It is tough being a tree growing on the Front Range of Colorado. Drought, poor soils, extreme temperature swings, leaf shredding hail, and branch snapping winds are all challenges that we face trying to grow healthy trees to maturity. Newly planted trees have it extra tough. Ball and burlap nursery trees have lost up to 90% of their root system during transplant, and need to regrow a healthy root system before they are able to grow effectively in other ways.
Ensuring proper depth at planting, maintaining appropriate soil moisture, installing a mulch ring, protecting the trunk from sunscald, and consulting with your local arborist are all things that you can do for your newly planted tree that are low-cost and minimal time investment. These are things that can make or break a new tree in its first five years following transplant, so let’s take a look at each item.
Correct Depth for Newly Planted Trees
One of the biggest mistakes that landscapers and homeowners make with newly planted trees is to plant them too deep. The root flare needs to be at, or slightly above grade. To find the root flare of a tree, excess soil typically needs to be removed from the top of the root ball before determining the depth of the planting hole. Before planting a tree yourself, or before having a landscaper plant, please check out CSU’s document The Science of Planting Trees for great info on how to properly plant a tree.
Trees require certain levels of oxygen to be in the soil for roots to grow (or regrow in the case of new transplants). As you move down in the soil profile, oxygen levels decrease quickly, especially in high clay content soil. Tree roots of a tree planted too deeply are likely not going to receive enough oxygen to regrow properly. This problem is made worse by overwatering, or if there are broken irrigation lines near the tree.
Planting too deep can also result in other issues, such as stem girdling roots and root collar rot diseases infecting the base of the tree. Symptoms of these issues usually do not show up until 5-10 years after the tree has been transplanted, but can seldom be corrected once the symptoms show up, and may result in the premature death of your new tree.
Maintaining Appropriate Soil Moisture
If planting too deep is the single biggest mistake made during planting, not maintaining appropriate soil moisture is the biggest mistake made after planting. New trees require consistent moisture through the growing season, but not so much that oxygen levels get depleted. Our soils here tend to be high in clay, which can cause them to drain poorly. Water from irrigation can get trapped in the planting hole, creating an anaerobic situation where roots are unable to grow. If roots can’t grow, the tree can’t grow, and can die within a year or two if the situation is not remedied.
Not watering enough can also be a problem, especially during very hot, dry, and windy periods in mid to late summer. For evergreens, late winter to early spring is also a time when additional water is needed to prevent damage. It is highly recommended that any new tree installs be incorporated into your properties automatic irrigation system to prevent forgetting to water during crucial times. Well intentioned homeowners that swear that they will water by hand diligently commonly come home to a dead tree after a two week summer vacation.
Not sure if you are keeping the soil moisture around the base of your newly planted tree at correct levels? Dig in there and check it out! Use a small garden trowel or soil probe to carefully dig down 6-12 inches and inspect the soil. If you can squeeze water out of the soil with your hand, it is too wet. If it doesn’t clump at all and falls apart after a squeeze, it’s too dry. If it forms a clump in your hand that sticks together, it’s within an acceptable range. For more information about proper watering, check out CSU Extensions document Caring for Newly Planted Trees.
Install a Mulch Ring
Nope, not rocks. Not the rubber stuff. And please, no turf either. The best material to put on the ground around (but not up against!) your new tree is wood chips from your locally owned and operated tree service. And ditch the landscape fabric. These materials disrupt water and gas exchange between the air and soil, and can suffocate tree roots.
Installing a mulch ring of wood chips at a 3-4 inch deep layer and at least 4-6 inches from the base of the tree helps retain soil moisture (less evaporation), moderates soil temperatures, keeps weed whackers and mowers away, suppresses weed growth, and improves soil quality as it breaks down.
Protect the Bark of Newly Planted Trees
If you have lived in Colorado for a while, you have likely experienced a spring day that involved waking up to 6 inches of snow. Then the sun comes out, and temperatures rise to 50, 60, or 70 degrees. Then it’s back down into the teens that night. These extreme swings in temperature, combined with intense solar radiation being reflected back up from the snow surface can cause significant damage to new planted trees with thin bark, called sunscald.
This results in the death of cambium cells, especially on the south and west sides of the trunk (also called southwest injury), near the base and extending upwards. This type of damage is most common with thin barked species such as maples, linden, fruit trees, and honeylocust, but can happen to any species when they are young and have not developed mature bark yet. If the bark is still smooth, it is most likely susceptible to sunscald. Sunscald can also occur on newer, younger branches of mature trees, especially after heavy pruning that can expose branches to direct sunlight that otherwise were protected before the pruning.
Wrapping tree trunks with a product such as Jobe’s Tree Wrap will help protect newly planted tree trunks from sunscald damage. Wrap the tree in November and take the wrap off in May after the last freeze. Do this for the first 5 or so years post planting. I like this product in particular because it’s white (white reflects solar radiation the best), it’s porous (allowing gas exchange for the trunk), and it’s relatively inexpensive.
Consult With Your Local Arborist
No, not the family friend that worked for a tree company for a summer 20 years ago. An actual arborist. An individual who has spent their professional career working with trees and tree owners to achieve favorable results for both. At Patriot Tree Company, we currently have 4 ISA Certified Arborists and 1 ISA Board Certified Master Arborist on staff, any of whom are available for personalized consultation sessions. An hour consultation may cost up to $120 (with our BCMA), but considering the cost of planting new trees, this is a worthwhile investment (in our humble opinion).
In conjunction with proper planting depth, watering, mulching, and trunk wrap, a once per year root building treatment is recommended for most new tree plantings. We use BioRush Plus for this application due to its high potassium content (root stimulating macro nutrient), beneficial microbes, humic acid, and chelated iron. This is recommended for the first 4-5 years post planting.
Please give us a call if you have any questions regarding root building treatments, arborist consultations, or the content of this blog post. Until next time, keep off the ladder and leave the tree climbing to us. Broken bones and damaged property are more expensive (and painful) than professional tree services. Cheers!