As summer transitions to fall, a client’s attention often turns to trees in the landscape. Why? In the North, Kentucky bluegrass and tall fescue lawns are recovering from a beastly summer; in the South, Bermudagrass, centipedegrass, zoysiagrass and bahiagrass are easing into dormancy or at least semi-dormancy. These conditions can work to your advantage as a teachable moment and business opportunity.
What now? What later?
In a whole year of tree care, there are good and bad times to perform certain practices, as well as “it-doesn’t-matter” times for others. The big question on everyone’s mind is pruning, which is a yes-and-no practice in the fall. When it comes to cutting live limbs to regain structure, the answer is “no” for at least two reasons.
First, fall limb removal leaves open cuts exposed to cold winter winds, leading to excessive desiccation. Secondly, the pruning wounds are slow to close as the callus roll and woundwood production is much more vigorous in spring, delaying closure for several months. As well, depending on which part of fall the cuts are made, the action may encourage excessive sprouting and sucker growth, which may not have time to harden before the onset of winter.
While spring is best for removing live branches, fall is a great time to remove dead wood to limit limbs falling on targets such as patios, houses, cars — anyone or anything of value. Removing dead wood limits the client’s exposure to damages from liability claims from passersby or neighbors, especially if the landscape manager or arborist has informed them previously of the tree’s flaws. Because the optimal approach is to avoid removing live wood, it’s best to limit cutting into living tissue when removing dead limbs, at least to the extent possible, and to schedule removal of the remaining stubs in spring.
Tree hazard awareness
Once the dead wood is out, fall is a great time to perform a simple tree hazard awareness test, especially with an assist from a certified arborist from the International Society of Arboriculture. In fall and winter, flaws such as crossing limbs, lion’s tails, suckers, hangers, etc., are so much easier to see when leaves and dead wood aren’t in the way.
Hazard awareness is a methodical documentation of tree flaws and their relative risks to the client and their property. Defects such as stem girdling roots, buttress decay, co-dominant leaders, hangers, crossing limbs, trunk decay, previous flush cuts, topping, poor live crown ratio, inadequate potential rooting space and others are noted and communicated to the client. Naturally, this is of immediate benefit to them, but also to the contractor as it provides for a steady flow of necessary work in the months to come.
Anytime care practices
Speaking of additional beneficial practices, there are many that can be performed at just about any time in the year.
First is a review of the status of the mulch placement and depth. The key premise to keep in mind related to mulching is a quote from Bruce Fraedrich with Bartlett Tree Experts: “Mulch is a tree root treatment, not a trunk treatment.”
As such, good mulch placement should be 6 inches away from the trunk, be 2 to 3 inches deep and extend as far into the landscape as is practical. It should not be piled against the trunk into the shape of a “mulch volcano” where rodents can be protected and provided with food and a micro-climate created for basal decay organisms to gain a foothold.
The second consideration with mulch is what it looks and feels like. Arborists and horticulturists alike strongly prefer organic material, such as wood chips, pine needles and bark chunks. There are at least six reasons to favor organic mulch:
⦁ It mimics forest conditions, which is favorable to trees in the created landscape.
⦁ It lessens temperature fluctuations.
⦁ It lowers weed competition.
⦁ It eventually degrades and introduces organic matter.
⦁ It slows runoff.
⦁ It keeps mowers away.
Sure, rock and stone have their place, such as in hot sunny spaces where nothing else will grow, in swales, dry riverbeds and around grain bins. Those materials are just not appropriate around trees.
Moisture matters
Fall is a great time to check for moisture levels and teach clients how to monitor it on a weekly basis. The tools for checking are simple and easy to come by. A simple probe, such as a piece of rebar, a long screwdriver or a short surveyor’s grading stick, is great.
For the vast majority of trees, we want the soil to be moist, not soggy or dry. These tools are helpful in two ways. First, the physical force required to push the probe into the soil is a good indicator of soil moisture; if it slides in easily, the soil is likely very moist. Perhaps the best indicator is the look and feel of the blade after it is pulled out; if it is dry and powdery, the soil needs a thorough soaking.
With soil moisture in mind, fall is also a good season to do a quick irrigation system check, especially if the tree is in the middle of turf. Lawn irrigation systems can overwater or underwater trees quite easily. Simply place some collection devices at various locations under and away from the canopy or drip line of the tree, then run the irrigation system zones that are within 50-60 feet of the tree trunk.
Showing the different amounts collected to the client/homeowner will be informative for the sake of the lawn, but perhaps even more enlightening for the tree’s root system since they are growing in the same space. During the show and tell, communicate with the client/homeowner about expectations and what tree symptoms they might have seen in the spring and summer.
Fall tree care no-no’s
There are at least two no-no actions to take regardless of the time of year. As most readers know, topping or the cutting of limbs back at a uniform location to lower the tree’s height is a very poor practice. This procedure usually results in lots of aberrant regrowth from embedded buds on the lower branches that are weakly attached to the limb. New growth from these formerly suppressed buds is only attached to the outer ring of sapwood as opposed to original stems tied deeply into the heartwood.
The other action to stay away from is to elevate the tree’s height by removing lots of the lowest branches. It’s usually done to allow greater sunlight penetration with hopes of encouraging denser turfgrass growth under the canopy.
While the turf growth usually improves to some degree, the canopy’s live crown ratio is greatly reduced, commonly from three-fourths branches with leaves to trunk to half-trunk and half-live crown. This drastic step results in lowered photosynthesis and greater susceptibility to damage from windstorms.
