With roots as deep as the tree is tall, pecan trees need deep soil to thrive. They are native to river bottoms so require substantial water during the growing season. Although they are water lovers, they don't like soggy roots so well-drained soil is essential to their survival. Pecan trees are a species of hickory and native to the United States.
Water the new pecan tree with 7 gallons of water a week for its first year. Growers at Texas Pecan suggest watering slowly and deeply once a week. At age 3, provide 21 gallons of water a week. When the tree reaches 4 years of age it should receive 63 gallons of water a week. Give the mature tree 100 to 250 gallons of water per week during the summer. When the temperature rises above 95 degrees F, or high winds are drying the soil, double the amount of water.
Fertilize the pecan tree in late March and mid-May with 10 lbs. of ammonium sulfate. Apply the fertilizer immediately after watering by using a broadcast spreader to sprinkle it on the soil. Spread the fertilizer beneath the tree and 1 foot past the dripline. Water lightly after application and decrease the weekly irrigation amount by half for the next three weeks.
Spray the pecan tree's foliage with a zinc spray in the spring. Repeat the application every three weeks until mid-June. Avoid spraying the tree during the hottest part of the day. Apply the zinc spray at the rate suggested on the label for the size of your tree.
Prune off suckers (new shoots) growing at the base of the tree. These can generally be removed by hand or with pruning shears any time of the year. Prune off all lower branches that are lower than your head so that the bottom of the tree is open enough for you to stand under it. Remove any dead branches using loppers or a tree saw.
Apply insecticidal soap, at the rate suggested on the label, to control aphid infestations.