Updated: Jul 25
Trees are the most expensive living item we plant in the landscape. How a tree is planted will influence how well it will perform in the future or if it will even survive. Here is my advice for folks in the northeast who want to ensure the trees they buy will continue to add value to their property long into the future.
WHEN TO PLANT
The best time to install a tree is while it is dormant. Trees are dormant in the fall after dropping their leaves and in early spring before bud break. Therefore, you can plant most trees in the spring until mid-May in the northeastern portion of the US. Although not ideal, they can be planted in the fall until mid-September after the summer heat and droughty conditions have subsided.
Transplant shock is a condition of reduced growth and vigor after the digging and handling of balled-and-burlapped trees. Trees lose a significant part of their roots in the transplanting process. Container trees can also experience transplant shock by the way they are handled. For example, lifting a tree by the trunk or dropping it in the container can set it back or kill it.
Proper handling, soil prep, installation, and maintenance can limit the amount of transplant shock a tree goes through. In addition, a tree will be attacked by numerous insects and diseases while in a weakened state. Therefore, you want to reduce transplant shock as much as possible.
Where to Plant a Tree
When planting a tree, you must consider buildings, homes, utility lines and structures, walkways, driveways, and fences. I recommended remaining a minimum of 25' away from any building to avoid heaving or damage from roots. Proper tree placement can enhance the value of your property, save on cooling costs, and stabilize the soil.
Ideally, you want to plant a tree in an area that drains if you can. If the only place you can grow is in a poorly draining location, a tree that can handle wet feet should be selected. Some native examples would be Bald Cypress Taxodium distichum, Swamp White Oak Quercus bicolor, and Sour Gum Nyssa sylvatica
DEALING WITH UTILITIES
Before planting your tree, the first step is to make sure you have located all underground utilities before digging. The US national call-before-you-dig phone number is 811. You could avoid a costly or dangerous situation by contacting the utility marking professionals, so play it safe. Never assume that you know where the utilities are located. Most importantly, locating underground utilities before digging is often required by law.
Trees are like icebergs; most of their structure isn't visible. The root mass can extend way past the spread of the branches and can grow deeper than its height. Utilities installed underground can be damaged by tree roots. Therefore, most municipalities have guidelines on how close you can plant to utilities.
It's funny how often people overlook overhead utility lines, even though they are apparent. Planting large shade trees under or near these lines will eventually require the utility company to prune them to avoid conflict with the wires. Unfortunately, this type of pruning usually results in the tree being butchered into an unnatural appearance which shortens its life. Therefore, we are left with many one-sided trees in decline.
Planting tall trees near overhead lines can cause damage to lines during storms when trees contact wires. In addition, children climbing in trees adjacent to power lines can be severely injured or even killed if they encounter the cables.
HOW TO PLANT A TREE
· Dig a planting pit 2–3 times wider than the root ball but only deep enough to maintain the proper relationship of the root flare to the surrounding soil. The expression old landscape contractors used is, "Dig an ugly hole." Sometimes the side of the pit ends up slick from being cut with the steel of the shovel, especially in clay soils.
This condition can lead to the roots of the tree growing in a circular pattern inside the planting pit, leading to encircling roots that eventually strangle the tree. The sides of the planting pit should be roughed up with a shovel or pick. Make it rough and ugly.
· For ball and burlapped trees, remove all wrapping, twine, and plastics from the trunk and branches of the tree. Next, cut and remove as much of the wire basket and burlap as possible without damaging the root ball so it will not interfere with future root growth. With the burlap removed, closely inspect the tree root ball for circling roots and straighten or remove them with a set of loppers.
For container-grown trees, remove all wrapping, twine, and plastics. Remove the tree from the container by laying it on its side and pulling it from its rim. Do not lift it by the trunk to remove it. If the container won't budge, cut it with a utility knife and pull it off. Do thoroughly inspect the root ball for circling roots on container-grown trees. Unwrap, straighten, or remove encircling roots to ensure there are no problems in the future.
· The root flare is where the trunk widens at the tree's base. It must be partially visible after the tree is planted. Sometimes during shipping, a root ball will crumble inside the burlap and end up on top of the root flare. Remove the excess soil before planting to expose the root flare. Trees planted too deeply have their root flares buried, which invites insects and disease through bark that's not supposed to meet soil.
· When handling the tree, lift it by the root ball, not the trunk. Some root balls can weigh more than a ton, which puts an unnatural amount of stress on the roots and trunk that could kill them. The equivalent would be like a human being picked up by their neck while wearing lead boots.
