Spring: A Great Time to Fertilize

By Chris Gill
March 7, 2024

Dear Reader,

Spring is a great time to fertilize trees. As the soil begins to warm up, feeder roots become active and begin to look for nutrients in the soil. A general Spring fertilization provides trees with a boost of macronutrients (typically nitrogen, phosphorus, and potassium) which are essential to trees as they enter the challenges of a new growing season and require energy to develop new leaves, branches, and roots. Spring fertilization can also benefit trees recovering from the winter stresses of cold temperatures, desiccating winds, and potential exposure to de-icing products around tree roots. 

At Russell Tree Experts, we fertilize trees through a technique called deep-root fertilization. We perform deep-root fertilization by using a lance to inject liquid fertilizer under pressure deep into the feeder root system in a soluble form that is easy for the tree to take up. This is superior to a traditional surface application where a granular fertilizer is spread over the root system of a tree but still requires time for the product to break down and work itself into the soil. Deep-root fertilization allows nutrients to pass by the competitive roots of turf, weeds, and other ground covers to maximize uptake for the tree. The process of deep root fertilization also helps to loosen up compacted soil around the tree to promote better root growth while also allowing water and oxygen to more easily reach the roots. Compacted soil is a common problem in urban landscapes and can reduce a tree’s ability to access nutrients.

STEP 1: Fertilization

In the spring or fall the soil around the tree will be fertilized with a custom selection of the following: Nitrogen (N), Phosphorus (P), Potassium (K), Iron (Fe), Manganese (Mn), and liquid compost - all essential nutrients for healthy soil and root systems. The goal is to provide the tree with the best soil chemistry possible.

STEP 2: Metabolic Processes

The tree acquires carbon, hydrogen, and oxygen from the atmosphere and from water. Using light energy from the sun (photosynthesis), these are combined to produce glucose. Other essential nutrients are gathered from the soil. The tree uses glucose and essential nutrients for growth, reproduction, and pest/disease resistance.

STEP 3: Evapotranspiration

Through this process the tree is able to move nutrients from the soil, up the trunk, and into the outer canopy, carrying them dissolved in water to be used as needed. This process continues throughout the growing season.

STEP 4: Reduced Nutrient Levels

In urban soils macro and micronutrients can be depleted for several reasons, limiting metabolic processes. Fertilization helps maintain nutrient availability to trees by supplying needed elements that have been used by the tree or leached out of the soil. [BACK TO STEP 1]

Trees that are showing dieback in the canopy, poor leaf color, stunted growth, or low vigor are all great candidates for fertilization. When putting together a fertilization plan, it is important to also consider tree type and location. Most trees benefit from a general fertilization, but many tree species may require more specific nutrients. Some of these nutrients can be lacking in urban and highly developed environments. For example, many woodland species that grow naturally in low-lying areas (ex: river birch, pin oak, and red maple) often require the addition of manganese to a fertilization program for long-term health and vigor when planted in a residential neighborhood. The specific nutrient for which a tree is deficient may not always be obvious, especially in a young or newly planted tree, but can be determined easily through soil and tissue testing. Russell Tree Experts can provide these testing services as needed.

Trees in native areas are less likely to require fertilization. This is due to the less disturbed nature of the soil and to the natural breakdown of leaves, sticks, and other organic matter continually providing nutrients to the soil or a “natural fertilization.” Trees in urban or highly developed areas are less likely to experience “natural fertilization” due to interference from hardscapes and through regular landscape maintenance practices including raking out yards and landscape beds. 

Soil quality is the key to good tree health and longevity and Spring fertilization is a great way to start the soil improvement process. There are various considerations that are made when selecting a fertilizer for your trees including the type of tree and the location of the tree in your landscape. Consulting with one of our certified arborists can help determine the specific nutritional needs of your trees and get the process started!

Sincerely,

Chris Gill I Regional Manager, Russell Tree Experts

Chris joined Russell Tree Experts in 2015 and has been in the green industry for over 15 years. When not at RTE, he enjoys spending time with wife & son, wakeboarding, and hunting. His favorite trees are the white oak & sugar maple for their beauty and uses beyond the landscape. Chris is an ISA certified arborist, EHAT certified, CPR and first aid certified, holds an ODA commercial pesticide license, and holds a tree risk assessment qualification (TRAQ).

