40 Years of Tree Work and PHC – Part 2: Programs, Treatments and Fertilizers

The composite depicting various PHC practices is courtesy of Randy Cyr, operator of Greentree, a consulting arborist company based in Greenville, South Carolina, and a former TCIA member.

This is the second of a three-part series by the author. Part 1, “Musings on Tree Work and Plant Health Care After 40 Years in the Industry,” (TCI, October 2020) covered his getting into the industry, the importance of mentors and the education and training needed for a career in PHC.

In this article, we’ll look at schools of thought on plant health care (PHC) programs and get into sick trees and plants as well as fertilizing.

A plant-health-care program revolves around individual trees and plants. It is the true doctoring of plants. The primary goal is to keep trees and plants alive and healthy. You deal with insects, diseases, soil issues, weather – including cold, heat, drought, lightning and excessive rain – construction/development issues, salt, air-pollution issues and anything else that could contribute to plant decline.

Schools of thought on PHC programs

There is an old saying, “There is more than one way to skin a cat!” Similarly, there are a number of schools of thought on PHC.

Assume you have arranged an appointment at your client’s home and have inspected and determined the tree/plant problem. Here are some sales options:

• Sell a takedown because you are old school and takedowns are all you know.

• Sell a job while there to specifically treat the tree or trees and plants for insect, disease, mineral deficiencies, construction problems, etc., both visible and those the client pointed out to you, and think no further.

• Sell a contract to solve the tree/plant problem and then sell a separate contract for a specific price-per-visit to the property on a monthly basis for inspection of plants, with a clause that enables you to give an additional cost of specific treatment for a plant if a problem is encountered during the season or the length of the contract.

• Set up a “preventative” treatment program for the year with “x” number of sprays, injections, soil drenches, etc., planned in advance, whether there is a problem or not.

• Numerous variations on the last two options.

There is merit to the last two methods. When I started Cortese Tree Specialists in March of 1977, I did what I had to do to stay alive. I did tree and shrub pruning, and I looked for opportunities to treat trees when the opportunity arose. I did not sell contracts for PHC programs. I sold individual treatments. Later, after traveling around the southern U.S. for a number of years, I started setting up annual aphid, tent-caterpillar and fertilizer treatments. At some point, I started analyzing the clients’ properties, doing an inventory of what trees and shrubs were there, and then figured out what major potential insect, leaf-fungus or other problems might be an issue.

I factored in the potential cost of treatments if these issues became manifest. I divided the cost of all these potential treatments by the number of visits. I then proposed to the client a PHC contract. If the problems I projected arose, I was covered. If they didn’t, I was more profitable.

Then there is the determination of the major plant-health-care problems in your specific area. Take Dutch elm disease, for example. What is your policy and treatment for this problem when you or your other arborists come in contact with this at a client’s home? What about elm phloem necrosis? What about sycamore anthracnose, dogwood borers, emerald ash borers, inchworms, bagworms, tent caterpillars, construction-site tree damage, lightning strikes? It is important to have a plan before the problem is found in the client’s yard. Sometimes you will get to a client’s property, inspect their trees and tell them nothing can be done right now because it is not the right time of year for the application, and that the treatment needs to be done in the spring just prior to, during or after leaf expansion. This builds credibility for you and your company.

One of my first annual treatment sales was precipitated by a phone call received on my answering machine in the early 1980s. I came in from pruning a tree in the late afternoon and listened to the calls on the answering machine. “This is C. K. Morris, emergency! I’m at blank, blank road. I am at 865-363… Emergency! EEEEEEMerrrrrrrrgency!”

I got to C.K.’s place, and his emergency was mature tent caterpillars that had defoliated the 10 large black-cherry trees, Prunus serotina, in his yard and were migrating toward his house, and eaves, to pupate. There were thousands of 2-inch-long caterpillars everywhere. I returned soon with a load of Sevin insecticide and sprayed everywhere I could. By golly, I took a shower in the spray. However, I got C.K.’s problem solved, and every year for the next 10 years, I injected his trees when I saw the webs in the trees at a quarter to half-dollar size. He was the most grateful client I ever knew, and he became a very good friend.

Your PHC program will evolve. The tools, techniques and products today are much superior to 1977. Modern treatments include soil sampling, air-tool treatments, mycorrhizae, biologically activated carbon or bio-char and organic materials such as humates and kelps. Today, there is much greater emphasis on soil treatments to improve root development, as opposed to just throwing nitrogen fertilizer over the tree’s root zone; the effort to mimic the natural root zone of the forest is the ideal. The introduction of predator insects to feed on the bad ones and the use of pheromones to attract the bad bugs is on the rise. There are new insecticides that are organic, such as BioForest’s TreeAzin that disrupts an insect’s fertility.

Your PHC program will evolve. Modern treatments include soil sampling, air-tool treatments, mycorrhizae, biologically activated carbon or bio-char and organic materials such as humates and kelps. Graphics courtesy of the author, unless otherwise noted.