· Place the tree in the hole, face the tree in the desired direction, and straighten. You'll want to walk around the tree and view it from several angles to ensure it's straight and true.
· Backfill in with 100% existing soil that's been broken up into 1" or smaller particles. The idea behind using the existing soil is to avoid the tree roots encircling the tree in the nutritious prepared backfill material as if it were growing in a pot. Pack soil in layers to prevent air pockets around the root ball. About halfway into backfilling, stop and water to collapse any air pockets. Continue backfilling until the soil in the hole is at the proper level.
· Avoid fertilizing at the time of planting. However, I like to spread an inch of compost mixed with worm castings from the root flare to approximately 2' outside the planting pit. This process will inoculate the planting medium with micro-organisms, trace elements beneficial to plant growth, and encourage tree roots to grow outside the planting pit.
· I understand that studies have shown that trees develop more robust trunks and roots if they are not staked, but they can also be set back or killed if they are blown over. So, I would rather stake a tree as a precaution but ensure they are removed after one year.
Stake trees at three points above ground. Underground systems are expensive but provide optimum support and aren't visible. The other advantage to underground staking is that there's nothing for people to trip or get caught up on. Stakes are required for a tree to grow upright when planting bare root stock or on windy sites.
· Mulch the base of the tree to cover the top of the root ball and planting pit. Place a 2–3" layer of mulch but be sure not to pile any right against the trunk. Maintaining a mulch-free area of 1–2 inches wide at the base of the tree will reduce the excess moisture on the bark to prevent decay.
· A homeowner can help maintain a tree's health by keeping a proper layer over its root ball while it's establishing. Mulch spread on a soil surface helps to moderate temperatures, maintain moisture and improve soil conditions, and help with weed control. However, a homeowner can overdo mulching and provide a poor environment to grow plants.
· Keep the soil around the root ball moist by watering deeply once or twice a week if nature doesn't provide a soaking rain. A tree planted in the spring should receive a deep watering until temperatures cool off in the fall, its first year. It is best to plant a tree in the fall and water it weekly during the summer and droughty periods for its first year.
AFTERCARE FOR TREES
When watering a tree, you want water long and slow to make sure it's getting down to the roots and saturating the surrounding area. For optimum health the first three years after planting, a tree should receive a deep watering a minimum of once per week during dry periods. First, lay the end of the garden hose near the edge of the planting pit and let it trickle until you see that the area is saturated. Then, move the hose around depending on the size of the tree.
Sprinkler systems do a good job watering planting beds and lawns, but an adequate amount for trees. Water gets sprayed on the trunk and leaves, creating ideal environments for fungal diseases. Trees and lawns have different watering needs. Check trees in irrigated lawn areas and give them additional water as needed.
The best way to check if a tree is receiving the proper amount of water is to check a couple of inches underneath the soil. It should be cool and moist but not wet. Here are some general guidelines for watering trees:
• 2″ caliper, water daily for two weeks, then weekly
• 2″ to 4″ caliper, water daily for one month, then weekly
• 4″ or larger, water daily for six weeks, then weekly
I must emphasize the importance of checking the soil moisture instead of just watering on a regular schedule. Allow the top two inches of the planting soil of a tree to dry out some between waterings. You don't want standing water or the soil to be always saturated.
Other than removing dead, diseased, or damaged branches, let the tree grow for one season before any corrective pruning. After that, the tree will need as much foliage as possible to recover from the digging and planting process.
After a year of post-planting, a tree is ready to be fertilized. At a minimum, a tree should receive a 10-10-10 fertilizer early in the spring. Apply as per manufacturer's specifications.
To keep a tree in tip-top condition, a top dressing of compost on its root zone. Applying an organic slow-release fertilizer in the early spring and early fall is ideal.
PAY ATTENTION TO YOUR TREES
The biggest killer of trees is that people forget about them. They become part of the scenery like a lamp post, but they are living things with needs. Keep an eye on your new trees and pay attention to see if anything unusual is happening. If you're paying attention, you begin to see seasonal patterns in your trees. For example, if your White Oak typically loses its leaves at the end of November, but it's starting to show fall color and dropping leaves in September, you know there's a problem.
Look out for insects and diseases during the establishment period because it is the most vulnerable period for a tree. A tree is still recovering from the stress of the transplant.
Eventually, a newly planted tree settles in a doesn't require so much attention. Maintain the fertilizing program and water during extreme heat and droughty conditions. Removing dead, damaged, and diseased limbs after storms and winter is the only thing needed to enjoy big shade trees for several lifetimes. It's one of the greatest gifts that we can give future generations and the planet.