Why Do My Trees Die? (Part 1)

In my 30 plus years of working in this industry and working with plants, if there is one thing that plants have taught me it’s that they don’t just die. There is always a cause. Sometimes Mother Nature whips up a storm which we are at the mercy of, in which case we obviously have no control over the outcome and the loss of plants. Most times however the burden of plant mortality falls at the hand of the landscape architect, landscape designer, installer and/or the landscape company that provides seasonal maintenance. 

In New Jersey we have a detrimental landscape process that has evolved into an epidemic and leads to the unfortunate and premature death of thousands of trees and shrubs every year. Whenever I present to a group of landscape professionals, I can’t believe that there is even a need for a conversation that revolves around the topic of proper planting and mulching.

In order to be successful and have plants that flourish we need to be cognizant of a plant’s culture. What does a plant want or need not to just survive for a one-to-five year period (note that the industry currently considers one year to be the standard guarantee for replacement), but thrive for generations? 

Before I go any further let me assure you, lest you think that after reading this I am a green industry hater – I’m not, to the contrary. I love the green industry, and after 30 plus years there is not one day that goes by that I have any regret or wish that I had taken another path as a career. I believe that we are all fortunate to be working in such a great industry with so many creative and hard working people that I know are passionate about what they do. We have opportunities to do awesome things, have positive impacts on the ecosystems we work in daily, and improve the overall health of our clients and employees. 

My intention is simply to make this industry a better place. From a consumer advocate perspective, we can and must do a better job at providing the public and the environment with better service. Trees and shrubs should not need to be replaced in 6 months, 1 or even 5 years. If sighted properly, culturally suited and planted at the proper depth, the common one year guarantee will be a thing of the past.

Problems at the Nursery Level

From the nursery supply side, right from the start of a tree’s life, nursery tree liners are planted too deeply. Rows are repeatedly tilled to keep weeds down, which in turn piles soil up onto the trunk and root collar of the trees and shrubs. (Tilling the rows is obviously better than applying herbicides – however, steps should be taken to remove this excess soil when the plants are dug). These two practices cause trees and shrubs to be dug with an excess of soil on top of the root ball. 

The root ball being buried in the nursery is only one part of this issue. The second part comes into play when a tree is dug mechanically by a tree spade. This scenario plays as follows: if you have an elevated grade around a tree (from improper planting or row tilling), then a tree spade will be digging too shallow. In this case, a portion of the root system is being cut and subsequently left behind underground in the nursery. If adjacent grades are correct when digging takes place, you would have a tree with a greater portion of the viable root system intact as opposed to being left behind. The tree would also be removed from the ground at the proper depth.

The next set of issues arise when the tree or shrub is balled and burlapped (B&B), brought to a wholesale or retail nursery and sold with the root flare buried with soil, covered in burlap, tied with nylon twine around the trunk and a diminished root system. Finally, you have a recipe for disaster once this plant is planted “as is” without removing any portion of the galvanized wire cages, burlap and twine.

The nursery issues explained above are then followed by the rampant inappropriate planting practices of trees and shrubs by low ball or just ill-informed landscape contractors as well as homeowners that are unaware of the issues mentioned previously. Homeowners are instructed by well-meaning but ill-informed local nurseries on how to plant. Whether a big box store or mom and pop local nursery, the misinformation is handed out one by one. One neighbor talks to another, and/or sees the property next door, municipal or business complex or strip mall, and assumes that all is right with that style of planting and mulching.

Problems with Conventional Planting

So many times when it comes to growing conditions, I hear professionals use terms like “tolerate” and “withstand” regarding sun, shade, wetness, etc., referring to a plant’s resilience toward certain conditions. What is left unsaid, however, is the increased likelihood of a plant’s need for pesticide applications and other maintenance services when planted among conditions bound to produce stress and a struggle for survival on the plant. For example, if one was to plant rhododendron or mt. laurel in a wet area, you would almost be certain to battle soil borne fungal pathogens like Phytophthora or Armillaria. We should instead change our approach from what a plant can merely “tolerate” to how well a plant can adapt. If a plant is fully adaptable to the conditions in which it is planted (granted it is properly planted), it should have a fairly long life and not succumb to stress.

