Royal poinciana (Delonix regia) produces bold, red flowers, making it a true shower stopper the few weeks it’s in bloom in spring and summer. Like other trees, the younger and smaller the royal poinciana is, the easier and more successful transplanting it will be. Because it’s a faster grower -- up to 5 feet in one year -- don’t wait too long to move it. In U.S. Department of Agriculture plant hardiness zones 10 through 12 where royal poinciana grows, you can transplant it fall through spring when the weather is mild.
Use a spade to cut into the soil 10 to 15 inches deep. Dig a circle around the royal poinciana two to six months before transplanting it. Do not cut under the tree at this time. You are pruning its roots so the tree is more likely to survive the transition. The diameter of the cut around the tree varies depending on its size. A 12- to 15-inch circle is minimum, but for a tree that stands 5 feet or taller, you'll need to create a circle that is at least 18 inches wide.
Water the royal poinciana two or three days prior to moving it. Give it a good soaking with about 1 inch of water. The tree will now be hydrated for the transplanting process.
Dig a 18- to 24-inch deep hole in a location that is exposed to full sun. It should be two times as wide as the root pruning cut you made six months earlier. Royal poinciana tolerates most soil types, but it prefers soil that is well draining. Mix compost into the tossed soil to make up 25 percent of its total volume.
Slice into the soil around the royal poinciana at the same distance as the root pruning. This time, cut under the tree. Pull up on the trunk and push down on the spade to lift the tree from the soil. Depending on the size of the tree, this might be a job for more than one person. Wrap a tarp or burlap around the root ball and move the tree to its new location. A wheelbarrow may work well for transporting.
Measure the depth of the root ball. Add or remove soil from the hole so it is just as deep as the root ball. Set the royal poinciana in the center of the hole. Backfill the soil that you amended with compost around the sides of the tree. Tamp it lightly as you go. Water the tree with 1 inch of water after you fill in the hole half way. Continue to backfill the hole until you reach the top of the root ball, and water again with 1 inch of water.