Oak wilt is a fungal disease that affects the water conducting system of red, white and live oak trees. This disease was discovered in 1961 in Dallas but wasn’t diagnosed definitively until the 80’s. It had the potential to be the most destructive disease in the US but has been most devastating in the state of Texas. We are just past the worst time to prune oak trees, February to June. Wounds can be an entry point for the sap eating beetle. You can paint the branches you prune with even an inexpensive latex spray paint. Oak roots can clone an overlay another root system so this disease can spread as far as 200 yards away. The veins of the leaf turn orange so this is you first indication that the sease is present and this disease spreads and kills the tree quickly so preventing it from spreading to other oaks is most important. Removing and burning the tree is best as heat kills the fungus. Texasoakwilt.org is a good website to learn more.
Texas A & M AgriLIfe has a handbook that lists all the diseases including many funguses of different species of trees in Texas. Your local agriculture extension office is a good source to help you diagnose the problem. You can send them a picture or take in a sample.
When you decide to plant a tree you should do your homework and consider the mature size of the tree and the crown and if it will fit in your landscape and if it thrives in the Houston climate and zone. A benefit in this hot climate is for the tree to provide shade. Fruit producing trees can be nice for they can be messy and some, for instance cherry will not grow here as it doesn’t get cold enough for them to produce fruit.
It might be beneficial to learn what are the worst trees to plant. Starting with fruit trees–the Bradford Pear has beautiful flowers in the spring but they smell like rotting fish. The structure is weak and leaves debris whenever there is wind and the trunk is susceptible to cracking. If it is in your yard for some reason grass does not grow under this tree. A Mulberry has an aggressive root system and will come up everywhere in your yard and will even try to come up under your driveway or sidewalk causing cracks. Other negatives are the male trees produce a tremendous amount of pollen and they are prone to insects. Besides being a weedy tree, the Hackberry shares the same problem of attracting insects especially woolly aphids and also has an invasive root system. Many new home builders choose a Japanese Blueberry because they grow quickly but are prone to soot a black powdery airborne fungus that cannot be treated.
An exotic tree that was brought to the US in 1745 from China is the Mimosa. They have pretty pink flowers for a few weeks in the spring but the rest of the year it has big brown seed pods that are messy and can spread quickly. A popular tree in Houston is the Ash. It grows quickly but will be a worry during hurricane season as it is brittle. Also they are susceptible to the emerald ash borer that dcam from Asia. They have not been a problem yet in Houston but are in the Northeastern part of Texas so will inevitably spread. Another non native invasive tree from China is the Chinese pistache that became very popular in North Texas but once mature the female produces a red fruit that turns blue. The birds like them and spread them everywhere. Although the tree is beautiful with bright red or yellow fall foliage it is now on the official state and national invasive species list. Good native choices are the prairie flameleaf sumac and the bigtooth maple. And even though there are many of them already, the Texas red oak is also an excellent tree.