Plant health care (PHC) field guide for trees and shrubs

Plant health care, and why most decline starts in the soil

Plant health care, PHC for short, is a proactive program that keeps trees and shrubs healthy from the roots up rather than reacting to dead plants. You manage the growing conditions first, the soil, the roots, the water, and the nutrition, you monitor for stress on a schedule, and you treat problems while they are still small. Pest and disease control is part of the work. It is one tool, not the whole job.

Most people get the cause backward. When a landscape plant looks bad, the reflex is to hunt for a bug or a fungus. On most jobs the real trouble was already in the ground before any pest showed up: soil packed hard by foot traffic and equipment, a tree set too deep so the trunk is buried, a rootball nobody watered through its first dry summer, or a cone of mulch piled against the bark. Those are abiotic problems, the non-living kind, and they account for most of the decline a crew gets called out to look at.

So PHC starts where the trouble starts, at the soil and the roots, and folds in integrated pest management as the pest and disease piece. Getting a new plant in the ground at the right depth is its own job and lives in the tree and shrub planting guide. The pest, disease, and weed control side lives in the landscape IPM guide. This is the proactive program that ties the rest together and keeps a healthy plant healthy.

Why proactive beats replacing dead plants

A healthy plant defends itself. A tree with room for its roots, the right water, and a balanced soil shrugs off the borer, the leaf spot, and the dry August that would kill a stressed neighbor next to it. That is the whole argument for spending money on conditions instead of on symptoms. You are not buying a cure. You are buying the plant's own resistance.

The math favors the proactive side because of what a mature plant is worth. A 30-year-old shade tree is not a line item you re-buy at the nursery. Replacing it costs years you cannot purchase, plus the removal, the stump, and the new install that will not match it for a decade. Catching the decline early and correcting the soil and the water is cheap against that loss, and it is the difference between a property that holds its canopy and one that thins out a tree at a time.

Proactive care also changes the business. A recurring program of scheduled visits, soil work, feeding to need, and monitoring is steady revenue and fewer emergencies than a one-off call to look at something already half dead. Reacting to dead plants is the most expensive way to run this trade, for the client and for the crew.

What is the difference between PHC and IPM?

PHC is the whole proactive program. IPM is the pest, disease, and weed control part inside it. The International Society of Arboriculture coined plant health care to put IPM techniques into a wider frame, so PHC does not replace IPM. It contains it. IPM becomes one of the strategies PHC uses, not the strategy.

The split comes down to what you are managing. IPM manages a pest: identify it, monitor it, set a threshold, treat with the least-risk option that works. PHC manages the plant: the soil, the roots, the water, the nutrition, the structure, and the site, with pest control as one move among many. A client buys a PHC program to keep a landscape looking good and living long, not to kill a specific insect.

On the ground the difference is order of operations. PHC asks why the plant is stressed and fixes the condition, which often removes the reason the pest could get a foothold at all. IPM handles the pest once it is there. Run them together: the monitoring that feeds your IPM decisions is the same monitoring that drives the whole PHC program. The full pest and disease decision process is in the landscape IPM guide, so this guide does not repeat it.

Why is my plant declining when I can't find a pest?

Because most landscape decline is abiotic, the non-living kind, and it does not leave an organism to find. Before you reach for a spray, sort the cause into living or not living, and look at the abiotic list first, because that is where the answer usually is.

The abiotic causes that kill the most plants are compacted soil, planting too deep with the root flare buried, drought stress in dry spells, the opposite problem of soil kept too wet, a mulch volcano packed against the trunk, root damage from digging or string trimmers, and de-icing salt along roads and walks. None of those is a bug. All of them weaken the plant slowly, and a weak plant is exactly what an insect or a disease moves in on next.

There is a tell that separates the two. An abiotic problem usually matches a feature of the site: it follows the compacted path, the dry corner the irrigation misses, the strip where the plow piles salt, or the exact line where the grade was raised. A biotic problem tends to spread over time and you can often find the organism. When the damage maps to the site instead of spreading, stop looking for a pest and look at the conditions. The fix is in the ground, not in the tank.

It starts at the roots

Most plant problems are root and soil problems wearing a different face up top. The canopy is what the client sees, but the roots are what is failing first, and by the time the crown thins or the leaves scorch, the roots have usually been in trouble for a season or more. Look down before you look up.

