Harmony Horticulture

Tree Protection During Construction

10.06.2017 by Kasey //

A few weeks ago, I had the privilege of speaking at the Arizona Community Tree Council’s annual conference in Prescott Arizona. This two-day event is a great way for Certified Arborist and tree care professionals to earn continuing education credits and also a get a chance to mingle with industry peers. This year, I taught part two of my class series, Tree Disorders of the Desert Southwest which focused on abiotic-caused disorders in trees. Last year’s class focused on biotic diseases, or biologically-caused plant problems. One of the topics covered this year was damage trees encounter during construction. Since we are seeing a surge in our construction industries (yeah economy!) it is a good opportunity to remind our construction managers, crews and property owners that existing trees need a little TLC and protection before, during and after improvement projects.

My eyes naturally gravitate towards trees as I drive the streets of the valley, and when i see a fenced in construction site with trees growing inside the protected zone, I am often disappointed to find the trees are a forgotten relic of the property. Vehicles parked under the canopy, tree trunks being used to as a backboard to hang signs, or a great shady spot for the concrete or painting crews to wash out their equipment. All of these can impact tree’s growing environment and therefore affect their health. Unfortunately, this type of abuse can cause extensive damage to established trees both above ground and below. Heavy equipment and repeated foot traffic over the root zone can compact soil, reducing the air and moisture space, which leads to root die back. Physical damage to roots from trenching and changes in soil grade can also impact not only the tree’s health but its structural integrity. Severing a root at least 4” in diameter within 10’ of the trunk can create a risky situation and a liability issue if it was a significant anchoring root. Construction chemicals deposited in the soil can also change the soil chemistry, which can be very challenging to remediate.

If you are planning on a construction project on your property and would like to salvage existing trees, here are a few steps to help to preserve and protect:

Hire a Certified Arborist to develop a tree protection plan.
Initiate a protection plan months in advance in order to help address irrigation changes which need to be made prior to the construction.
Barricade off area to protect the ‘critical root zone’ or the area where root damage can significantly impact the trees’ health. Do not allow access to this area by any construction crews.
Hang signs on the protected zone informing workers why this area is barricaded, and consider enforcing fines if restrictions are not followed.
Establish an alternative irrigation plan if water will be off to the property for a period of time. This is especially important during the summer months when even a few days of a water outage could negatively impact the tree.
Do not trim or remove foliage before or during the project. Think of every piece of green on that tree as a little food factory, making food to support the life of the tree. We want to keep all factories in full production during the project to support good health.
Fertilizer can be considered if the tree is not in good health going into the project. Ask your tree health care professional about organic acids or humic acids, which can help improve the below-ground growing conditions.
If trenching or digging is required within the critical root zone, hire a tree care company to ‘air trench’ instead of digging, then lay pipes over, under or around the existing root system. Remember severing roots can not only impact the tree’s health but can also cause structural instability.

Construction protection for this tree helping to prevent damage to both the roots, trunk and canopy.

If you have finished your project and now are seeing branch dieback, wilting or early fall leaf drop, you may want to have a tree care professional perform a root collar excavation or air spade the soil around the trees to investigate the damage that was done to the tree. Depending on tree species, some may bounce back a year or so after the project. Unfortunately, other species are not so forgiving once their roots are disturbed or damaged. The first step in recovery will be determining if the tree is at risk of failing due to major root damage. The second step will be to make the root system as happy as you can by addressing any compaction issues, fertility issues and also ensuring the tree is receiving adequate water for its age and size.

If you are planning a project and would like to protect existing trees on your property, please contact me and we can discuss how I can help develop a protection plan. Remember, some trees don’t show damage for many years after a project is completed, making it difficult to connect the dots between damage and current tree decline. Prevention is the best way to protect your trees, but sometimes giving your trees a little extra attention and care can help with heal back to a healthy state.

Top Tree Problems Encountered

05.23.2016 by Kasey //

This month’s ACLP class series is Tree and Shrub Pruning and it reminded me of all the reasons why we should hire a professional to prune our trees. Trees are often the forgotten element in our yards. Sure they provide us shade and refuge from the scorching summer sun, but who calls their tree care professional for an annual health assessment? Generally most of my calls are for ailing trees, not the healthy ones. We typically don’t notice the healthy growing trees until they fall in a windstorm, show symptoms of a disease or pest or begin changing in appearance.

Older olive tree showing years of inconsistent watering and care.

Here are the top reasons why I get called to properties:

1. Change in growth: yellowing foliage, wilting or defoliation

Nutritional disorders, usually due to poor tree choice for the site= queen palms… when will everyone learn: They. Just. Do. Not. Grow. Well. Here. Okay, I’m off my soapbox.
Too much or too little water: too much water leaches nutrients, reduces necessary oxygen to roots, slows growth and can make conditions conducive for root diseases. Too little water can also reduce growth, cause wilting, leaf tip burn due to the high concentration of salt in the soil.
Disease or pests: while we we don’t have many plant diseases in our arid region, there are a dozen or so pathogens in our soil that can impact plant health or kill a plant. We also have a number of nasty pests that can wreak havoc on select plants. The top disease I diagnose is Texas Root Rot and the pests I most frequently encounter are the Agave Weevil or the Palo Verde Borer.

