The Florida mahogany tree, scientifically known as swietenia mahogani, is the only species of mahogany tree used in the Florida landscape. With its shapely rounded crown, evergreen leaves and striking chartreuse blossoms in early spring, this versatile tree provides good shading and privacy in private yards. Because it doesn't mind salt, it grows well in sandy soil and has good wind resistance. Consequently, it does double duty enlivening coastal highways. A warmer climate tree, the Florida mahogany can be grown in Zones 10 to 11 and is not difficult to grow from seed.
Select a site for your Florida mahogany tree, keeping in mind that the tree can eventually grow to a height of 30 to 40 feet. Your planting site should be at least 20 feet from buildings, and there should not be any overhead wires. If you are growing more than one tree from seed, allow 20 feet between each tree. Florida mahogany trees do best in well-drained soil, either acid or alkaline, in a lightly shaded location.
Soak the mahogany seeds in cold water for 12 hours to hasten germination. Start this project in the fall. According to Tom MacCubbin, author of "Florida Gardener's Guide," it is best to transplant mahogany seedlings in December through February.
Insert seeds a 1/2-inch deep, two to a container, in a mix of half peat moss and half vermiculite. Cover the seeds with sand.
Use a spray mister to moisten the soil.
Cover the containers with plastic to retain moisture, and place under an incandescent light for 12 hours a day. Mahogany seeds germinate 12 to 18 days after sowing, with complete germination within 30 days.
Watch for two sets of two true leaves on each plant after the seedlings emerge. Thin out the smaller of the two plants.
Transplant the seedlings when they are 2 inches high, making sure to work in the shade; direct sun will wither the seedlings' roots very quickly. Loosen the soil in the container around the roots, then pull the seedling gently by the lower leaves. Do not pull from the stem; you can damage the plant.
Transfer the seedlings to a dish of water that is deep enough to cover their roots.
Dig a hole twice as wide around as the root system, and to the same depth where the seedling is now growing. Make sure the hole is deep enough that roots won't curl up.
Put some organic compost in the hole to amend the soil.
Place the seedling in the center of the hole, then pull upwards gently to make sure the roots are straight.
Pack the soil against the roots, starting at the bottom, making sure not to leave any gaps or air holes. Tamp soil down firmly, and mulch well to conserve moisture and protect roots.
Water generously. After your tree establishes itself, it will only need watering in dry weather.
Fertilize the seedlings six weeks after transplanting.