Tree growth regulators (TGRs) such as fourth-generation Short Stop redirect a tree’s energy, inhibiting shoot elongation and building up root development. Leaves are usually a third to a half their normal size, and the leaf cuticles are much thicker with concentrated chlorophyll. It is my opinion that growth regulators are in their infancy in PHC programs. They can be used for regulation of tree height under power lines, to protect and treat trees in construction sites or to treat trees after construction damage is done. They can be used for treating shrubbery and to improve tree and plant survivability during transplanting. They can be used for treating crown-reduced trees in scenic views. They can be used to extend the lives of unsold trees in nurseries.

I theorize that TGRs could be used in conjunction with disease and insect control. The thicker cuticle they produce should be harder for aphids to insert their proboscises into to suck the juices out, and harder as well for fungal organisms to penetrate and get a foothold. Of course, this will require research to make a final determination.

Today, we have an understanding of degree days that helps us pinpoint exactly when to treat trees for most effective insect control. Most of the professional companies selling PHC programs are more sophisticated in their approaches today. The days of coming in and spraying all the trees with DDT or other equally bad insecticides on a monthly basis are over. Thank goodness! It is my hope that the same will come to pass with the overuse of nitrogen fertilizers and herbicides.

Regardless of how you plan your PHC program, there is a lot more research to access today. There are constant improvements in tools and techniques and in the understanding of treatment timings and tree biology.

Sick trees and plants

PHC starts with being able to identify the species of plant you are looking at. If you cannot identify the plant, it is a pretty sure bet you will not be able to figure out what the matter is.

PHC programs start with a client having sick plants. PHC starts with being able to identify the species of plant you are looking at. Hundreds of potential insect and disease problems are in the client’s yard. If you cannot identify the plant, it is a pretty sure bet you will not be able to figure out what the matter is. Tree insects and diseases are generally species specific. For example, with a black cherry, weeping cherry or Kwanzan cherry, or any plant in the Rosaceae family, which includes apple trees, you can project the potential for tent caterpillars during late March through April. You can sell that job now to be performed at the proper time next spring. What if you see a hemlock? Well, you can inspect it for hemlock woolly adelgid, scale and spider mites, then sell treatment for the most advantageous time frame for achieving control.

There is a very distinct correlation between species of tree, soils they grow in, soil pH and associated fungi, insects and diseases that are specific to them. You must study intensely to get a handle on tree-species identification and what will attack them.

You have to know what a healthy tree looks like in order to know what a sick tree looks like. As Dr. Al Shigo said, “To know trees, you have to touch trees!”

TCIA and ISA have wonderful collections of books to use as resources. Some of my favorites are P.P. Pirone’s Diseases and Pests of Ornamental Plants, Sinclair, Johnson and Lyon’s Diseases of Trees and Shrubs and Johnson and Lyon’s Insects of Trees and Shrubs. There are many tree-identification books available. Check with your state agricultural extension service, the state division of forestry, online stores and your local library.

Fertilizers and fertilizing?

Fertilizing trees and plants is more complex than most people want to recognize. There has been, and continues to be, an evolution and revolution of tree fertilizers and their relationship to the tree.

Fertilizing trees and plants is more complex than most people want to recognize. In the ’70s, there were basically three methods: 1) Go to the hardware store/co-op and buy a bag of 10-10-10 fertilizer and put it in a bucket. Reach into the bucket as you walk over the yard and broadcast the fertilizer over the tree/plant-root zone; 2) Buy the same bag of 10-10-10 and get your bucket and a 3- to 4-foot, one-and-a-half-inch-diameter rod (referred to by some as a “dummy bar”). Take a hammer and bang the bar into the ground 8 to 12 inches, then pour your fertilizer into the hole. Do this in an approximately 3-foot grid over the root zone. 3) If you are really progressive, you will have your handy Bean sprayer. Take the bag of 10-10-10, fill your 200-gallon tank with water, pour in your fertilizer and stir it up. Then go out to the client’s yard and pump the fertilizer into the root-zone area of the tree on a 3-foot grid.

Today, your options have expanded. You can use a high-pressure air tool to make long trenches in the root zone of a tree and mix in amendments such as mycorrhizae, kelps, humates and other organic and traditional fertilizers, and then call each of these methods vertical mulching or soil therapy. You can even find liquid fertilizers that can be applied as a bark treatment; they move through the lenticels of the bark. Then there is a new kid on the block, biologically activated Vital Blend biochar or other brands of carbon for putting around trees in addition to mulch or compost, or for incorporating into mulch or compost and then spraying with humates to activate the carbon.

Dr. Shigo launched a revolution in our industry. It is not only in tree biology, the equipment that we use to prune and climb the tree or the evolution of chemicals we use to treat trees. It is also in the study of tree roots, where they are and what will improve their biosphere and overall health. It is a fact that one can grow a tree to death with fertilizers. It is also a fact that you can kill a tree with fertilizer if there is phytophthora in the tree’s root zone. There has been, and continues to be, an evolution and revolution of tree fertilizers and their relationship to the tree. Some questions to ponder include:

• Do you know what the pH is in the soil around your client’s tree? This helps determine what type of fertilizer/soil amendments the tree needs. It is the starting point.

