Ask Mr. Smarty Plants

For starters, the closest states where Carya illinoinensis (Pecan) grows natively are Texas, Oklahoma and Kansas, as you can see from this USDA Plant Profile Map. The Lady Bird Johnson Wildflower Center, home of Mr. Smarty Plants, only recommends plants native to North America as well as the area in which they are being grown; in this, case Fresno County, CA. This is because a plant native to the climate, soils and rainfall where it is growing will require the expenditure of fewer resources like water, soil amendments and fertilizer.

So, which came first, the deck or the tree? Is the deck concrete? Here are the Growing Conditions of Carya illinoinensis (Pecan).

"Water Use: High
Light Requirement: Sun
Soil Moisture: Moist
CaCO3 Tolerance: Low
Cold Tolerant: yes
Soil Description: Rich, moist, well-drained soils. Sandy, Sandy Loam, Medium Loam, Clay Loam, Clay, Caliche type
Conditions Comments: The sweet, edible nut, makes pecan the best hickory for fruit production. The tree does not bear liberal quantities of fruit in the northern part of its range, but makes an interesting ornamental there. Susceptible to galls, twig girdlers, aphids, borers, weevils, pecan scab, tent caterpillars, and webworms. Slow-growing. Difficult to transplant because of a large taproot."

Notice the last line of those conditions. Many people ask us for taproot trees to be planted near a pool. In actuality, even a taproot tree has many feeder roots going in all directions, not only in search of nutrients and water but also to balance the tree and keep it upright in the soil. Follow this plant link Carya illinoinensis (Pecan) to our webpage on the tree to find out more about it. The tree can get ovef a hundred feet tall and we can tell you that it will work on surviving and its roots will almost certainly attempt to crack up the deck in order to facilitate not just the access to soil nutrients and water but also gas exchanges of oxygen and carbon dioxide at the soil surface.

We would also mention that a large deciduous tree in the vicinity of a pool is a mess in the making. Being deciduous, it will be dropping lots of large leaves, twigs and blossoms onto and into the water every year.

Final word: these two, deck and tree, are truly not compatible. If the tree is small, you might sacrifice it by taking it out. Transplanting is difficult, as noted above, because of the taproot. You might not live there long enough to deal with the possible ultimate height of 100', but that is pretty large for a regular residential lot. If you just leave it alone and let them work it out. you are likely to end up with a dead tree or a badly damaged pool area.