The name says it all. Bare-root nursery stock are trees and shrubs that are field grown for one to three years, undercut and dug in fall and spring, handled with no soil left around roots, and stored with moist roots and dormant tops at a temperature a few degrees above freezing until they are planted says Kathy Zuzek, University of Minnesota Extension Educator.
Bare-root stock offer several advantages: Bare-root plants are usually one-half to two-thirds of the cost of containerized or balled and burlapped plants because bare-root plants are easier to handle, store, and ship; Longer root lengths are possible on bare-root plants since weight of the soilless root ball is minimal; The entire root system of a bare-root plant can be inspected so deformed, circling, and broken roots can be detected and corrected or removed; Appropriate planting depth is easy to gauge because the root system is visible; Because there is no soil around the root zone, there is none of the dramatic change in soil interface between the rootball and native soil that can hinder plant establishment.
There are also disadvantages to planting bare-root trees and shrubs: The range of plant sizes and plant types in bare-root plants is smaller. Bare-root trees are usually a 2 inches caliper or less, because larger sizes do not transplant well as bare-root plants. Caliper is the diameter of a tree stem, measured 6 inches above the ground. If that stem diameter at 6 inches above the ground is greater than 4 inches, move up the stem another 6 inches and measure the diameter at 12 inches above the ground for your caliper measurement. Evergreens are not sold as bare-root plants unless they are very small seedlings; Bare-root plants should be dormant when planted so there are seasonal restraints to planting;
Early spring between the time that the ground thaws but before bud break is one time to plant bare-root plants. Autumn is a second good time to plant bare-root stock. Soil temperatures and moisture levels encourage active root growth at these times of year and lower air temperatures and dormant crowns help to minimize transplant shock.
Careful handling of bare-root stock is important. The exposed root system cannot be allowed to dry out during handling, transporting, or planting. Keep the roots moist and protected from wind and sun. If you can't plant immediately, place the plant in a cool, shaded, sheltered location and cover the roots with moist straw, hay, damp burlap, or loose moist soil. Bare-root plants lose up to 95 percent of their roots when they are undercut and removed from a nursery. After transplanting it is hard for this reduced root system to absorb enough water to meet the needs of the plant. Until the root system grows and reestablishes to its normal size, a newly planted tree or shrub often experiences transplant shock, which is primarily drought stress. You should plant and care for your bare-root plant in a way that provides the optimal environment for root growth and replacement during the first few years after transplanting.
Optimal planting and care include: a planting hole only as deep as your root system's height. This prevents settling and all of the stresses caused by deep planting; a planting hole at least two to three times as wide as the root ball that allows for rapid root growth through the backfill soil before hitting growth-slowing compacted soil outside of the hole; a planting hole with sides that slope towards the base of the hole. The majority of a woody plant's roots grow in the top foot of soil and a planting hole with sloping sides encourages new roots to grow horizontally and toward surface soils; a planting hole backfilled with the original soil. Adding amendments to improve soil quality doesn't help and sometimes hurts by causing poor water drainage in the planting hole. Your time is better spent digging a wider planting hole than amending soil.
Water is usually the most limiting factor affecting plant growth after transplanting. Because your bare-root plant has lost the majority of its root system, it relies heavily on water in the root ball through the first growing season. For a bare-root tree with a caliper of 2 inches or less that is planted on a well-drained site, apply 1 to 1 1/2 gallons of water per inch of stem caliper daily during the first week after planting, then every other day for 1-2 months , and weekly after that until the plant is established.
For more information regarding gardening, you can reach me by email Stephanie@starpoint.net