Anyone can plant a tree, but to ensure success, sound installation practices must be followed. Use this guide to plant any tree.
General Site Preparation | Planting Container-Grown Trees | Planting Bare-Root Trees | Planting Balled & Burlapped Trees | Planting with a Tree Spade | Post-Planting Care
Initial Considerations
Before you pick up the shovel, review your game plan one more time.
- Have you chosen trees that conform to any and all spatial constraints presented by the site (consider power lines, sidewalks, streets, etc.)?
- Have you chosen trees with the genetic wherewithal to cope with any unique environmental conditions (consider south-facing walls that turn into blast furnaces in summer, wind tunnels, wet areas, etc.)?
- Were your trees purchased from reputable nursery operators (not dug from the woods) and are they of the highest quality?
- Finally, have you made plans to protect trees from mechanical injury, heat and cold, and from drying out during transportation to the planting site and as they await installation?
- Learn more about selecting the best tree for your site from this publication: Guidelines for Selecting Trees
If you can answer yes to all of these questions, then you're ready to plant.
General Site Preparation
Preparing the Planting Hole
Ideally, the planting hole should be two to three times the width of the rootball, container, or root mass (the poorer the soil, the wider the hole), with sides that slope towards the base of the rootball (Fig. 1).
Wide planting holes provide a beneficial zone of well-aerated and well-drained soil that tree roots will readily exploit during the establishment period. In addition, sloped walls help direct growing root tips upward to the surface rather than in a circling pattern. Hole depth should allow the tree to be positioned so that the root collar or trunk flare is level with, or slightly higher than the surrounding grade. Never dig the hole deeper than the height of the rootball or root mass because the tree may settle deeper into the hole than intended. Planting too deep, either intentionally or unintentionally, can cause trees to die within months of installation, or lead to other chronic problems (girdling roots, stem or trunk rots, etc.) that significantly shorten their lives.
Dealing with Poor Soil
But what about planting trees in new housing developments where the "growing medium" is compacted clay subsoil? When confronted with situations where drainage is poor and soil oxygen is in short supply, only species tolerant of these challenging conditions should be used. Alternatively, you might install expensive and elaborate subsurface drainage systems or plant trees in raised berms (natural-appearing landforms composed of good topsoil).
If trees must be planted directly into poorly-drained or compacted soils, a wide, shallow hole should be prepared so as much as one-third of the rootball or root mass protrudes above the surrounding grade (Fig. 2). This technique raises the zone of active root growth above potentially saturated, oxygen-deficient conditions.
Don’t Backfill with Amended Soil
Contrary to popular belief, soil removed from the planting hole is the most appropriate backfill material. Soil amendments like peat moss, ground bark, and composted manures mixed with the native soil and used as backfill have not proven beneficial to tree establishment. In fact, studies have shown tree root systems in amended soils remain confined to the amended soil in the planting hole, while trees planted without the "benefit" of soil amendments developed roots far beyond the original planting hole.
And on poorly-drained sites, soil amendments can collect too much water. Because amended soil has greater pore space than surrounding clay soil, water will move into it preferentially. During periods of heavy rainfall, the amended planting hole can fill up with water like a bathtub, causing root suffocation and tree death.
Planting Container-Grown Trees
Container-grown trees are very common and frequently purchased by homeowners. Always handle trees by the container, not the stem or trunk.
Find the Trunk Flare Before Beginning
To determine proper hole depth, examine the rootball to locate the trunk flare. Occasionally the base of the trunk is covered by too much soil when placed in the container. Trees can be planted too deep when the planter assumes the top of the rootball is the appropriate depth. Look for the flared trunk base that increases in diameter as it meets the ground. Also, look for roots. If these features aren't immediately apparent, scrape the soil away until fibrous roots are discovered. Now the true depth of the root system can be determined and an appropriate hole can be prepared.
Carefully Remove the Container
But before backfilling begins, all containers must be removed from the rootball or root mass. Even the so-called "plantable" or paper mache containers should be removed to keep them from interfering with root growth and drainage. When planting a large tree, or if a tree is poorly established in the container (a common problem when container-grown trees are purchased in early spring), the planting operation is made easier by first, cutting away the bottom of the container, and then lowering the rootball into the hole before removing the rest of the container.
Remove Any Circling Roots
Occasionally, container-grown trees may become pot-bound or root-bound (roots dense and circling). If not corrected, this condition can restrict root growth development into the surrounding soil and make it difficult to wet the original root mass. Several vertical cuts made the length of the root mass will disrupt circling roots and lessen the chance for girdling roots later in the life of the tree. Often it is beneficial to “square off” or “shave” the outside of the rootball to remove all circling roots and leave behind only root tips pointed straight outward.
Backfill with Soil and Water Well
Now backfilling can be completed, gently firming the backfill soil with your hands. Because dry rootballs will result in poor growth, a thorough watering is essential for the newly planted tree. Make sure the backfill soil is thoroughly watered to eliminate air pockets.
Planting Trees in Fabric Containers
Several fabric containers, using various designs and fabrics are used and are sometimes referred to as “grow bags.” Fabric containers are not plantable or compostable. If trees are received with grow bags attached to the root balls, they must be removed at planting to prevent possible root deformation and prolonged restriction of nutrient and carbohydrate movement.
