Some kinds of woody plants have root systems that won't survive bare-root transplanting; some are evergreen and cannot be bare-rooted. Instead, such plants are dug from the growing field with a ball of soil around their roots, and the soil ball is then wrapped in burlap or a synthetic material and tied with twine or wire. These are called balled-and-burlapped plants (B-and-B plants for short). Some deciduous trees and shrubs (large specimens, in particular), evergreen shrubs such as rhododendrons and azaleas, and various conifers are sold this way in fall and early spring.
Buying and handling tips
When buying B-and-B plants, look for healthy foliage and an even branching structure. The covering should be intact so the roots are not exposed, and the root ball should feel firm and moist. If you have any doubts about the condition of the root ball, untie the covering and check for healthy roots and a solid, uncracked root ball.
B-and-B plants can be damaged if handled roughly. Always support the bottom of the root ball when moving the plant; don't pick the plant up by the trunk or drop it, which might shatter the root ball. Because a B-and-B plant is usually quite heavy, it's a good idea to have the nursery deliver it to you or to have a friend help you move it to and from your vehicle in a sling of stout canvas. Once home, you can move the plant by sliding it onto a piece of plywood and pulling it to the planting spot.
Planting balled-and-burlapped plants
1. Measure the root ball from top to bottom. The hole should be a bit shallower than this distance, so that the top of the root ball is about 2 inches above the surrounding soil. Adjust the hole to the proper depth; then set in the plant.
2. Untie the covering. If it's burlap, it will eventually rot and need not be completely removed; just spread it out to uncover about half the root ball. If the covering is a synthetic material, remove it entirely. If you are planting in a windy site, drive a stake in alongside the root ball. Fill the hole to within 4 inches of the top and water gently.
3. Continue to fill the hole, firming the soil as you go. Make a berm of soil to form a watering basin; then water the plant. If you staked the plant, loosely tie it to the stake. As the plant becomes established, keep the soil moist but not soggy.
Soil texture considerations
While most shrubs and trees grow best if planted in the soil native to your garden, B-and-B plants are sometimes an exception. They are generally grown in clay or heavy soil that holds together well when the plants are dug up and wrapped.
If you have medium- to heavy-textured garden soil (such as fairly heavy loam or clay), there's no need to amend the soil you return to the planting hole. But if the B-and-B soil is denser than that in your garden, the plant may have a hard time getting established, since the dense soil around its roots will absorb water more slowly than the surrounding garden soil: the B-and-B's soil can be dry even if the garden soil is kept moist.
To avoid this problem, mix an organic amendment such as peat moss, ground bark, or nitrogen-fortified sawdust into the soil removed from the planting hole, using about one shovelful of amendment for every three shovelfuls of soil. Use this blend to fill in around the roots.