Tree leaves curling in heat is one of the first things you will notice. If the edges of your leaves are rolling or curling inward, your tree is trying to protect itself by reducing how much leaf surface is exposed to the sun. This is one of the earliest and most reliable signs of heat stress in trees, and it should not be ignored.
Brown, crispy leaf edges are called leaf scorch. The brown edges are dead leaf tissue. Tree leaf scorch treatment is not about fixing the brown leaves (those will not recover), but about fixing the conditions causing the problem in the first place.
Leaves falling off in summer means the tree is shedding them on purpose to reduce how much water it needs to survive. It is a stress response.
Leaves that look wilted or droopy, even after watering, means the tree’s water system is having trouble keeping up with the heat.
Not sure if your tree is already stressed? Send us a photo or call (210) 202-4284—we’ll tell you what’s going on before it gets worse.
How to Protect Trees from Heat: Your Step-by-Step Summer Checklist
Knowing how to protect trees from heat before the worst of summer arrives is the difference between trees that thrive and trees that barely survive. Here is exactly what to do.
Step 1: Put Mulch Around Your Trees
If you only do one thing on this list, make it this one.
Mulch keeps the soil from drying out too fast, keeps roots cooler, blocks weeds from stealing water, and improves the soil over time. Bare soil in direct Texas sunlight can reach temperatures above 130°F at the surface. The roots of your tree are living just below that. Mulch acts as a barrier between that heat and your tree’s roots.
How to mulch the right way:
- Add fresh mulch every summer as it breaks down.
- Use wood chip mulch such as shredded hardwood, cedar, or pine bark. Avoid rock or gravel because they absorb heat and make things worse.
- Spread a 3 to 4 inch thick layer around the base of your tree.
- Leave a 2 to 3 inch gap between the mulch and the trunk. Mulch touching the trunk can cause rot.
- Spread the mulch out as far as the canopy reaches.
Step 2: Water Deeply, Not a Little Bit Every Day
This is where a lot of first-time tree owners go wrong, and it is an easy mistake to make. Watering wrong is the #1 reason trees fail in summer.
You might think watering every day is good for your tree. But watering a small amount daily actually causes the roots to grow close to the surface, where the soil dries out the fastest during summer heat.
What trees actually need is deep, less frequent watering. This trains the roots to grow down into deeper soil where it stays cooler and holds moisture longer.
How to water trees in extreme heat:
- Avoid watering in the afternoon. Most of it will evaporate before reaching the roots.
- Water newly planted trees (in the ground less than 2 years) 2 to 3 times per week.
- Water established trees (3 or more years in the ground) once or twice per week.
- Water slowly for 30 to 60 minutes per session using a soaker hose at the drip line, which is the outer edge of the canopy.
- Always water before 8 AM. Morning watering reduces evaporation and gives roots time to absorb moisture before the heat peaks.
Quick soil test: Push a screwdriver into the soil near the outer edge of the canopy. If it slides in and comes out damp, you are in good shape. If it is hard to push in and comes out dry, your tree needs more water.
Not sure if you are watering correctly for your specific trees? Stop by our nursery or send us a message and we will walk you through it.
Step 3: Do Not Prune Your Trees in the Summer
Pruning during a heat wave removes the leaves your tree depends on to make energy, and makes things harder, not easier. The best times to prune in Central Texas are late fall and late winter to early spring.
During summer, the only pruning that is okay is removing clearly dead or broken branches. Everything else should wait.
Step 4: Give Newly Planted Trees a Little Extra Shade
If you planted a tree within the last 18 months, its roots are still small and shallow. A temporary shade cloth rated at 30 to 40 percent on the southwest side of the tree can reduce how much heat the leaves absorb during the hottest part of the day.
Take it down by fall so your tree adjusts to full sun on its own.
Step 5: Stop Fertilizing Once It Gets Hot
Fertilizer encourages new growth, and new growth needs a lot of water and energy to support. Stop fertilizing by late June and do not start again until September or October. If you want to fertilize this year, do it now in May before the heat builds.