• Do you want to use powdered fertilizer that mixes into water in a 100- or 200-gallon tank and pump, or do you want to use a liquid fertilizer mixed into a tank and pump? Utilizing powders always leaves residue in the tanks. In addition, most powders wear down the bearings in the pumps, shortening pump life.

• Do you want to purchase a pre-mixed dry or liquid fertilizer, or do you want to create your own? Do you want your fertilizer to be “organic” or something else? What about compost teas, mulches and earthworms, earthworm casts and other biologicals?

• Do you want to use your air tool to create channels around the tree and replace soil with a special organic/mycorrhizal fertilizer blend?

Then there is the American BioChar system of reducing fertilizer use by up to 75%. This involves pumping organic fertilizer such as Nature Pro’s Bio Tree & Shrub with humates, kelps and other bio-organisms into the root-plate area, or into a targeted root-zone area within two or three feet of the tree’s trunk, instead of over the entire root zone. The idea is that there are massive quantities of tree roots and root hairs that can take up the fertilizer in this significantly reduced area, thus less runoff potential and less fertilizer (30-50%) used to get similar or better results than traditional fertilizing. Many more trees can be fertilized in the time it would take to perform traditional fertilization, and it saves money, so in my estimation it is good conservation.

The bottom line is, there are many brands of fertilizers and methods of working with the root systems of trees that ultimately translate into improving a tree’s health. There is much research needed and many miles to go before we have an overall understanding of soils, the roots of trees and the best ways to improve tree health.

Treating trees and plants

There are many ways to treat plants for insects and diseases: over-the-top and aerial sprays, broadcasts, trunk injectables, trunk-bark sprays, soil injections and drenches, use of traps and pheromones to monitor insects, biologicals, organics, predator insects and more.

There are many ways to treat plants for insects and diseases: over-the-top and aerial sprays, broadcasts, trunk injectables, trunk-bark sprays, soil injections and drenches, use of traps and pheromones to monitor insects, biologicals, organics and predator insects, etc.

One should not be wed to one specific brand/line of products or systems. I believe the efficacy of products is generally very good for most brands, and they do what their labels say they do. However, there are pros and cons for all products to be considered for specific disease, insect and mineral problems. For example, Tree Tech Injections has a product, Systrex, that is the only combination fertilizer/fungicide available. They also have Snipper, a fruit-drop product, as an injectable. Mauget’s Fungisol is a warhorse product with more than 30 diseases on its label. It has been doing its job since the early 1970s, and is the only benamyl derivative not owned by the DuPont Corporation. Imidacloprid has been a go-to treatment for controlling many insects for years now. However, there are now potential bee problems showing up. Its future is looking troubling and uncertain. Bark-spray treatments of Valent’s Safari is a wonderful option for insect control, as are bark treatments of permethrin.

For control of EAB, there are Arborjet’s TreeAge and TreeAge G4, restricted- and non-restricted-use products with a two-year control; or BioForest’s Ecoject system with TreeAzin, an organic product that also has a two-year residual. There is ArborSystem’s Wedgle; if you have mass quantities of trees to treat, it is far and away the quickest, most labor-saving tool available. It is possible to treat seven ash trees with this method in the time it takes you to treat one tree with other methods.

A technician excavates a tree’s root zone with an air tool to mitigate soil compaction prior to applying soil amendments. Photo courtesy of Kelby Fite, Ph.D., Bartlett Tree Research Lab.

For those who wish to visit the client’s property each year, you can use Mauget’s Imicide, Tree Techs Merit or Valent’s Safari as a bark spray or soil drench. Then there is the cheapest method of treatment – generic imidacloprid as a soil drench. You can get Rainbow Tree Scientific’s Xytect brand, which has a double rate; this is a really great, inexpensive way to treat ash trees larger than 22-inch dbh.

There is so much change happening in the industry, but you now have more options and possibilities, and more safety, than at any time in history. Reading, studying and keeping up with what is available in the market is absolutely a necessity!

The third and final installment of this series, scheduled to run in the January 2021 issue of TCI, will discuss the business of PHC, including record keeping sales and marketing.

Jim Cortese is an ISA Board Certified Master Arborist (BCMA), a member of the American Society of Consulting Arborists (ASCA), president and CEO of Jim Cortese Consulting Arborist, a 40-year TCIA member company based in Knoxville, Tennessee, and president, CEO and the major stockholder of
TIPCO (Tree Injection Products Company), Inc., a seven-year TCIA Corporate Member company, also based in Knoxville. He started both TIPCO, a distributor of plant-health-care products nationwide, and Cortese Tree Specialists, Inc., in 1977. Cortese Tree Specialists had an average of 15 full-time employees for the 35 years prior to its sale to The Davey Tree Expert Company in 2013.

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