Improper tree planting is without a doubt the main reason for the decline and death of trees. And the #1 mistake that causes the most problems in the Improper Tree Planting category is . . .
. . . "WHAT, are the roots being planted too deep into the ground, Alex?" Winner winner chicken dinner.
Upwards of 80 percent of all tree problems can be attributed to their soil environment. And just so everyone understands---planting trees too deep in the soil is a soil environment issue.
To make matters worse there seems to be a major epidemic of this going on. Everywhere you look you find the problem. You don't have to look hard. Actually you have to look hard to find trees that have been properly planted. There are a couple severe issues that affect trees when the roots are in the ground too deep. One is that there is less oxygen the deeper down you go. Trees are genetically set up to function best when their roots have a specific amount of oxygen. When that amount of oxygen is denied the roots don't function at optimum levels and when roots suffer the entire tree suffers. As The Roots Go, So Go The Shoots. Often the roots will try to grow upwards where there is more oxygen. This creates a whole new set of problems.
Trees don't adapt well enough to survive this problem. Many will die within a couple of years, some will survive but will be stressed and unhealthy forever and will need greater care forever just to keep them alive. When soil is piled against a tree trunk it is constantly in a moist environment and that creates more issues. Trunk tissue is not adapted to excessive moisture---when it's constantly wet it provides an environment conducive to cooties that can destroy vascular tissue. And that tissue is pretty important stuff. Some trees will try to adapt by sending out adventitious roots from buried bark tissue (See photo below). These roots lose normal outward orientation and wrap around the main stem, thus called "girdling roots." Just look at a few pictures and it will be obvious that this is bad for the tree. Roots growing upward looking for some air.
So, why do we have this epidemic? Well, many in the green industry have a tendency to blame "landscapers" (you arborists know who I'm talking about). But I believe it is a multitude of reasons. First, deep or buried roots are often referred to as "planting too deep." This is not always caused by the planting process.
The entire growing and harvesting process methods contribute to the epidemic. Cultivating practices have a tendency to throw soil up around trees growing in fields and with the propensity of mechanical harvesting the problem does not get corrected. Back in the day of hand digging this was not a big problem. And simple economics plays a role. There is a big push to get the trees out of the nursery. Container-grown plants have their own issues. As a tree makes its way from nursery pot to liner and finally to the landscape there is an opportunity for planting deeper in the ground. Now I agree that some landscape contractors are planting incorrectly but they are not alone. I imagine homeowners are the worst culprits. Most are clueless and don't get good information when buying the tree. I saw a company website that told people "YOU CAN NEVER PLANT TOO HIGH." Real good information there.
They should put warning labels on trees about planting too deep. Every other item you buy has warning labels to save themselves from being sued. Before you know it we will have a whole new crop of schiesters coming after us for killing trees. Don't laugh.
But, the number of trees planted by homeowners compared to "landscapers" (I hate that term) is just a small fraction. Yes, the landscape industry needs to get its professional act together, I have said that many many times. But this is an industry wide problem---propagators, growers, landscape architects, arborists, municipal foresters and contractors. The problem is worsened by the presence of a conflict of interest that exists among industries. Cross-discipline communication and respect needs to be increased for the benefit of all of us.
So, let's get back to improper tree planting because there is more involved than just "planting too deep." How about the shape and size of the hole in the ground---isn't it important also? Oh heck yes it is. I see holes way too small and shaped wrong more often than too deep. Too often the hole is just big enough to stuff the rootball in and the rootball is already kissing the rock hard existing soil. The hole should be wide (2 to 3 times the width of the rootball) with very sloped sides. See photos for good and bad holes. Planting hole width is the key to promoting rapid root growth, reducing post-planting stress. If roots have difficulty penetrating compacted site soil (due to low soil oxygen levels), sloped sides direct roots upward and outward toward the higher oxygen soil near the surface rather than being trapped in the planting hole. Poor drainage situations need to be mentioned because poorly drained and compacted soils typical of modern housing developments is prevalant and more trees die from too much water than from not enough. See picture for planting in poorly drained soils.
One other issue that arises during planting that inevitably turns into a problem for trees is the "Mulch Ring." Improper mulching is often the culprit behind girdling roots. The norm is that it is too deep and piled against the trunk. Too much mulch acts the same way as planting too deep. You get less oxygen getting to the roots and to compensate they grow up and eventually around the trunk. Mulch against the trunk is the same as soil against the trunk plus you add the possibility of small rodents hanging out in the thick mulch nibbling on the bark. It seems that absolutely no one mulches correctly. Of course many people do, but you see so many incorrectly mulched trees that's what you are led to believe.
When you do see one done correctly it's like you have spotted a sasquatch. It makes you wonder if eliminating the practice of mulch tree rings should be eliminated. Oh, I can hear the gasps all the way through these pages.
But I bet we would save thousands of trees that would have perished if they had been mulched the usual way. I have read quite a bit from credible professionals that have good arguments in favor of eliminating mulch tree rings. Let's look at some facts. For newly planted trees mulch does have some benefits, mainly putting organic matter into the soil and keeping completion down from weeds and turf.
Research has also shown that you can use an herbicide to keep the weeds and turf at bay and you get the same effects, with bare soil, on the tree's establishment as with using a mulch ring.
I also hear people say that it helps keep moisture in the rootball---that's not entirely true, since upwards of 90% of moisture is lost from the rootball from transpiration---only 1% is lost through evaporation.
So, once a tree gets established we lose much of mulch's beneficial effects. Those little baby mulch rings you see around established trees are not really benefitting the tree for anything except stopping damage from mowers and weed whips. To get benefits for the feeder roots from mulch you would need to have a ring at least out to the drip line, which is where the feeder roots are. There is very little feeder root activity up close to the trunk. And we will never see tree rings that big because people love their lawns too much. You might say "at least they are trying" but when their attempts are hurting a tree why try at all.
I do want to mention one more issue that is a tree problem and it is these "Tree Necklaces." I don't really think trees are into the bling thing. You figure most of these necklaces are added after the tree has been planted, so obviously they have piled soil higher on the rootball and against the trunk. And we know what happens after that. Now that's what I'm talking about. BLING BLING. Some people sure spend a lot of money to kill their trees---a senseless waste.
Some of the issues I discussed you may not agree with and that's OK. We need good discussion within the industry. All we can do is go out there and try to do our best and keep up with all the new research and information--- because it comes at a rapid-fire pace.