Many times, as a climber, I would find myself looking at weird holes in the bark that I found way off the ground in the canopy of large tree. At the time I had no idea what I was looking at but I always wondered what they were. Years and years later, I did some research and found that they were borer holes which meant the tree was infested with a pest that was ruining the nutrient transport system. Thinking back now, I was doing some Plant Health Care (PHC) without even knowing it by finding a pest problem and at least letting the client know. So this got me to thinking about how many other ways are we doing PHC without doing what everyone always thinks of when it comes to PHC.
For years I always thought of a PHC technician as a person in a full body suit with goggles and respirator spraying super harmful chemicals all over the landscape trying to kill EVERY bug in site. Unfortunately this is the same idea that a lot of tree climbers have about PHC techs because we have watched the big lawn care treatment companies come out and do just that. Today, PHC has become much more of a natural approach to taking care of trees by focusing on the urban soil and feeding the microorganisms instead of blasting it full of fertilizer for a quick fix. Also by finding ways to de-compact hardened soils that don’t let air or water reach the roots of a declining tree. All of this can be done without the respirator, goggles or nasty chemicals!
One of the first ways that we are doing PHC as climbers is with our tree risk assessment before entering the tree. We should be walking around every tree before we enter it to make sure there are no large defects, co-dominant stems, dead sections, heaving root plate, large cracks in the ground, cavities with critters inside or that the tree isn’t in a major decline. We are doing all of these things to make sure that the tree is safe for us to climb or rig out of. We are also identifying defects in the tree that could possibly be causing issues with the overall health of the tree. If we are identifying issues that could affect the overall health of the tree, are we also identifying things that could be treated through a PHC program that includes cabling or bracing, soil de-compaction, or adding compost to help boost soil nutrients which in hand helps the overall health of the tree? Yes we are!
Many times walking into a client’s yard, a keen eye can easily point out multiple defects of issues with a tree or the landscapes overall health. Here is a photo of a client’s tree that we had to work on. As soon as I walked onto the property I knew that the grade had been changed and that the tree needed a cable installed to mitigate the risk of the large section falling onto their house in the midst of a wind storm or an ice storm. I knew that the grade had been changed because trees should never look like telephone poles. Trees have buttress roots that should taper out and away from the main line of the trunk. This tree stuck straight out like a utility pole. In turn, we came out with an Airspade and excavated all the dirt away from the trunk to help bring water and air to the roots that had been covered the previous year when the grade had been changed. Also, knowing that other trees had been removed from around this tree, we decided that a cable was even more needed because the wind break that the other trees created were now gone so the wind load would be higher on the co-dominant stem that we identified when we walked on the property. All of this is PHC even if we aren’t applying chemicals up in the air or in the soil!
Speaking of using an Airspade, many times when dealing with Norway Maples (Acer platanoides), you can almost guarantee you will find a girdling root just above or just below the soil’s surface. Girdling roots are roots that grow around the trunk of the tree in a circular pattern instead of out and away like other roots. These roots can grow so tightly around the trunk of the tree that they restrict the flow of nutrients and water from the roots to the leaves. This can cause an obvious decline in the trees health and in severe cases cause the tree to die. Many times a girdling root can be identified by an indentation in the trunk of the tree in on area or by a lack of diameter change where the tree enters the soil. By excavating the soil by hand, the climber can easily see the roots wrapping around the base of the tree. The next step is to either excavate the rest of the soil by hand or with an air powered excavation tool such as an Airspade or a homemade version. This tool blows air out of an industrial air compressor at the roots and soil which in turn blows off without damaging the roots. This is more expensive than excavating by hand but far more efficient and far less invasive for the delicate roots. Once the girdling root has been identified, it can be cut with a handsaw or hammer and chisel.
When talking to a client about their trees, it’ s always good to check how hard the soil is around the base of the tree and throughout the drip line. Most trees in new neighborhoods in our area have been back filled with horrendous clay soils that turn to rock in the summertime. In other areas like Los Angeles, it seems the soil is always compacted and hard making the growing conditions for most trees very difficult. By using the air excavation tool, you can de-compact the soil and then blend in manure and compost to help boost the soils microbial content. Adding a layer of mulch will also help the soil retain more water, help with compaction and help with feeding the microbes in the soil as well.
Adding cables to help with supplemental support for weak limbs is another way to do PHC without even knowing it. If a tree were to lose a large section of it’s canopy, it could be very detrimental to the client’s health or property but it is also quite detrimental to that tree’s health as well! By mitigating the risk of the tree losing a large limb or lead, you are mitigating the potential risk to the tree’s health. Cables are installed, in general terms, about 2/3rds of the way between the defect in the tree and the tips of the tree. Cables are made of various materials such as rope and steel which are installed to help add supplemental support to the tree in the event of a wind, ice or even heavy rain storm. Again, this is something that you as a climber are already doing to help with Plant Health Care.
Hopefully some of these ideas can give you a different perspective of what Plant Health Care is and how you can get involved with it without needing to get additional certifications or applying chemicals into your client’s yards. Many of these things you are probably already doing without even knowing you were taking part in a PHC program. Now start implementing it into every yard and making each yard a healthier place for the tree to live!