A few things about roots that change how you treat a plant. They are shallow. The fine feeder roots that take up most of the water and nutrients live in the top 6 to 18 inches of soil, not deep down where people imagine them, and they spread well past the dripline, often as far as the canopy is tall. That whole area is the critical root zone, the soil volume the tree depends on, and protecting it is most of the job. The root flare, where the trunk widens into the first main roots, has to be at the surface and visible. Bury it and the bark sits wet and suffocates.

Then there is the slow killer: girdling roots. A root that circles the trunk instead of growing outward, often from a pot the plant outgrew or from soil and mulch piled against the stem, thickens over years until it strangles the trunk and chokes off the flow of water and food. By the time the canopy shows it, the damage is usually permanent. Find it early by exposing the flare and looking for roots that cross or wrap, and you can sometimes cut the offender before it closes off.

The soil is the foundation of plant health

Everything else in a PHC program rides on the soil, so that is where the assessment starts. Three things matter most: the physical structure, the chemistry, and the biology. Structure is whether the soil has pore space for air and water or has been crushed solid. Chemistry is the pH and the available nutrients. Biology is the organic matter and the living organisms that cycle those nutrients into a form roots can use.

Urban and suburban landscape soil is usually a poor version of all three. It is graded, stripped of topsoil, mixed with construction fill, compacted by equipment, and short on organic matter. Roots cannot push through it, water either runs off or sits, and the nutrients that are present are often locked up by a pH that swung off range when the subsoil and the concrete leached into it. A plant set into that is fighting the ground from day one.

The proactive fixes are the cheap ones, and they work on conditions instead of symptoms. Build organic matter with mulch and compost over the root zone. Relieve compaction so roots and water can move. Match the plant to the pH the site actually has, or amend toward it slowly. Most of plant health is just giving the roots a soil they can live in. Get the planting right at install, covered in the tree and shrub planting guide, and the soil work afterward has a head start.

Do you need a soil test before fertilizing?

Yes. Test the soil before you feed, because guessing the fertility is how plants get the wrong nutrient, the wrong amount, or a dose they did not need at all. A soil test reads the pH and the available nutrients and tells you what is actually short, so you treat the deficiency the plant has rather than the one the bag assumes.

Send the sample to a real lab, usually the state land-grant university soil lab or your cooperative extension, not a meter probe from the store. Pull several small cores from the root zone, mix them into one representative sample, and tell the lab it is for trees and shrubs so the recommendation fits. The fee is small against the cost of fertilizing blind for years.

The pH result is the one people skip and the one that controls the rest. When the pH is off range for the species, nutrients that are present in the soil are chemically locked up and the roots cannot take them, so adding more fertilizer does nothing but cost money and load the soil with salts. A common example is iron chlorosis, the yellowing between leaf veins on pin oaks and other acid-loving plants growing in soil that is too alkaline. The iron is there. The pH has made it unavailable. You fix the pH and the availability, not just the iron, and a certified arborist sizes that correction to the test and the species.

Soil compaction, the number one urban tree stressor

Compaction is the most common thing wrong with the soil under a stressed urban tree, and it is a silent killer because it shows up as slow decline years after the soil got crushed. When foot traffic, parking, mowers, and construction equipment pack the soil solid, they squeeze out the pore space roots need for air and water. Roots suffocate, water cannot infiltrate, and the tree thins from the top down with no pest in sight.

You confirm it the simple way: a soil probe or a screwdriver that you can push into healthy bed soil will stop hard in compacted ground. Match that to the site and the story usually writes itself, the worst compaction under the path, the parking edge, or wherever the equipment sat.

Relieving it on an established tree is its own set of methods, and the rates and patterns belong to a certified arborist. The cleanest tool is the air spade, a pneumatic lance that blasts soil loose with compressed air without cutting the roots the way a shovel or auger would. Radial trenching cuts narrow spokes out from the trunk and backfills them with loosened, amended soil to give roots a path, and replacing root-zone soil this way has been shown to lift fine-root density sharply. Vertical mulching drills a grid of holes and fills them with an amendment to open the profile. The one move you do not make is rototilling under a tree, which shreds the very roots you are trying to help.

Prevention beats all of it. Keep equipment and traffic off the root zone, and where people will walk, spread wood chips or build a path rather than letting the bare soil pack down.