More Tree Preservation Articles!

Tree Bracing 101

Dear Reader,

Trees adorn our landscapes, offering shade, beauty, and a connection to nature. However, ensuring their structural integrity and stability is vital for their longevity. Common tree preservation services that you may be familiar with are tree pruning and mulching. Other uncommon services could be cabling or trunk injections depending on the specific tree. However, throughout my 4+ years of working at Russell Tree Experts, one service that I have not heard of up until this year is tree bracing! Let's delve into the world of tree bracing to understand the process and benefits!

What is Tree Bracing?

Tree bracing? I couldn’t initially picture what this meant when first hearing it. Let’s first break down tree bracing into two words. Tree. Bracing. Tree: A woody, perennial plant typically having a single stem. I know what that is. Brace: To make (something) stronger or firmer, or to prepare for something difficult or unpleasant. So would it be a solid guess that tree bracing is the process of making a tree stronger? Yes! That’s exactly what it is!

Tree bracing is a tree preservation service to reduce the risk of two or more stems from splitting apart or to fasten a split or cracked union together, thus improving the overall structure of your tree. This is achieved through the installation of brace rods to prevent select tree unions from spreading or twisting apart or to prevent a split or cracked union from worsening.

This sounds great! Let’s start bracing every single tree to improve their overall structure! Well, not so fast. Only certain trees will stand to benefit from tree bracing. Just like fertilizing trees with manganese or iron to treat a manganese or iron deficiency, this service is only recommended for trees that need it, otherwise there would be either no noticeable effect or even a decrease in structural rigidity. Just like with pruning, which involves removing (or “wounding”) the tree’s crown of undesired parts, bracing is a semi-invasive procedure that involves installing large threaded steel rods into the trunk of the tree, so we only want to install brace rods when the net result is positive and beneficial. 

What Trees Should Be Braced?

So what trees should receive tree bracing? Well, as mentioned earlier, trees with a split or cracked union could benefit from brace rod installation. A split or cracked union should be easy to spot, especially in the winter in the case for deciduous trees as there is little to no foliage. A limb can split or crack due to various reasons like included bark (bark that is partially or fully embedded into the tree’s wood), improper pruning, disease, and storm damage from adverse weather like lightning, heavy winds, rainstorms, and thick layers of ice just to name a few. A split or cracked union can also occur from structural defects like large, long, horizontally growing limbs and codominant stems. If the limb is large and long and growing more horizontal rather than vertical, there could be a lot of weight-related stress near the union that could cause it to split if the limb is not supported properly or if end-weight reduction pruning does not occur. Codominant stems are two similarly sized stems originating from the same point of the tree and growing in the same, general direction. They can be characterized as having a tight “V” shape near the union or by both of the limbs competing to be the central leader of the whole structure. This is not ideal for a tree’s structure as they are prone to splitting during adverse weather conditions. In scenarios where removal of the branch or tree is not viable or preferred, tree bracing serves as a beneficial solution or alternative.

What Are the Benefits to Tree Bracing?

Tree bracing can be beneficial for a tree as they can minimize movement, ensuring the splits or cracks do not occur or worsen, especially during strong weather. A tree with poor structure or a split or cracked union may not want to be removed by the owner as it is a specimen tree (a tree chosen as a point of focus in a landscape) that provides aesthetics, shade, real estate value, or more. For some trees, it may also be unnecessary to remove them simply because of one or two weak, treatable unions that could even be healed over time. Tree bracing aims to improve the tree’s structure at a choice union and to give its owner more peace of mind that a union or limb has a decreased chance of failing, which would potentially end the tree’s life, or to keep it from falling onto something like a house, car, driveway, or anything else near the tree.

