Ask Mr. Smarty Plants

From the Lady Bird Johnson Wildflower Center website, our native plant database has some great information about the mighty bur oaks. Here's some that might be of help with your young tree.

Bur oak (Quercus macrocarpa) is a large, deciduous tree with a very wide, open crown. Usually wider than tall, the tree can exceed 100 ft. in height and width. The massive trunk supports heavy, horizontal limbs and rough, deep-ridged bark.

The acorns of this species, distinguished by very deep fringed cups, are the largest of all native oaks. The common name (sometimes spelled Burr) describes the cup of the acorn, which slightly resembles the spiny bur of a chestnut. Bur Oak is the northernmost New World oak. In the West, it is a pioneer tree, bordering and invading the prairie grassland. Planted for shade, ornament, and shelter belts.

Widely distributed and capable of withstanding a wide range of harsh conditions (one of the most drought resistant oaks) throughout eastern North America; usually found on limestone or calcareous clay. Various soils & moisture conditions. Sandy, sandy loam, medium loam, clay loam, clay, caliche type, and limestone-based soils.

Bur oak is drought resistant, long-lived and reasonably fast-growing for an oak. Tolerates limey soils better than other oaks. Resistant to oak wilt and a number of other problems. Sensitive to root zone disturbance caused by construction. A shade tree, attractive, fast growing, long-living. A good urban tree since it is resistant to air pollution and car exhaust.

Attracts songbirds, ground birds and mammals. Substrate for insectivorous birds, Fruit for birds, mammals, rodents, and deer.

Also online at the US Forest Service is an informative factsheet on the bur oak.

Prefers full sun. This Oak will adapt to various soils where other Oaks sometimes fail but is difficult to transplant from well-drained soil due to the tap root. As with most trees grown in urban areas, the tap root becomes much less prominent as the tree grows older, giving way to a more shallow, horizontal root system. It is well adapted to alkaline soils, poor drainage, high clay content, and is very drought-tolerant.

And on the Aggie Horticulture at TAMU website, additional information is available on the culture of bur oaks in Texas.

Bur oak is a majestic tree of the tallgrass prairie that once covered central North America. It grows best in deep limestone soils of riverbanks and valleys but it will adapt to many different environments. It has a long taproot which makes it hard to transplant but also very drought-tolerant. It is also fast growing and long-lived.

In summary, I would suggest carefully digging down to where the young tree roots are located before you water and look at their condition. Are they healthy and fibrous? Is the soil around the roots wet or dry? Is the tree planted too deep? A visual investigation will help with a diagnosis of what is ailing your young tree.