How deep is too deep, and the buried root flare

Planting too deep is the slow, common killer, and it works by burying the root flare. The flare is the point where the trunk widens into the first main roots, and it belongs at or just above the surface. Set it below grade, or let soil and mulch creep over it, and the bark that was built to be in open air sits wet and starved of oxygen until it rots, while the roots above the original ball turn into girdling roots. The plant can take years to die, which is why nobody connects the death to the planting.

On a tree that is already in the ground, the test is to find the flare. If you walk up to a tree and the trunk goes straight into the soil like a telephone pole, with no visible flare or buttress roots, it is planted or buried too deep. A tree should look like it has feet. When it looks like a post driven into the ground, the flare is buried.

The correction is to expose the flare, carefully removing the excess soil and mulch off the top of the root zone until the first structural roots and the trunk flare are open to the air, then cutting any girdling roots a certified arborist judges safe to remove. Getting depth right at install is the cheaper path, and that whole job, finding the flare and setting it at grade, is covered in the tree and shrub planting guide.

Mulch right: 2 to 3 inches, off the trunk

Mulch done right is one of the best things you can do for a tree. Done wrong, as a volcano against the trunk, it is one of the worst. The correct version is a wide, flat ring of coarse organic mulch, 2 to 3 inches deep, spread out toward the dripline and pulled back so none of it touches the trunk. Keep a clear gap around the base, with the root flare open to the air.

A proper ring earns its keep. It holds soil moisture, moderates soil temperature, suppresses the turf that competes with roots and invites string-trimmer damage, and as it breaks down it feeds organic matter back into the soil. Wide and thin is the shape that does all of that.

The mulch volcano does the opposite. A cone of mulch piled high against the trunk keeps the bark wet and dark, which invites rot and disease at exactly the spot the tree cannot afford it, and it draws roots up into the mulch where they circle the stem and become girdling roots. That girdling is often non-reversible. The fix on an existing volcano is to pull the mulch back off the trunk, expose the flare, and spread the pile out into a flat ring. More mulch is not better. Deeper is not better. Two to 3 inches, off the trunk, every time.

Deep and infrequent beats a daily sprinkle

Water is the input that decides whether a planting lives, and the rule is deep and infrequent, not shallow and often. A long soak that wets the whole root zone and then a dry-down before the next watering pulls roots down and out into the soil. A daily light sprinkle wets only the top inch, trains roots to stay shallow where they cook and dry out, and never reaches the rootball of a new plant.

Newly planted trees and shrubs are the priority, because for the first season or two they are living on a rootball the size of the container and cannot yet reach the water in the surrounding soil. They need regular deep watering through that establishment period or they die of drought even in a wet year. Established plants are tougher but still suffer in drought, scorching at the leaf margins and dropping interior leaves, and a deep soak during a dry spell is cheap insurance on a valuable tree.

The opposite failure is just as real and easier to miss. Overwatering, or a poorly drained soil that stays saturated, drowns roots by filling the pore space with water and forcing out the air, and the symptoms, wilting and yellowing and dieback, look almost exactly like drought. The check is to dig down and feel the soil. Dry means water. Wet and the plant is still wilting means the roots are drowning, and more water makes it worse. The right amount varies with soil, species, and weather, so read the soil rather than the calendar.

Fertilize to need, not by habit

Fertilizer is a tool for a measured deficiency, not a yearly ritual, and the most common mistake in this trade is feeding plants that did not need it. Established trees in soil with decent organic matter often need little or no added fertilizer, and a tree that is declining from compaction, deep planting, or drought will not be saved by a bag of nitrogen. Feeding a stressed plant before you fix the stress can push weak top growth the failing roots cannot support.

When a soil test shows a real shortage, feed to correct it. Slow-release formulations are the usual choice for trees and shrubs because they release nutrients over time and match how a woody plant takes them up, instead of a quick salt spike that runs off or burns. The ANSI A300 standard for soil management and fertilization, Part 2, frames the practice and points at the same principle: assess the soil first, then apply only what is needed.

Over-fertilizing has a cost beyond the wasted product. Excess nitrogen pushes lush, soft growth that aphids and other pests love and that disease moves into, loads the soil with salts that can injure roots, and on many sites runs off into water it should not reach. The rates, the timing, and the formulation depend on the soil test, the species, and the season, so set them with a certified arborist rather than the back of the bag.

Deep-root feeding and soil injection

Deep-root feeding, also called soil injection, is the arborist's method for getting fertilizer and soil amendments down where the feeder roots actually are. A probe injects a liquid solution under pressure into the root zone, commonly a few inches below the surface, on a grid spaced a couple of feet apart out under and beyond the canopy. The point is to place the nutrients in the root zone rather than on top of a lawn that intercepts them first.