The Tree Bracing Process

Here at Russell Tree Experts, we use the ANSI A300 Tree Support System Best Management Practices to help guide us! With that said, before tree bracing begins, we typically prune the tree's crown to reduce weight and then install one or more cables in the crown to support the suspect union(s) from above. Once these initial steps are complete, we install a specified size and quantity of brace rods in your tree in accordance with the ANSI A300 Tree Support System Best Management Practices. The size and quantity is determined by factors such as the tree’s diameter below the union, number of limbs or unions being cared for, and whether or not there is or is not a split or crack present. To install the brace rods, holes are drilled straight through the tree near the union. The threaded brace rods are then fully inserted and will have excess rod on both ends. The brace rods are then secured with one or more washers, a lock washer, and a nut on both ends. The connections are then tightened as firmly as possible. Afterwards, the excess length of threaded rod is cut off close to the nuts and subsequently peened off to prevent any movement of the nuts. And voila! The end result is a tree with increased structural integrity and a reduced chance of failing! 

I talked with my coworker Jacob, our Training & Development Manager and an ISA certified arborist, read through the ANSI A300 Tree Support System Best Management Practices, and looked at other resources online to see if it was an acceptable practice to drill holes through a tree to install brace rods. After considering a variety of sources, the general consensus is that the overall impact is minor because almost all of the drilled wounds are filled with threaded steel rod (except a 1/32'' gap), allowing the tree to compartmentalize the wounds rapidly, and that tree bracing should be done on trees that have a bigger concern to worry about, such as two codominant stems or a split union.

Professional assessment is imperative to determine the necessity of bracing for a tree. Signs such as co-dominant stems or split or cracked unions should prompt owners to get an opinion from an ISA certified arborist. After researching, observing, recording, and photographing various trees being braced, I felt empowered and motivated to share my newfound knowledge on this not-so-commonly heard of tree preservation service! The main purpose of this Arbor Ed article is to educate and share my findings, but Russell Tree Experts does provide tree bracing services should you want or need it! Our regional managers are all ISA certified arborists and can provide a free inspection and quote! Below are some videos about tree bracing! 

Sincerely,

Enrique Arayata I Media Production Coordinator, Russell Tree Experts

In his free time, Enrique enjoys working out, hanging out with his girlfriend, video production and photography, cars, technology, cooking, and watching new movies and YouTube videos. He has a BA in moving image production with a double minor in film studies and studio art specializing in photography from The Ohio State University, an AA in web graphic design from DeVry University, and is an FAA Certified Remote Pilot.

Learn More About Tree Bracing!

Root for your Roots!

A tree is only as healthy as its roots. Luckily, Russell Tree Experts offers a variety of root-health services! The powerhouse of our root-health services is the air spade. This tool, when attached to a powerful air compressor, is capable of removing soil without damaging tree roots. (Full disclosure and fun fact: air spading is my very favorite type of tree care to perform!)

Root Collar Excavation

“Say NO to Girdling Roots!”

The most common root-health service is root collar excavation. In this procedure, our technician begins at the tree's trunk and removes soil approximately a foot outwards to reveal the root system closest to the tree. From here, roots that are squeezing the trunk or each other can be selectively removed, thus improving the passage of water and nutrients from the roots to the leaves. Once the soil near the trunk is removed, additional improvements can be made such as removing twine, burlap, or other nursery products left during planting, or correcting the soil depth of trees planted too deep. In my experience, this is the single most beneficial process to long-term tree health. Maples and sweetgums are especially prone to girdling roots. Signs of trunk girdling in other trees include lack of flare at the base (which indicates the tree is planted too deep), flat spots in the otherwise round trunk, early fall color and leaf drop, and excessive stress during summer drought. Root collar excavations should be performed in winter when trees are dormant, but when the ground is not frozen. 

In limited quantities, roots can also be exposed and pruned to prevent damage to patios, driveways, or underground utilities. This method of root removal is far less damaging to tree health than traditional shovel/backhoe techniques. An ISA Certified Arborist® should always be consulted before this type of work is performed because excessive root removal can cause instability and rapid tree death. Air spade trenching and root removal can be performed year-round except in the case of some trees that may be highly stressed or experiencing severe drought conditions.

Even when a tree is planted at the proper depth, has plenty of soil space, and with no girdling, the trunk can still benefit from root-health services. We offer three related, but progressively more intensive options to treat the entire root zone and not just the area around the trunk.

