Fall is the best time of year to transplant trees, shrubs and perennials. Plants spend the spring and summer growing shoots, branches and leaves, but during cool weather they concentrate on root growth.
You'll need professional help to move large trees and bushes from one place to another in your garden. Your local nursery or arborist should have access to a spade digger, a machine that digs up full-size trees. Small shrubs and perennials can be managed by most home gardeners though you may be surprised at how heavy even a small plant can be.
Before digging up any plant decide on its new location. Dig a large hole, making sure it's wider and deeper than the root ball of the plant you're moving. Adding compost and a phosphorus-rich fertilizer to the soil at the bottom of the hole will help the transplant develop a strong root system.
Use a sharp spade or shovel to dig up the plant and have a tarp or wheelbarrow handy to help move it. Avoid digging too close to the main stem or trunk or you might chop off too many roots. Don't worry if you lose a few - plants are very resilient and new roots will grow to replace any damaged in the move.
Be careful not to bury your plant too deep. The soil should come to the same level as before. A three-inch layer of mulch or pine bark placed around the plant will help protect the roots from freezing in the winter. Give the plant a good long soak to help eliminate air pockets as soon as it's in the ground. Continue watering deeply for a couple of weeks after the move and then weekly until the ground freezes.