The method does two things at once. It delivers what the soil test called for to the roots that will use it, and the act of injecting opens channels in the soil, which gives a modest aeration benefit on compacted ground. That is part of why it gets paired with compaction work on a struggling tree.

Two cautions keep it honest. Deep-root feeding is a delivery method, not a reason to fertilize, so it still answers to the soil test and the plant's actual need, and injecting fertilizer a plant does not need is just an expensive way to load the soil with salts. The depth, the rate, the spacing, and the blend are arborist calls tied to the test and the species, not a fixed recipe.

Monitor and scout to catch stress early

The whole proactive program runs on monitoring, because you cannot treat a problem early if you are not looking for it. Scout the property on a schedule, walk the plants, and read them for the early signs of stress before the client notices a dead branch. The point of the visit is to catch the trouble while it is still cheap to fix.

Know what you are reading. Early decline shows up as thinning in the canopy, smaller-than-normal leaves, early fall color or early leaf drop, dieback that starts at the branch tips, and scorch at the leaf margins. At the base, look for a missing or buried root flare, mulch piled on the trunk, mushrooms or conks that signal root or trunk decay, and bark that is cracking or sloughing. On the ground, probe for compaction and feel the soil moisture. None of that takes a lab. It takes someone who walks the site and knows what healthy looks like on these species.

Monitoring is also what feeds the pest and disease side. The same walk that catches a buried flare catches the early insect or fungal problem while it is small and treatable, and that observation is what drives the IPM decisions: identify it, decide whether it crosses the threshold to treat, and reach for the least-risk control. The full decision process is in the landscape IPM guide. The job here is to see it early and write it down.

Pruning for structure and health

Pruning belongs in a PHC program when it serves the plant's health and structure, not when it is just a haircut. The health cuts are the dead, the diseased, the broken, and the crossing or rubbing branches that wound each other and open the bark to decay. Removing a diseased limb takes the problem out of the canopy. Removing crossing wood stops the wound before it starts.

Structure matters most on young trees, where a few cuts early set a sound framework, one dominant leader, well-spaced scaffold branches, and no included bark in tight forks that will split in a storm later. That early structural pruning is some of the highest-value work in the program because it prevents the failure decades out for the cost of a few minutes now.

How you cut decides whether the wound closes or rots. Prune back to a branch collar or a lateral, never leaving a stub and never cutting flush into the trunk, so the tree can wall off the wound and grow over it. The ANSI A300 Part 1 standard for pruning sets the accepted practice, and a certified arborist sizes how much to remove, since taking too much canopy at once starves the plant and pushes weak watersprout growth. Topping a tree is not pruning. It is damage, and it creates the weak, hazardous regrowth a PHC program exists to prevent.

Biotic stress is usually secondary

Biotic stress is the living kind, insects and diseases, and on most declining landscape plants it is the second event, not the first. A borer goes for a tree already weakened by drought or compaction. A canker disease takes hold on bark stressed by a buried flare or sun scald. The pest is real and worth treating, but it is often a symptom of a plant that lost its defenses to an abiotic problem you can still fix.

That order changes how you respond. Spray the pest and ignore the compacted soil or the deep planting underneath, and the pest comes back, because the condition that let it in is still there. Correct the condition and the plant often recovers enough to hold off the next round on its own. This is the difference between PHC and a reactive spray program, and it is the reason the soil and root sections come first in this guide.

Some pests do attack healthy plants and need direct control on their own merits, and a few diseases move fast enough that you treat first and ask why later. Identifying which pest you have, whether it crosses the threshold to treat, and which least-risk control to use is the work of the landscape IPM guide. Within PHC, the discipline is to ask what stressed the plant first, then treat the pest as one part of the larger fix.

Right plant, right place prevents the problem

The cheapest plant health care happens before anything is planted, by matching the species to the site so it is not fighting the conditions for the rest of its life. A plant suited to the soil, the light, the moisture, the pH, and the space it has will grow with little intervention. A plant fighting the site stays stressed and stays a maintenance problem no amount of feeding fixes.

The classic failures are predictable. An acid-loving species in alkaline soil yellows with chlorosis it will never shake. A plant that wants good drainage rots in a low, wet spot. A large-maturing shade tree jammed under a power line or three feet from a foundation becomes a conflict and a hazard the day it reaches size. Salt-sensitive species along a road that gets plowed scorch every winter.