Vertical Mulching

Vertical Mulching

The first is vertical mulching, in which the technician removes soil in small bursts radiating outward from the trunk and extending the entire drip-line of the tree. The small but 8-12 inch deep cavities are then replaced with a porous and nutrient-rich compost blend. The result is a looser, more aerated soil structure for new roots and beneficial microorganisms to expand into. This service can be provided almost year-round (frozen ground/drought excluded) and is my go-to for mature trees on undisturbed sites that are beginning to lack vigor.

Radial Trenching

Radial Trenching

One step up, radial trenching is a similar procedure, but instead of small bursts, the soil is removed in continuous lines radiating outward the length of the canopy. I prefer this technique for new builds and areas with recent compaction, urban sites, and situations where old trees are beginning to decline. This is another almost year-round service.

Root zone Invigoration

The most extensive of entire root zone services we offer is root zone invigoration. In this technique, we use the air spade to remove all the grass, soil, or competing plants sitting on top of the tree's root system. We then correct any girdling and planting depth problems. Finally, we replace the entire space with our compost blend. This is a big, messy, expensive procedure but often the best solution when a valued small to medium-sized tree is being damaged by mowers, vandalism, or when there is an especially dense or aggressive plant growing above the root zone. I prefer this service to occur during winter dormancy, but in extreme cases, it can be performed any time roots are too restricted to function properly.

It’s easy to forget about your trees while they're sitting leafless in winter - but this can be the most beneficial time to give them attention. Caring for your tree's roots is often more beneficial than pruning, spraying fungicides, or almost any other plant health care service.

Sincerely,

Mitch Lippencott I Regional Manager, Russell Tree Experts

Mitchell Lippencott joined Russell Tree Experts in 2020 and has been in the green industry for over 20+ years with a diverse background ranging from working for a landscape design company, a retail garden center, and two municipalities! Mitch is an alum from The Ohio State University, a licensed pesticide applicator, a qualified tree risk assessor, and an ISA certified arborist. Outside of work, he enjoys traveling, cooking, and gardening.

Root for YOUR Tree and Learn More BELOW!

Tree Work in the Winter?

Dear Reader,

“Can we get this work scheduled before winter kicks in?” “Do you complete tree work during the winter?” These are questions that I am often asked as the hibernal or winter soltice has arrived. In many cases, winter is the only time we can complete certain projects. This is due to the fact that many diseases and insects are not active, wildlife regulations are not in effect, visibility is increased, and the impact on landscapes is lessened due to winter’s colder conditions. Winter can be the perfect time for tree work.

One example of projects that must be completed during the winter is anything that falls under federal bat tree regulations. This typically includes public property projects where large trees need to be removed or the removal of any tree that could be a nesting site for bats. These regulations are intended to protect the Indiana Bat and the Northern Long-eared Bat, which are both currently endangered species. The importance of bats in our ecosystem is a story in itself. Bats typically overwinter in caves but move out to their nesting sites as early as April, therefore removal of possible nesting sites is regulated from March 31 through October 1. This is the main reason that the majority of our clearing operations and trail creation projects are completed during the winter months.

Winter is also also an opportune time for tree pruning to minimize the risk of insect and disease issues. For oak trees and elm trees, oak wilt and Dutch elm disease respectively are two devastating diseases that are be transmitted by insects (and root grafts) attracted to fresh pruning cuts. (Learn more here!) These insects are typically not active during the winter months, thus making approximately October 15th to March 31st the preferred time to prune oak and elm trees. If pruning cuts are required outside of this time window due to reasons such as storm damage, we highly recommend painting the cuts to minimize the risk of attracting the insects that can spread these diseases. Other trees that can benefit from winter pruning is the Rosaceae family which includes apples, pears, plums, and other fruit-bearing trees. The pathogens that infect many of these trees with diseases such as fire blight and black knot are typically not active during the winter months. Black knot is also much easier to see and prune out when the leaves are not present on our plum trees. Sanitation between cuts and proper disposal of these branches is imperative to slow down the spread of this disease.

Another reason for performing tree work during the winter months is the minimization of turf impact. Winter typically provides an absence of perennial and annual plants that are often planted under trees. Clients also tend to store their yard art, furniture, and other items that could be damaged during pruning and removal operations. This allows for our crews to be more efficient as less time is spent preparing the drop zone and moving items to a safe location prior to beginning any tree work. Thirdly, the winter months tend to be colder which provides a harder, sturdier ground that is more resilient to damage from limbs or equipment. As always, we do place mats on the ground if turf impact is a concern regardless of the time of year. Therefore, winter pruning becomes much more productive since there are fewer items that could be damaged otherwise.

