Good tree care involves being proactive with potential issues rather than reactive
Problems with trees are inevitable. For a variety of problems – insects, diseases, abiotic causes – they’re going to happen. The only question is, how are you going to deal with them? Are you going to prevent them from occurring, or fix them after they develop? The other option is to simply ignore them…but that borders on being negligent, as property owners of all types are responsible for proper care of their dwellings and plantings; as such, ignorance is bliss only for a short time.
As with most other things in life, tree problem prevention is better than the alternative of fixing it later. All in all, prevention is simpler, less expensive and requires less time than curative procedures such as pruning, cabling, bracing, pesticide applications and removal. There are many steps to be taken for prevention.
When proper planting procedures are followed, young trees develop similarly to that which occurs naturally: When a mature tree drops a seed to the soil underneath and Mother Nature provides the essential elements – sunlight, nutrients, moisture, supportive soils, etc. – that nurture its growth and development.
So, what does a healthy, Mother Nature-fostered (sometimes referred to as “volunteer”) tree look like? Its roots are horizontal, radiating from the trunk in all directions, not circular, wrapping around the root flare. The roots are within an inch or two of the soil surface, growing in the native soil she provided without amendments. Its trunk is straight and strong without wounds, marks or compressions incited by staking efforts.
In order to best simulate natural planting, efforts should be taken to place the root ball at the ground level, to remove bags, wires and fabric, to unwrap any roots that have begun to circle in the root mass and to avoid amending with compost or potting soils to keep the soil moist – not soggy or dry. In the absence of natural rainfall, avoid fertilization unless soil test results indicate a need and remove any staking wires after a season of growth. When this regime is followed, maladies such as stem girdling roots, trunk damage and basal root injury usually can be prevented.
Keep mowers away
Injuries to the trunk are a limiting factor in the health and well-being of a tree, as the just-under-the-bark cambium layer is crucial in the successful transport of water and nutrients throughout the tree. A classic injury to a bole is repetitive damage from turfgrass maintenance equipment, sometimes referred to as “mower blight.” In most cases, the damage of that one particular contact with the basal plate is not ultra-serious; however, due to the number of times that a small tree is commonly struck during a given growing season, chronic, sometimes irreversible, damage occurs.
Keeping mowing equipment away from the trunk is a key prevention step for this tree problem. Perhaps the simplest and most effective method is the application of a thin wood chip mulch layer, beginning about 6 inches from the trunk and extending as far out into the landscape as the client will allow. Not only is this a replication of Mother Nature’s provision, a thin (1- to 2-inch) mulch layer will retain and hold moisture and suppress competing weeds and grasses. In short, it keeps moisture in, weeds out and mowers away.
Correct early defects
Defects that develop early in a tree’s life are best corrected sooner than later. Co-dominant leaders, leaning trunks and sunscald are three of the most common early defects. In the first year of growth, the size of the stem tissue of the double or triple leader is likely to be an inch or so in diameter. The solution in most cases is to remove the weaker of the two or three. If this is done in the first growing season, wound closure is much more likely than if the pruning is done after two, three or four years of growth. The prevention step in this case is two-fold: prevention of decay due to slow wound closure and prevention of splitting of the co-dominant leaders due to the poor branch angle arrangement of the tree.
Attempts to correct leaning trunks and sunscald injury that are made in year one also are much more likely to be successful than corrective actions taken later in the tree’s life. Sure, bringing the angle of lean back to 90 degrees is stressful at any time; but, many fewer roots are disturbed earlier than later. Similarly, white boards or sheeting that reflects winter sun on the south and west side of the tree should be done during the first, not second, third or later winters for the greatest efficacy.
Choosing well matters
Plant something good. Simple, but true.
In general, it’s best to avoid species that are borderline for the area. For example, planting aspens, Bradford pears, poplar, corkscrew willows, sugar and Norway maple usually results in disappointment in the Great Plains. In many cases, these species perform just fine in three out of five seasons/winters, but it’s those other two where trouble arises. Lack of winter hardiness, sunscald, disease pressure and splitting/cracking are typical issues with poorly adapted species. Instead, local botanic gardens and arboretums are the best sources of recommendations for well-adapted species.
Another aspect of tree species choice is to insist on diversity, with a basic guideline for planting no more than 10 percent of any one genus on a property. An illustration of this tenet lies with elm and ash. All species of Fraxinus are susceptible to damage by the emerald ash borer. We’ve all seen way too many properties with a couple of green ash, a white ash and even a blue ash as the main stalwarts of the landscape, only to see the devastating effects after infestation.
Location in the landscape
Overly close planting is a perpetual problem in the landscape. Usually caused by impatient property owners or opportunistic landscape designers, trees that are installed too closely begin competing for light, water and nutrients at an early age, compromising the overall health of each. To allow adequate room for growth, plant trees no closer than half of their expected mature spread apart, (plus or minus) for the life expectancy for the plantings. But this tenet only works well if the original property owner remains throughout the life of the trees. Since the average resident moves every seven years or so, it’s best to err on the plus side.
Droppage of leaf and other debris from trees also is a consideration in terms of location. Driveways, pools and decks are targets of unwanted tree litter; these hardscape elements should be taken into account when the location of a new tree is sited. As well, the separation of turf and ornamentals is a helpful guiding landscape design principle to prevent location problems in the landscape. As each require differing amounts/types of fertilizer, water and pest control applications, it’s best to keep them separated.
In terms of problem prevention, the most important year in a tree’s life is the first one. Some simple but effective guidelines are:
- Moist soil, not soggy or dry: Check frequently for proper moisture level and add or delay irrigation as necessary.
- Thin mulch layer: Place a 1- to 2-inch layer of organic mulch – such as wood chips, pine needles or bark chunks – around the tree. Avoid rock, stones and rubber if possible, and don’t pile it on the trunk.
- No fertilizer: It’s most important to establish roots the first year; fertilizer applications often stimulate shoot growth at the expense of root production.
Frequent inspection for leaning, moisture level, insects and diseases: Consider offering customers a monitoring package as an added value piece.
Consider protection of the southwest side of the trunk: Especially for thin-barked deciduous species; bark damage in the first year often produces a defect from which trees never recover.
It doesn’t always work
Prevention is certainly more effective and less costly than ignoring problems and just letting them occur and cause further damage. Yet, sometimes, it just happens in spite of an arborist’s best efforts. For example, stem-girdling roots can be created as a result of root expansion into a hardpan, which doesn’t allow for penetration. Usually in this case, the root will either die or turn sideways and continue growth in another direction, sometimes in close proximity to the tree trunk, resulting in a stem-girdling root.
Even so, prevention is good tree care and worthy of your attention to detail.
COVER AND ALL PHOTOS: JOHN C. FECH