On an existing landscape you live with what is planted, but right-plant-right-place still guides the replacements. When a plant fails repeatedly in a spot, the answer is usually a different species, not another try with the same one. The site-and-species matching that drives a planting plan is design work, and it pays off as years of plants that do not need rescuing.

De-icing salt and winter injury

De-icing salt is a slow, chronic stressor on any plant near a salted road, walk, or lot, and like most abiotic damage it shows up well after the cause. Salt spray coats buds and twigs on the road side, and salt in the soil pulls water away from roots and pushes out the nutrients roots need. The symptoms are marginal leaf scorch, tip and branch dieback, and a thinning, one-sided look on the side facing the pavement.

The defenses are practical. Choose salt-tolerant species where salt exposure is unavoidable, screen vulnerable plants from spray, and most of all flush the soil with deep watering in spring to leach the accumulated salt down and away from the root zone before growth starts. Cutting back on the salt itself, or switching to a less-damaging de-icer in sensitive beds, addresses the source. Winter also brings sun scald on thin bark and desiccation on evergreens, both worth a note on the monitoring walk.

Protecting trees during construction

Construction kills more established trees than any pest, and it does it quietly, with symptoms that can take years to surface. The damage comes from three directions: compaction as equipment and traffic crush the root zone, root loss from trenching and grading, and grade change that either strips roots away or buries them under fill that suffocates them. A tree can look fine the day the job wraps and be dead three summers later, long after anyone connects it to the work.

The protection is decided before the first machine arrives, and it is mostly about keeping everything off the root zone. Fence the tree protection zone at the dripline or wider, the critical root zone reaches well past the branches, and treat the fence as a hard line: no equipment, no parking, no material storage, no traffic, no trenching inside it. Where access through the zone is unavoidable, a thick layer of wood chips or mats spreads the load and limits compaction.

Grade is the other killer. Raising the soil level over the roots even a few inches cuts off their oxygen, and cutting the grade severs them, so a grade change near a tree is a root problem that needs an arborist's input before the dirt moves. The slow death from compaction and grade change is the reason this belongs in the program: catch it at the planning stage, because once the roots are crushed or buried, there is no spray and no feeding that brings the tree back.

The recurring PHC program

Plant health care pays off as a recurring program, not a one-off visit, because the conditions it manages change through the year and the early problems it catches only show up if someone is looking on a schedule. A typical program is a set of timed visits across the season: a soil and root assessment, scouting walks, feeding to need when the soil test calls for it, and the targeted treatments that the monitoring turns up.

The contract is what makes it work for both sides. The client gets a property that holds its plants and fewer emergencies, spread across a predictable schedule and budget. The crew gets steady, plannable work instead of scrambling between dead-plant calls, and the recurring visits build the history that makes each next call faster and more accurate. A program also justifies the up-front conditions work, the compaction relief and the flare exposure, because the results show across seasons, not in a single afternoon.

Running it is a scheduling and records problem as much as a horticultural one. A field tool that holds the plant inventory, the visit schedule, the soil tests, and the treatment history per property is what lets the crew show up knowing what was found last time, what was applied, and what to check now. The difference between a real program and a glorified spray route is whether anyone can answer those questions on the next visit.

Diagnose, then prescribe per plant

PHC treats a diagnosis, not a property. The discipline is to figure out what is actually wrong with a given plant, then write a prescription for that plant, instead of running a blanket treatment across the whole site because it is on the schedule. A blanket spray hits plants that did not need it, wastes product, kills the beneficial insects holding other pests in check, and breeds resistance, all while leaving the real cause untouched.

A prescription names the problem and the fix together. Compacted soil under a declining maple gets compaction relief, not a fungicide. A chlorotic oak gets a pH correction the soil test sized, not a yearly feeding. A plant with a buried flare gets the flare exposed before anything else. Each is matched to what the diagnosis found, which is the opposite of a calendar applied to every plant the same way.

This is where a certified arborist earns the fee. Reading a stressed tree, separating abiotic from biotic, and choosing the correction that fits the plant and the site is judgment, not a recipe, and getting the diagnosis wrong means treating the wrong thing for years. Diagnose first. Prescribe to the plant. Treat to need.

