Most sick trees give you warning. This one does not. A tree looks fine in June, wilts in a few hot days in July, and is dead with its leaves still hanging on it. Homeowners water harder. It does not matter. The problem is underground, and it has a name old Texas cotton farmers knew well: cotton root rot.
What it is, in plain terms
Cotton root rot is a soil fungus, Phymatotrichopsis omnivora, that lives deep in alkaline ground across Texas and the Southwest. It is not imported and it is not new. It sat in this soil long before the subdivisions did. It can host on more than 2,000 kinds of broadleaf plants, which is why it turns up in yards, orchards, and fields alike. It likes exactly what Collin County has: clay soil with a pH above 7, limestone underneath, and ground that gets hot in summer.
The fungus sits quiet in the soil until roots grow near it and summer heat arrives. Then it moves into the roots and rots them. A tree with rotted roots cannot drink, no matter how wet the yard is. That is why the hose does nothing. The wilt is not thirst. It is a cut supply line. Our tree diagnosis guide shows where root trouble sits in the full check, crown to base.
The signs, and how fast they move
Timing is the first clue. Cotton root rot kills in the heat, roughly June through September, when the soil is warmest. A healthy looking tree wilts over two to five days. Leaves turn dull, then a straw or bronze color, and they stay attached. A drought stressed tree drops its leaves. A root rot tree dies wearing them.
The pattern is the second clue. Death often spreads in a rough circle. One tree goes, then the shrub next to it, then the tree on the other side, as the fungus works outward through the soil. After summer rain, flat tan mats of spores sometimes show on the soil surface near a dead plant. They last a day or two and mean little by themselves, but with a sudden wilt they support the call. Down at the base, bark slips off roots that feel soft, and tan threadlike strands may show on the root surface. Compare that with the slower base decay in our piece on mushrooms at the base of a tree. That one creeps. This one sprints.
Who gets it around here
Fruit trees are the classic North Texas loss. Apple, peach, and pear trees can die in their first hot summers or after years of good crops. Our fruit tree guide already warns about short orchard life here, and this fungus is a big part of it. Shade and ornamental trees are not exempt. Redbuds, crape myrtles, and many broadleaf shrubs can go the same way, and pecans in a known patch deserve a close watch, since pecan care already runs long in this soil: see our pecan care guide.
Two groups mostly escape it. Grasses are not hosts, which is why a dead tree circle in a lawn fills in with turf like nothing happened. Junipers and cedars rarely get it either. That short list matters when it is time to replant, and it is most of the good news this topic has.
What does not work
There is no cure for a tree that has wilted from cotton root rot. Fungicide sprays do not reach a fungus that lives feet down in clay. Soil treatments sold as cures do not hold up in home yards. Extra water makes the homeowner feel busy and changes nothing, because the roots that would take it up are gone. Fertilizer is worse than useless. Do not pay for a treatment plan that promises to save a wilted tree from this. That money belongs on removal and a smarter replacement.
Old farm advice about digging deep sulfur pits and barriers exists for orchards, where the math is different. In a home yard in Melissa, McKinney, or Anna, it is not practical, and it does not sterilize the patch. The fungus survives in the ground for years on old root pieces. Plan around it, not against it.
What to do when a tree dies fast in summer
First, confirm it is dead, not dormant. Scratch twigs up and down the tree. Brown and dry all the way to the trunk means gone. Our guide to a dead tree or a dormant one walks through the check. A root rot tree over a roof, fence, or driveway then becomes a removal job before it gets brittle and harder to take apart. Our tree removal page covers how that work goes.
Second, mark the circle. Note which plants died and in what order, and take photos. That map is the record of where the fungus is active. Keep it with the house paperwork. The next planting decision in that part of the yard should start with it.
Third, replant with your head, not your heart. Do not drop another peach, apple, or redbud into the same hole and hope. Pick a resistant replacement or a juniper screen for that spot, or plant a new shade tree well outside the dead circle with the flare at grade. If a big part of the yard has gone in circles over several summers, get the soil and the pattern checked before you buy anything. Texas A and M AgriLife keeps the current resistant plant lists, and a ten minute check there beats rebuying the same loss. For yards around Melissa, a fast summer death with the leaves still on is reason enough to call before the next tree in the circle goes.
Common Questions
Can cotton root rot be cured once a tree wilts?
No. By the time a tree wilts, the fungus has rotted too much of the root system to save it. Sprays and soil drenches do not reach the fungus deep in the ground, and extra water does not help. The work that matters is confirming the cause, removing the dead tree safely, and choosing a resistant replacement for that spot.
How do I know it was cotton root rot and not drought?
Speed and pattern give it away. Drought decline builds over weeks and usually hits the whole yard under the same watering. Cotton root rot takes a tree that looked fine and wilts it in a few hot days, often in a rough circle as neighboring plants go next. The dead leaves stay on the branches instead of dropping, and the roots come up soft and rotted with tan strands on them.
Can I replant a tree in the same hole?
You can replant, but not with the same kind of tree. The fungus stays in the soil for years. Put a resistant species in that spot and give it room, or move the new tree well away from the dead circle. Lawns and junipers are not hosts, so they are safe fill for a bad patch while you decide.
Which trees get cotton root rot in North Texas?
Most broadleaf yard trees and shrubs can get it, and fruit trees are hit hard: apple, peach, and pear plantings are classic losses here. It favors alkaline clay, which is most of Collin County. Grasses do not get it, and junipers and other cedars rarely do, which is why they are common replacements in known patches.