Certain job sites such as golf courses, public parks, and street tree pruning, just to name a few, are performed during the winter months as there tends to be less pedestrians, allowing for better focus, less interference, minimized risk, and overall a more efficient and safe work zone.

As you can see, there are many reasons for scheduling a visit from your ISA certified regional manager this winter. With the absence of leaves on the trees, it is much easier for the trained eye to identify structural issues. Some structural issues may require a cable or even brace rods to secure your favorite tree in your landscape. Winter is also a great time to observe decay, fungi, or other pathogens that may not be visible during the summer when leaves are abundant and present. It is also the best time to observe cavities throughout the tree that may not be noticed while leaves are present. Dead, diseased, and broken branches are also much more visible when the leaves are not present in the winter months. Our arborists are trained to be able to identify the difference between dead and live branches even during the winter months. This time also allows the arborist to make quick decisions on improving the structure of the tree while pruning in the most efficient time of the year. Every day is a good day for tree care! Check out the video below to learn more!

Sincerely,

Mike McKee | Regional Manager, Russell Tree Experts

Mike graduated from Hocking College in 1983 with a degree in Natural Resources specializing in urban tree care. He has been a certified arborist since 1991. Mike started his career in the private industry in 1985 before becoming a municipal arborist in 1989. He retired after serving thirty years before joining us at Russell Tree Experts in Sept. of 2018. His love of trees has never waned since trying to climb up the ridges of the massive Cottonwood tree in front of his childhood home.

10 Boxwood Alternatives

Dear Reader,

My introduction into the horticultural world was working at a small retail nursery in the early 2000s. Back then, when a customer would ask for an easy to grow, low maintenance, no brainer plant, boxwood is what we would often recommend. Fast forward twenty years and today boxwood have to contend with boxwood leaf miner, boxwood psyllid, spider mites, volutella stem canker, winterburn, boxwood blight and most recently, a new disease known as boxwood dieback. Historically, Boxwood have been appreciated in the landscape because they are evergreen, deer proof, compact, easy to manipulate and respond well to pruning/shearing. But they are no longer the maintenance free, easy to grow plants they once were. 2023 was a particularly bad year for boxwood in central Ohio and every arborist, landscaper and plant person I know was overwhelmed with calls from desperate clients willing to try anything to restore their boxwood to how they once looked. Many of the boxwood installations I observed this year are beyond preservation. Others will likely recover over the next two to three growing seasons but may look a little rough along the way. Much of the damage that occurred to boxwood this year is a result of the cold weather event we had just before the holiday season of 2022, where temperatures changed from 40 degrees Fahrenheit into the negatives in less than 12 hours. There is no topical spray or any professional service that can be offered to combat this sort of environmental event. And many of the boxwood that were able to survive the initial cold temperatures succumbed later to disease spreading pathogens seeking a stressed and vulnerable host. Even under normal weather conditions, most boxwood require regular applications of insecticides and dormant oils to protect them from insect pests that have taken advantage of their abundance. The best management strategy for the prevention of disease and insect pests on our plants is to use plants that do not get those diseases and insect pests. So as you are wrapping up your Fall landscape plantings or making plans for next Spring, consider something new for your hedges, accent plants and foundation plantings. Here are 10 suggestions for plants to consider with similar characteristics to boxwood.

1. Blue Holly

Blue holly (Ilex x meserveae) is a hybrid between the cold hardy Asian prostrate holly (Ilex rugosa) and English holly (Ilex aquifolium). It is one of my personal favorite evergreen shrubs and has lustrous dark green/blue leaves and dark red berries on female plants that ultimately feed the robins and mockingbirds around late winter to early spring. Individual plants form a shrubby upright to pyramidal habit and can grow 8 to 12 feet in height by 6 to 8 feet in width. Blue holly (Ilex x meserveae) can easily be pruned into hedges and can be kept at any height or width with minimal, annual pruning. They are cold hardy to -20 degrees Fahrenheit and adaptable to both full sun or partial shade. Several cultivated varieties of this hybrid exist with my personal favorites being Blue Princess and Blue Prince.