Records: the inventory, the history, the tests

A PHC program lives or dies on its records, because the value is in the trend, and you cannot see a trend you did not write down. The plant inventory is the base layer: what is on the property, where, the species, and a condition rating you can compare against next visit. Without it, every visit starts from zero and slow decline goes unnoticed until it is a dead tree.

On top of the inventory sits the history. Log each monitoring walk and what it found, every soil test and its date and recommendation, every treatment with the product, rate, and target, and the result of the last treatment so the next decision builds on it instead of repeating a wrong call. That record is what lets you say a tree has thinned 20 percent over two seasons, or that the chlorosis is responding to the pH work, instead of guessing from memory.

Capture it in the field, not from memory back at the shop. A tool like FieldOS holds the inventory, the per-plant history, the soil tests, and photos against each property, so the record is built on the visit and ready for the next one. The crew that can pull up what was found, applied, and recommended last time is running a program. The crew that cannot is running a spray route with better marketing.

Field checklist

What to document

The record is what turns a visit into a program, so capture the condition, the action, and the reason for each plant while you are standing in front of it. The factors below are the ones that let the next visit pick up where this one left off, and the ones a client will ask about when they question the bill.

Common mistakes

• Blaming a bug or a fungus for what is really an abiotic problem in the soil or the roots.
• Ignoring a buried or missing root flare and treating the dying canopy instead.
• Building or leaving mulch volcanoes piled against the trunk.
• Fertilizing by habit on a calendar without a soil test, often on a plant that needed none.
• Overlooking soil compaction, the most common thing wrong under a declining urban tree.
• Watering shallow and daily instead of deep and infrequent, training roots to stay at the surface.
• Reacting to dead plants instead of monitoring and catching the stress while it is cheap to fix.
• Spraying the whole property on a schedule instead of diagnosing and prescribing per plant.
• Letting equipment, traffic, and grade changes hit the root zone during construction.

Standards and references

Plant health care comes out of arboriculture practice, and the framing belongs to the International Society of Arboriculture, which coined PHC to put integrated pest management techniques into a wider, plant-first program. For the technical practice, the accepted reference is the ANSI A300 family of standards for tree care operations: Part 1 for pruning, Part 2 for soil management and fertilization, and Part 8 for root management. They set the accepted methods that the rates and details hang from.

Two principles in those standards drive the whole proactive approach. Assess the soil before you fertilize and apply only what the assessment calls for, which is why the soil test comes before the bag. And manage the soil and roots as the foundation of plant health, which is why compaction relief and flare exposure come before chasing a pest. The soil test itself goes to a real lab, usually the state land-grant university soil lab or your cooperative extension, not a store probe.

Hedge the specifics to your conditions. The rates, the timing, the fertilizer blend, the watering volume, the species choices, the de-icing thresholds, and the compaction-relief methods all depend on the region, the soil test, and the species, and they are calls for a certified arborist, not a fixed recipe copied off a guide. What does not change site to site: most decline is abiotic, so start with the soil and the roots; get mulch and planting depth right; and monitor the plant and treat to need, not by habit.

Terms and definitions

Plant health care has its own vocabulary, and the same idea can read differently across an arborist's report, a soil lab result, and a maintenance contract. The terms below are the ones that carry the meaning of the program.

Plant health care (PHC)

A proactive program of scheduled inspection and care that keeps plants healthy by managing soil, roots, water, and nutrition, with pest control as one part

Abiotic stress

Damage from non-living causes such as compaction, deep planting, drought, excess water, salt, or mechanical injury, the source of most decline

Biotic stress

Damage from living causes, insects and diseases, usually secondary to an already stressed plant

Root flare

The point where the trunk widens into the first main roots, which must sit at the surface and stay exposed

Critical root zone

The soil volume a tree depends on for water and nutrients, reaching well past the dripline and shallow in the top 6 to 18 inches

Soil compaction

Soil packed dense enough to squeeze out the pore space roots need for air and water, the number one urban tree stressor

Deep-root fertilization

Injecting a nutrient solution under pressure into the root zone below the surface, a delivery method still governed by the soil test

Monitoring / scouting

Walking a property on a schedule to read plants for early stress and feed the pest and disease decisions

Girdling root

A root circling the trunk instead of growing outward, which thickens over years until it strangles the stem

Related tools

Calculators and readiness checks for this work

Compare your options

FAQ

People also ask

• What is integrated pest management?
• How deep do you plant a tree?
• What is site grading?
• What is right plant, right place?
• What is tree risk assessment?