Step 6: Check If Your Soil Is Too Hard
Compacted soil blocks water from soaking in and stops roots from spreading. Signs include water pooling on the surface instead of absorbing, the ground feeling very hard underfoot, or a tree that looks stressed even when you water regularly.
Mulching consistently and aerating the soil each spring gradually improves things. If compaction is severe, it is worth getting a professional opinion before summer peaks.
Not sure what is going on with your soil or your trees? We are happy to take a look. Request a visit or quote here.
What to Do If Your Tree Is Already Showing Heat Stress
If your tree is already showing signs of heat stress — curling leaves, brown edges, or early leaf drop — here is what to do. Knowing how to protect trees from heat at this stage is just as important as prevention.
First, do not rush to water more than normal. Overwatering causes root rot. Do the screwdriver soil test first to check if the soil is actually dry.
Apply mulch right away if you do not have it in place.
Look for anything else adding stress. A hot nearby wall, weeds at the base, or crowded roots can all make things worse.
Expect some leaves to stay damaged. Scorched leaves will not turn green again. But healthy new growth next spring means the tree made it through.
When in doubt, call for help. Catching a problem early is always easier and less expensive than waiting.
If you are worried about a tree, do not guess. Call us at (210) 202-4284 and we will help you figure out what it needs.
Quick-Reference Checklist: Summer Tree Care in Texas
Save this and check it off before June arrives:
- Add 3 to 4 inches of wood chip mulch around all trees, extending out to the drip line
- Switch to deep, less frequent watering (2 to 3 times per week for new trees, 1 to 2 times for established trees)
- Water only in the early morning before 8 AM
- Stop all heavy pruning until fall or late winter
- Check if your soil is compacted and aerate if needed
- Stop fertilizing by late June and resume in fall
- Set up temporary shade cloth on any tree planted in the last 18 months
- Take a weekly walk around your yard and look for curling leaves, brown edges, or wilting
The Bottom Line
Summer tree care in Texas is not complicated, but it does require acting before the heat peaks — not after. Start with mulch, water deeply and less often, follow the right steps for how to water trees in extreme heat, and keep an eye out for signs of heat stress in trees like curling leaves or brown edges. If your trees are newly planted, give them a little extra attention this season. Most heat stress in trees is preventable, and the steps that prevent it are simple. You do not need to be a tree expert. You just need to act before the heat peaks, and May is exactly the right time to do it. A little effort now means healthier, stronger trees all summer long and for many years to come.
We Are Here to Help
For nearly 50 years, Alfaro Tree Sales has helped Central Texas homeowners choose, plant, and protect trees that actually survive our climate. Whether you have questions about a tree that is not looking right, just put something new in the ground this spring, or you want someone to walk you through what your yard needs before summer hits, our team is happy to help.
No question is too basic. We love helping first-timers get it right from the start.
Come visit us in Atascosa, just south of San Antonio off Highway 16, and talk with our team in person. Or give us a call and we will point you in the right direction.
FAQs
No. Fertilizer pushes new growth, and new growth needs a lot of water and energy to support. During a heat wave, your tree is already working hard just to stay stable. Adding fertilizer makes things harder. Wait until temperatures cool back down.
The two best windows are early spring (March through April) and early fall (September through October). Both avoid the extreme summer heat that makes fertilizing risky and less effective.
Yes. When soil is hot and dry, fertilizer can concentrate in the root zone without enough moisture to dilute it, which can damage roots and make heat stress worse. Summer is not the right time to fertilize, no matter the product.
Not right away. Newly planted trees need their energy focused on growing roots, not new shoots and leaves. Wait at least one full growing season before fertilizing, then start light with a slow-release fertilizer in early spring.
For most homeowners, compost or a slow-release granular fertilizer is the best starting point. Compost is the gentlest option and very hard to overdo. Granular works well but needs to be watered in properly. Spikes are convenient but deliver nutrients unevenly across the root zone.
