Key Takeaways:
Many Houston-area tree problems start in the soil, with compacted clay, poor drainage, and root damage leaving trees stressed and open to pests and disease.
Each local species has its own short list of likely problems, so the right fix depends on knowing what you're looking at before you treat anything.
Texas A&M Forest Service advises against pruning or wounding oaks from February through June to reduce the risk of oak wilt.
When a tree starts to look wrong, most people search for a disease name. A better first question is simpler: what kind of tree is it? A live oak, a loblolly pine, and a crape myrtle fail in completely different ways, and the fix for one can be useless for another.
The guide below works species by species through the trees we see most often across Pasadena, Deer Park, La Porte, Webster, and League City. For each one, you'll find the problems that show up most, what they look like, and what helps. When something doesn't fit, a professional tree inspection beats guessing.
Why Start With the Site Instead of the Bug?
Insects and fungi get the blame, but they often arrive second. Gulf Coast clay compacts under cars, foot traffic, and construction equipment, and compacted roots can't take in water or oxygen well. Add poor drainage, a buried root flare, or roots cut during a driveway job, and the tree runs on empty.
Texas A&M Forest Service lists saturated soil, fill dirt, soil compaction, root zone excavation, drought, and heat among the stresses that open the door to hypoxylon canker. The same stresses invite bark beetles, scale, and borers. Fix the site and many "pest problems" get easier to manage.
That's why our plant health care work starts below ground. Clearing a buried trunk flare through root collar excavation or relieving compaction often does more for a struggling tree than any spray.
What Goes Wrong With Live Oaks?
Live oaks are tough, long-lived, and the backbone of many Bay Area yards. Their most common troubles tie back to stress and wounds.
Hypoxylon Canker
The fungus lives quietly in many healthy trees and invades the sapwood once a tree is weakened. Early signs are a thinning crown and branch dieback. Later, bark sloughs off and exposes tan, olive, or reddish-brown powdery patches.
Texas A&M Forest Service is blunt about it: by the time those spores are visible, the tree is dead, and there is no known control other than keeping trees vigorous. Dead trees near a house or driveway should come down quickly, and the Forest Service warns that climbing them is dangerous.
Oak Wilt
Texas A&M Forest Service calls oak wilt one of the most destructive tree diseases in the country, with confirmed cases in 76 Texas counties and live oaks passing it to neighboring trees through their connected root systems. The Houston Area Urban Forestry Council says oak wilt is presently not a problem in the Houston area but warns outbreaks are possible, so prevention is the right posture here.
The Forest Service's advice is simple: avoid pruning or wounding oaks from February through June, and paint every oak wound immediately, any time of year. Live oaks with yellow and brown leaf veins deserve a closer look. Our oak wilt guide covers symptoms and treatment in depth.
Why Do Water Oaks and Laurel Oaks Fail?
Water oaks and laurel oaks grow fast, and they pay for it. They're shorter-lived than live oaks and prone to internal decay as they age, which leads to large limbs dropping without much warning. Texas A&M AgriLife Extension lists water oaks among the oaks most susceptible to hypoxylon canker.
The fix here is mostly about risk. Look for mushrooms or conks at the base, cavities, dead limbs high in the crown, and bark falling away in patches. A mature water oak with those signs near a home should be evaluated soon.
Sometimes careful pruning buys years. Sometimes tree removal is the safer call, and it's better made on a calm day than after a storm.
What Kills Pine Trees Around Houston?
Loblolly pines usually tell you they're in trouble through the needles. Fading, thinning, or browning needles after a drought or a lightning strike are a warning, since bark beetles target pines that are already stressed. Look for small pitch tubes or sawdust on the bark. Once beetles take hold, they can move to nearby pines, so a dead pine shouldn't stand around for months.
Fusiform rust is the other name you'll hear. It causes swollen galls on branches and trunks.
Texas A&M Forest Service reports rust incidence in East Texas loblolly pine holds at about 10 percent, compared with about 40 percent in slash pine. A gall on a branch can be pruned out. A gall on the main trunk weakens the tree at that point and is worth having checked. Confirmed beetle activity calls for targeted insect and disease management aimed at the pines at risk.
Why Are My Crape Myrtles Turning Black?
Black bark on a crape myrtle is usually sooty mold. That mold grows on honeydew, the sticky waste left by sap-feeding insects. Texas A&M AgriLife Extension describes crape myrtle bark scale as white or gray felt-like crusts on twigs and trunks that ooze a pink liquid when crushed, with heavy honeydew and black sooty mold following close behind. Aphids leave honeydew too.
Gray-white coating on leaves in spring or fall points to powdery mildew instead, according to AgriLife. Topping crape myrtles each winter doesn't help with either problem and leaves ugly knuckles behind. We covered treatment options in our guide to crape myrtle insects and diseases.
Why Are My Pecan Leaves Turning Yellow?
Yellow patches on pecan leaves in summer often trace back to aphids. Texas A&M AgriLife Extension notes the black pecan aphid injects a toxin that turns leaf tissue between the major veins bright yellow, and an average of only three per compound leaf can cause severe leaf damage and defoliation. The two yellow aphid species are far less harmful. Their populations often build in summer and then crash on their own.
Fall webworms are another common complaint. Their silk tents look alarming, but AgriLife says they don't harm established trees. A pecan that loses leaves early year after year is worth a diagnosis rather than another guess.
What Problems Hit Palms on the Gulf Coast?
Palms play by their own rules. UF/IFAS identifies potassium deficiency as the most common nutritional disorder of palms, showing up as yellow spotting and brown tips on the oldest fronds. Over-pruning and high-nitrogen lawn fertilizer make it worse.
The bigger worry is lethal bronzing, a fatal disease with no cure, according to the Texas Department of Agriculture. As of October 2026, TDA lists infested portions of Galveston County, including Kemah, under an active quarantine. A declining palm needs a real diagnosis, and specialized palm care starts with telling nutrient problems apart from disease.
When Does a Tree Problem Need a Professional?
Some problems are cosmetic. Others put people and roofs at risk. Call in an arborist when you see:
Cracks, cavities, or mushrooms at the trunk or root flare
Large dead limbs, especially over a house, driveway, or play area
A tree that has started leaning or lifted soil on one side
Sudden decline across a whole canopy in a single season
Diagnosis should come before treatment. Soil and tissue testing can separate a nutrient problem from a disease, and the early warning signs of tree disease help you know what to watch. For a broader rundown by disease, see our post on common tree diseases in Texas. If a tree can't be saved, choosing trees suited to Southeast Texas for the replacement prevents a repeat.
Get the Right Diagnosis for Your Trees
Most tree problems around Houston come back to one of two things: a stressed site or a species-specific pest. Knowing your tree narrows the list fast.
Catching a problem early keeps the fix simple. Waiting usually takes options off the table.
Monster Tree Service of Texas Gulf Coast diagnoses and treats trees in Pasadena, Deer Park, La Porte, Webster, Friendswood, League City, Kemah, and surrounding Gulf Coast communities. Call or text our team for a free estimate, with no obligation.