This series of images illustrates a red maple installed into a landscape. This was planted by a sub-contracted landscaper by a builder in New Jersey, displaying how poorly some plants are raised and plantings are carried out. 

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Figure 1. From the onset it is obvious that this tree will more than likely be compromised due to poor quality plant selection and poor planting practices. Surface mulch and soil has already been removed to expose the marred trunk and the top portion of burlap.

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 Figure 2. A portion of the burlap is removed to expose the marred trunk – the darker (wet) area is where mulch and soil buried the trunk. Already the plant is approximately 3 inches below grade and no visible root flare also shows presence of twine and burlap.     

Note that this is not an isolated incident, but an issue we encounter almost daily. For every one of these conditions we see, I am sure there are thousands more under the mounds of mulch throughout the state.

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Figure 3. This shows just the beginning of the root flare. The point of the hand pruners show the location and the development of a major girdling root. The darker damp lower trunk area and root flare is 10-11 inches below grade. The final outcome here is that the plant was removed with a very much diminished, almost non-existent root system and final root collar/flare depth 12 inches. 

Container grown plants have similar issues as B&B plants.  They may also be planted in the container too deeply and have girdling roots. Container plants also have some unique issues, such as circling or diving roots, which are both exactly what they sound like: diving roots grow from the center of the plant and instead of growing outward they grow straight down. Circling roots will extend out from the plant in the container until they run into the side of the container or pot and begin circling the container. If planted like this the roots will stay in the form of the pot and encircle and constrict until the plant dies. With the lack of lateral root movement into native soil, the plant lacks anchoring and stability and will eventually topple over. 

Problems with Conventional Mulching

 

The detrimental practice of over mulching (AKA the “mulch volcano”) involves the excessive dumping of mulch over the root flare (the part of the trunk that ‘flares’ out into the root system) on the trunk of the plant, making trees and shrubs appear as if erupting from atop Mt. St. Helens. Somehow this has become a regular practice among conventional landscapers. Many issues arise when mulch covers the root flare, let alone a quarter of the trunk. Starving the roots of oxygen and essential vitamins from sunlight slowly kills the tree. Excess heat and moisture from mulch on the trunk or roots causes rot and susceptibility to other disease and pest issues. While mulch can provide useful organic matter, it must be kept away from the root flare.

I couldn’t point to one reason on how or why this practice of over mulching started. In short, my thoughts are that it started in the 1980’s when building and suburban development was moving at a fast pace. If a contractor realized that if a hole was only dug at ½ to ¾ of the appropriate depth, that would mean less labor cost. Then said contractor would follow that up by not having to remove any excess soil from the site because that is being used as backfill up against the portion of the root ball that remained exposed. Then the remainder of the root ball is covered with mulch. If you add the contractor mark up on mulch, then the more mulch you dump the more money in the pocket of the contractor. And finally, if a tree dies after a one year guarantee, the contractor gets paid again to remove and replace the dead plant with a new one. To some this may sound like a model for repeat business, but I don’t see it that way.  To me it is underhanded and unethical. The general public relies on so-called professionals to do the right thing. It is unfortunate that an unsuspecting consumer found this acceptable and bought into this idea.

Let’s talk about the ridiculous notion that trees and shrubs should be guaranteed for one year. (Perennial plants are a little bit of a different story as some can be a tad finicky and short lived in their nature. However, if all proper design and planting protocols are followed you should have great success with perennials also). You shouldn’t even need to guarantee a plant to begin with. If a plant is dug, planted properly in a culturally appropriate place and not over mulched, a plant will thrive. The idea that it is acceptable for a plant to die in a landscape only after one year of installation is ludicrous. So, we (our company – McCoy Horticultural) take this plant guarantee notion a step further only because people ask for a guarantee. We offer a three-year guarantee which is still senseless. I would guarantee that our trees will live beyond a 5, 10 or 15 year guarantee. It’s plain and simple due to the steps we take before, as we plant, and the proper follow-up care given our plants do not die.

By Richard A. McCoy