The mahogany tree (Swietenia macrophylla) is one of nature's larger specimens. Mature trees can reach heights of 150 feet and boast trunks measuring up to 6 feet in diameter. The fissured bark of the tree disguises magnificent wood that is the crème de la crème of woodworking. If you live within U.S. Department of Agriculture plant hardiness zones 9 through 11, you can grow mahogany as long as you have a sunny planting site with well-drained soil.
Prepare your planting site in advance. Loosen the soil to a depth of 18 inches using a pitchfork. Check the pH of the soil at that level using a soil test from an established soil laboratory. Tell the laboratory that you are testing for a mahogany tree. Mahogany trees prefer soil with a pH in the slightly acidic to near-neutral range of 6.1 to 7.4.
Amend the soil in the planting site only if the soil pH is not within the mahogany tree’s preferred range and the soil laboratory recommends a change. If changes are needed, follow the laboratory's recommendation for the type of amendment and the amounts needed to adjust your specific soil. The amounts and substances vary widely depending on your soil type and current pH.
Dig the hole for the mahogany tree. Make the hole twice the width of the plant's current container in order to give the roots plenty of room for expansion. The depth of the hole should match that of the tree's root ball in its present container. Leave the bottom of the hole solid to give the plant support.
Tip the mahogany tree on its side, and gently slide it out of the nursery container. Leave the roots and attached dirt intact. Stand the mahogany tree upright, and set it in the center of the planting hole.
Place the tree so that the root flare at the base of the trunk is above the soil line. If necessary, add more soil to the bottom of the hole to raise the tree so the root flare sits slightly above the surrounding grade.
Backfill the hole halfway with soil. Fill the remainder of the hole with water from a garden hose and allow it to drain and secure the roots of the mahogany tree. Continue backfilling the hole once the water drains.
Tamp down the soil lightly around the trunk of the mahogany tree using your hand to remove air pockets. Spread a 3-inch deep layer of bark chip mulch around the trunk to help retain soil moisture and protect roots from temperature fluctuations.
Water the mahogany tree with at least 1 inch of water per week for the first two growing seasons. A soaker hose works well to deliver the water slowly. Once the mahogany tree establishes itself in the soil, supplemental watering is only required during drought.