Pine trees declining due to insufficient irrigation after turf to granite conversion.

2. Death of tree limbs/ tip dieback

Many times there has been a change on the property, construction damage or root disruption being the biggest culprit
Plant diseases can also cause tip dieback
Incorrect soil grade, either from the tree being placed too deeply in the hole at planting or from soil being added to the existing soil, making the grade higher. These are very common mistakes made in the landscape and unfortunately trees may not show any signs of stress for many years, making it difficult to make an initial diagnosis. That’s why I most often keep digging, until I find the right answer.

Palo verde has been planted too deeply, which can easily be corrected soon after planting.

3. Broken limbs- can the tree be saved?

Depends on the situation. Fast growing species generally have a better chance of recovering than slow growers.
Can be subjective- do you want to look at an an ugly tree for 3 years until the tree fills in? No one is judging, it’s your property and if you want a new tree, plant a new tree. Please make sure you hire a certified arborist to help train the young tree for the best branching structure to help prevent limb failure in the future.

4. Overall decline in health and vigor of the tree

This can be caused by a number of issues, but the first thing I would look for is irrigation efficiency. Generally when trees are planted, two drip emitters are installed within 12” of the trunk and then they are forgotten. As trees grow, they require a greater volume of water to thrive, especially non-desert trees. Moving and even adding drip emitters to the dripline of trees will help the delivery uniformity of water to each tree. Also, irrigation schedules should be adjusted monthly to meet the water requirements of each tree, which depends on time of year, temperatures and humidity levels and of course the size of the tree.

Sisso showing dwarfed yellow foliage is growing in saturated soils due to irrigation leak. — Sissoo showing dwarfed yellow foliage is growing in saturated soils due to irrigation leak.

As we approach our summer season, I recommend inviting an ISA Certified Arborist to your property to inspect your trees. The arborist should not only look at the structure of your tree but also its overall health and make recommendations for how to improve the growing conditions of the tree. If you do need pruning, please, please please make sure the company your hire is properly insured to perform tree work, which is not the same coverage a landscaping company typically holds.

If you do have tree health care concerns, please feel free to invite me to your property for diagnosis. I am also happy to provide your referrals for reputable companies who will be able to perform the work.

What’s in a name?

04.11.2016 by Kasey //

I love getting corrected. Really I do! I think it it hard for some to admit being wrong, or maybe misinformed but it’s really hard to thank the person for helping enlighten you to facts.

For years I have used ‘Agave Snout Weevil’ to name the little beast that takes out gorgeous Agave. It was recently brought to my attention that essentially you are calling it an Agave Weevil Weevil, since by definition, all true weevils have elongated snouts. So from this point forward, we will be calling Scyphophorus acupunctatus by Agave Weevil.

Which brings me to another point: the common name. We know each and every known organism on this planet is classified and named with binomial nomenclature, or the genus and species. The Genus is capitalized followed by the lowercase species. They are italicized but can also be underlined, which is appropriate especially when written.

So back to the common name. Many plants have multiple common names, especially if grown in different regions. Let’s look at the the sissoo tree, Dalbergia sissoo, which is also called Indian rosewood in our area. Since this tree grows in many places around the world, there are multiple common names: Indian rosewood, East Indian rosewood, dalbergia, Himalaya raintree, Indian dalbergia, penny leaf tree, penny-leaf tree, shisham, sisso, sissoo. This makes it extremely difficult when shopping for plants by their common name. You may think you’re ordering one plant, but you receive something completely different since different species can also share a common name.

To add even more confusion, we add cultivars and varieties to plant names, which are listed after the species. You’d like to plant a Texas sage, but which one? There may be a number of Leucophyllum frutescens, including. L. f. var. white cloud, L. f. var. heavenly cloud, and L. f. ‘Compacta’ grown at your local nursery, which, to most look nearly identical.. As you can see, requesting a Texas sage can be a big mystery of what it will look like (size, growth habit and flower color) if you are not specific with what variety you’d like.

Common names are written all in lowercase, unless there is a proper name included in the name: Perry’s penstemon, California fan palm, or Canary Island date palm. Some plant breeders will also name special varieties of plants, trademarking them such as The Swan Hill Olive tree. Generally trademarked plants are somewhat special. Either they are bred for disease resistance, special features like a magnificent flower color, or even superior growth like the Prosopis glandulosa ‘AZT’, which has been bred to be thornless.

Once you’ve learned the scientific name, the name changes. Seriously, they change scientific names all the time and believe me, it is hard to keep up! A great place to check if a scientific name is current is at The Plant List. If you think you know the name of a plant, but someone corrects you, take note and do a little digging to see if your friend or neighbor is accurate. Maybe the you got it right this time, but if not, be grateful and thank them for helping build your floral or fauna knowledge.