Moving a Large PJM Rhododendron: Digging, Lifting and Replanting

Two PJM rhododendrons stand in the front yard of a corner-lot house whose first-time owners want privacy without a fence. Roger Cook of Ask This Old House says the larger one is as tall as he is and as wide as his arms, and that buying a plant that size, if one could be found, would probably cost 4 or $500. The owners, Mario and Jennifer, want to move it to start a planting screen.

Why these plants suit the spot

Roger identifies them as PJM rhododendrons, hybridized by Peter J. Messett. They are a small-leaf rhododendron, which means they can take sun, and the yard has a southern exposure. The owners say the plants were covered in pink flowers when they saw them in April. The new location lines up between the neighbor's front door and the owners' own entrance.

Choosing the time

Roger calls this a great time of year to move the plant. The flower buds are set for next year, so there should be flowers then. The new growth has hardened off, with no light green growth and one uniform dark color, so the move should not stress the plant.

Preparing the receiving hole

Roger marks the center of the new hole in line between the two doors. His rule of thumb is a receiving hole twice the size of the root ball, so Mario digs a roughly five-foot diameter hole a foot deep, to be adjusted once the ball is out. All the soil goes on one edge, because the shrub will be dragged in from the other side. Roger repeats the saying: "Plant 'em high, they won't die. Plant 'em low, they won't grow."

Lifting the shrub

Roger and Jennifer tie a string around the shrub and pull the branches up to reach the bottom. A spade shovel is used to dig a trench parallel to the marked root ball, cutting roots as it goes, because lifting it without cutting would break everything. Roger asks for the trench sides to be dug straight down rather than sloped. Jennifer then uses a transplanting shovel, which has a long metal blade with a sharp edge for cutting roots and a pad for the foot, driven under the plant all the way around. When the plant still does not move, Roger uses a grub hoe to get underneath it further.

The three tip the plant over, holding it by the string rather than the top, and dig out a little more to release it from underneath before dragging it to the hole.

Setting and finishing

Before committing, Roger measures the root ball at about 12 to 13 inches tall. A string held at ground level across the hole shows the hole is about 12 inches deep, so the plant slides in. After the strings are cut, soil goes in and water goes on right away. Roger adds slow-release fertilizer for next year and super phosphate to promote root growth this year, and has them fill in all the way around before watering.

His watering advice is every day for a week, then every other day during the summer. For the smaller rhododendron, he suggests joining its bad side to the bad side of the big one so they look like one grouping.