See the entire process in this video: How to Plant a Container Grown Tree
Planting Bare-Root Trees
Damaged, broken, or excessively long roots should be pruned from bare-root trees prior to planting. When positioned in the hole, root systems should not be twisted, bent, or kinked. Planting bare-root trees is made easier by building a firm, cone-shaped mound of soil at the bottom of the hole. When roots are spread evenly over the mound or pedestal, the ground line on the trunk (indicating previous planting depth at the nursery) should be at, or just above the surrounding grade. After proper depth has been determined, backfill soil can be added, taking care to work the soil around the roots. Watering the backfill when three-fourths completed, and again when the backfill matches the surrounding grade, will eliminate undesirable air pockets.
Caution: Do not place excess soil, especially clay-type soil, over the planting site. When heaped over the plant roots, clay soil forms a layer that oxygen and water cannot readily penetrate. Adding clumps of turfgrass in the "overfill" should also be avoided.
More details on planting bare root trees can be found in this article: How to Plant Bare Root Plants
Planting Balled & Burlapped Trees
Balled & burlapped (B&B) trees must be handled carefully to prevent damage to the trunk and to the roots inside the rootball. Trees should always be handled by the rootball and not by the stem or trunk.
Find the Trunk Flare Before Beginning
To determine proper hole depth, examine the rootball to locate the original "ground level" at which the tree was growing in the nursery. Repeated cultivation in the nursery sometimes causes extra soil to accumulate around the trunk, disguising the original grade. Trees can be planted too deep when the planter assumes the top of the rootball is the original ground level. Peel back the burlap from the top of the rootball and look for the flared trunk base that increases in diameter as it meets the ground. Also, look for roots. If these features aren't immediately apparent, scrape the soil away until fibrous roots are discovered. Now the true depth of the root system can be determined and an appropriate hole can be prepared.
Place the Tree in the Planting Hole
Balled & burlapped trees should be gently lowered, not dropped, into the prepared hole. If plastic or poly-burlap has been used to encase the rootball, it should be removed before backfilling begins. These materials interrupt water movement from the surrounding soil into the rootball, and also may restrict root growth.
Do I Leave the Burlap and Wire Basket On or Not?
Deciding which other support-lending materials to remove from the rootball before backfilling begins is handled on a case-by-case basis. If the rootball is exceptionally sturdy, all burlap, sisal, and synthetic twine, and the wire basket can be removed before backfilling begins, however, removing these materials at this stage may result in the loss of rootball integrity and cause root damage. A safer method involves backfilling layers of soil around the rootball until one-half to two-thirds of the planting hole is full. Then, all twine from around the trunk, and the top one-third of the wire basket can be removed from the rootball to eliminate the possibility of root or stem girdling. Use a bolt cutter to remove the top portion of the wire basket, if needed.
Next, the burlap covering the top one-third of the rootball can be cut away to allow free movement of water into the rootball. Removing the burlap is preferred over simply folding it back into the planting hole because a burlap "wad" two or more layers thick may form which could hamper root egress in the first few months after transplanting.
Backfill with Soil and Water Well
Now backfilling can be completed, gently firming the backfill soil with your hands. Because dry rootballs will result in poor growth, a thorough watering is essential for the newly planted tree. A "deep-root" feeder or watering needle can be used to force water throughout the rootball to "recharge" it and promote root development. Also, make sure the backfill soil is thoroughly watered to eliminate air pockets.
Planting with a Tree Spade
Trees transplanted with a tree spade generally respond like B&B trees, however, if the planting hole is dug with a tree spade in clay soil and the sides of the hole become glazed, some roots could have trouble growing into the surrounding soil. To alleviate this problem, enlarge the hole before planting so roots can penetrate the loosened backfill soil. Lower the spade with the root ball into the hole and partially fill in around the spade with loosened backfill soil. Firm the soil and add water to settle. Trees moved with a tree spade into loamy or sandy soils can usually be planted into the "spaded hole" with little, if any alterations to the hole. The tree often ends up a little higher than the surrounding grade, which is certainly much better than planting too deeply.
The Establishment Period - Post-Planting Care
In USDA hardiness zones 4 and 5, the establishment period lasts about 12 months per inch of trunk diameter. For a two-inch caliper tree, this translates into a 24-month establishment period. Newly-planted trees need active and frequent care during the entire establishment period.
Consistent and proper care during the establishment period is the single most important thing you can do to have success with your new tree.
Proper Watering is Essential
Proper water management is crucial for newly-planted trees. Recent evidence suggests frequent irrigation provides more benefit than applying large volumes of water infrequently. This is in direct contrast to the recommendation for established trees where occasional irrigation with large water volumes is considered better than light, frequent applications. Be sure to gradually increase the area irrigated around the tree to accommodate root growth.
Should I Stake the Tree?
Bare-root trees and those planted in windy, exposed sites may require staking for support. Staking materials should not girdle or injure the stem and should allow some trunk movement or sway. When possible, stakes should be removed after one year of service.
No Need to Prune at Planting
Severe pruning at planting time is unnecessary and may reduce the growth rate of developing roots. Remove only dead, broken, or rubbing branches.
Mulching is Highly Beneficial
Mulching the area around newly-planted trees with pine needles, wood chips, shredded bark, or slightly decomposed leaves (2 to 4 inches deep) is highly recommended. Mulching increases tree growth by reducing turfgrass competition, conserving soil moisture, and reducing the chance of mechanical injury from lawn mowers and string trimmers. The only precaution is to keep mulch several inches away from the trunk so it will not rot the trunk.
When to Fertilize
Finally, ensuring good aeration for developing roots through proper planting techniques and providing adequate moisture to the root zone and surrounding backfill are far more important than applying fertilizer at planting time. Fertilizer is more appropriately applied at the beginning of the second growing season.
More Information
More detailed information on post-planting care of trees can be found in this article: Care of Newly-Planted Trees
