Often, as a landscaping plan evolves and matures, the need to discard or transplant old shrubs and to plant new ones arises. Techniques for accomplishing these tasks are shown on these and the following pages.
Moving an old shrub—or planting a new one—is best done in early spring or fall. A few days before transplanting a shrub, water it generously to soften the soil around its roots, then proceed as shown on the next page. Have a tarpaulin on hand to help move the shrub easily, and plastic sheeting to keep soil off the lawn.
Except for some flowering shrubs—rhododendron and laurel, for example—which can be propagated through a technique called layering (page 94)—new shrubs come most often from nurseries. The plants come in three forms: rooted in a ball of soil and wrapped in burlap; grown and rooted in plastic containers; and with bare roots.
Choose shrubs suited to your climate and soil conditions (see appendix) and check their condition carefully. Sound, undamaged bark and bright foliage on well-shaped branches spaced evenly around the stem are signs of a hardy specimen. Reject plants that have broken branches, bruised bark, or pale leaves, or those that are growing in dry soil.
Ask a nursery worker to show you the roots of container-grown plants. Look for a thick profusion of roots at the rootball’s bottom; reject a shrub with roots that coil around the rootball or protrude from the top—sure signs of being potbound. In a healthy burlapped shrub, the rootball has a firm, solid feeling, with moist soil and no weeds. Bare-root stock should be undamaged, clean smelling, and uniform in color.
Plant shrubs immediately if possible, or store them in shade and keep the roots moist; if you cannot plant a bare-rooted shrub within a week, bury it in a shallow trench and keep it watered until you can plant it permanently.
Shrubs are heavy; lift with the arms and legs and wear a back brace to reduce risk of back strain. Gloves protect your hands during spade work.
Digging out the roots
Cut off most of the shrub’s outer branches with pruning shears and trim main stems to a length of 2 or 3 feet. With a mattock, dig a trench around the shrub 1 foot or more from the stem and extending down through the root system. Undercut the shrub with a spade or digging bar to sever all the roots, then pull out the shrub by the trunk.
Refilling the hole
Knock the soil off the roots and into the hole with a spade or garden fork. If the plant is diseased, spread plastic sheeting in the hole to collect the soil and dispose of it away from the yard and garden. Refill the hole with soil and tamp it firmly. Add more soil to form a loose mound 4 to 6 inches high; the soil will settle in a few months, leaving the area level.
Defining the rootball
Wrap the plant with twine to gather the branches into a compact bundle. Score the ground with the point of a shovel or spade to mark a circle roughly the diameter of the wrapped plant; this defines the size of the rootball. Make another circle about 9 inches outside the first.
Cutting out the rootball
Lay a canvas tarpaulin or sheet of heavy plastic next to the outside circle to receive the soil. Dig out the soil between the two circles to the depth of the shrub’s main roots, usually about 18 inches. Undercut the rootball all around the plant with the spade or shovel, freeing it.
Wrapping the rootball
Cut a square sheet of natural-fiber, biodegradable burlap about 3 times the diameter of the rootball and place it next to the hole; do not use synthetic fabric or plastic. Push against one side of the rootball to tip the shrub on its side and stuff at least half of the burlap under the tilted rootball (above, left). For large shrubs, consider enlisting a helper. Tip the ball toward the opposite side of the hole, then pull the burlap from under the ball (above, right), roughly centering the ball on the burlap square. Lift the edges of the burlap and tie them securely around the stem with twine.
Pulling out the shrub
Set a sheet of canvas or heavy plastic next to the hole and lift the shrub onto the sheet. You may need a helper to assist in moving medium-sized or larger shrubs. Carry or slide the shrub on the sheet to its new location. Before replanting, unwrap the branches but leave the rootball in the burlap. Cut away any broken branches and prune the shrub by about a third to compensate for any roots lost through digging it up. Refill the old hole with soil.
Digging the hole
At the new location, dig a circular hole about twice as wide and half again as deep as the rootball. Pile the soil on a plastic or canvas sheet next to the hole.
Conditioning the soil
Add peat moss and other amendments to the soil that was removed. Blend the soil and other materials thoroughly, keeping the mixture on the sheet and off grass or ground cover. Soil recipes: For loamy soil, add one part peat moss to two parts soil; for clay soil, add one part peat moss and one part sand to one part soil. For sandy soil, mix equal amounts of peat moss and soil. To any of these mixtures, add slow-release fertilizer in the amount recommended on the package.
Making a base for the shrub
Shovel a layer of the conditioned soil into the hole and compact it with your feet or a tamper. Repeat the process, partially filling the hole to a depth about 2 inches shallower than the height of the rootball.
Positioning the shrub
Set the shrub in the hole, adjusting the bottom as needed to make the main stem vertical. Lay a straight stick across the hole to make sure the top of the rootball is about 2 inches above ground level. If the shrub sits too high or too low, lift it out of the hole and add or remove conditioned soil to bring the shrub to the right height. Add soil mixture to the hole around the rootball, tamping as you go, until the hole is two-thirds full. Then loosen the burlap and spread it over the soil mixture (inset). Fill the hole with water, and let it seep into the ground. Then add soil mixture to about 1 inch above ground level and tamp it down firmly.
Forming a basin of soil
Build a soil dam about 4 inches high around the planting hole to catch water for the shrub. Fill this basin with water and let it seep into the soil. Spread a 2-inch layer of mulch or bark chips around the shrub. Cover the basin walls but stop 2 inches short of the main stem. Keep the soil moist around the transplanted shrub for the first few months, but do not overwater.
Wounding the branch
In early spring, bend a healthy lower branch to touch the ground about 12 inches from the tip and dig a bowl-shaped hole about 6 inches deep there. Bend the branch into the hole. Where it touches the center of the hole, slit the branch diagonally about halfway through with a sharp knife and wedge a twig in the cut (inset). Sprinkle the wound with rooting powder, a synthetic hormone available at garden centers.
Anchoring the branch
Mix enough topsoil, peat moss, and sand, in equal parts, to fill the hole, then put about one fourth of the mixture into the hole. Bend the branch back into the hole with the cut facing down and cover it with soil mix. Anchor the branch with a pair of crossed sticks (left), and fill the hole with the remaining soil mix, making sure that 6 inches of the branch protrude above ground level. Water the soil mix thoroughly and set a rock over the crossed sticks to hold them in place.
Separating the new shrub
Do not disturb the branch until next spring, then dig it up. Pull away some soil to see if roots have developed at the cut. If three to five roots are present, sever the branch to free the new plant from the old one (right); if not, rebury the branch and check again in the fall. After detaching the branch, push gently on the rootball to slant the roots in the opposite direction from the tip. Plant the newly propagated shrub as you would any other, tilting the rootball so that the top of the plant points upward.