NOTE:  Holly plants require a male pollinator to achieve fruit. Make sure to include at least one male plant (like Blue Prince), and possibly more depending on the size of your Holly plantings to improve fruiting.

Negatives: Blue holly (Ilex x meserveae) can have significant leaf burn when temperatures drop below -10 degrees Fahrenheit (although established plants recover quickly in the Spring). They are susceptible to phytophthora (root rot) in poorly drained sites and deer browsing during the winter when snow persists for days at a time.

2. Privet

Privet (Ligustrum spp.) is a densely branched shrub with dark green to yellowish green leaves that can easily be manipulated into rounded plants and hedges. Privet (Ligustrum spp.) is fast growing and adaptable to a wide range of soils and growing conditions; I’ve observed many well kept privet hedges that would give boxwood a run for its money during the spring or summer. The foliage persists late into the fall often turning purple but is not evergreen. There are no serious disease or insect problems and oftentimes plants seem to thrive with neglect. Several different species and many different cultivars exist for a range of size, texture and leaf color.

Negatives: Privet (Ligustrum spp.) is not native to central Ohio and can easily spread by seed into native areas and out compete native species. They are also not evergreen.

3. Wintercreeper euonymus

Until recently I have always considered this species of euonymus to be best used as a ground cover or climber on a tree or trellis. More and more though, I’m seeing it in the landscape pruned into a very small and cute hedge or sculpted into 1 to 2 feet tall and wide mounds looking very similar to boxwood. Euonymus in general is fast growing and adaptable from full sun, to full shade, and to just about any landscape situation that isn’t a swamp. Leaves are evergreen most winters (leaf drop can occur when temps drop below -20 F) and there are dozens of cultivated varieties for leaf size and color. I’m partial to the green and white variegated cultivar ‘Emerald Gaiety.’

Negatives: Wintercreeper euonymus (Euonymus fortunei) is not native and can easily naturalize and take over unmanaged native areas. They can be susceptible to euonymus scale and difficult to treat successfully once a population is established.

4. Spirea

There are several species and dozens of different cultivars of spirea that mimic the compact and rounded habit of boxwood. They can be grown as separate plants, planted in masses or managed as a hedge. Spirea can grow in most landscape situations and will perform well in any soil that is not excessively wet. Spirea are easy to grow, have little insect or disease problems, respond well to pruning and shearing, and are cold hardy and adaptable to full sun and partial shade. Spirea are deciduous but even without leaves, the stems and twigs are so dense that the structure of the plant still provides texture and interest in the winter landscape.

Negatives: Spirea are not evergreen. They can get powdery mildew but it has little impact on the overall health of the plant. Spirea may also be somewhat overused in the landscape but for good reason - it is almost impossible to kill.

5. Japanese HollY

Japanese holly (Ilex crenata) is another compact evergreen shrub with a rounded habit and dark green foliage through the growing season and through the winter. They can grow 3 to 5 feet in height and width, although I have observed larger plants in arboreta. Japanese holly (Ilex crenata) is cold hardy to - 20 degrees Fahrenheit and adaptable to both full sun or partial shade. They respond well to pruning/shearing and can be used in hedges, foundation plantings, or in masses. Several different cultivars are available for different sizes, colors, and superior cold hardiness.

Negatives: Japanese holly (Ilex crenata) is slow growing and not tolerant of high pH soils. They are a preferred host to spider mites during extended periods of drought. Japanese holly (Ilex crenata) is not well known in Ohio and could be difficult to source. I would avoid using the upright cultivar ‘Sky pencil’ unless in a warmer protected spot with exceptionally well drained soil.

6. Globe arborvitae

Globe arborvitae (Thuja occidentalis ‘Globosa’ or ‘Little Gem’) is a compact and rounded form of our native eastern arborvitae. Its leaves are bright green in the spring and summer but turn more bronze or yellowish green during the winter months. Globosa arborvitae is a dwarf form and matures to only 5 to 6 feet tall and wide. They are very adaptable to different soil types and respond well to pruning and shearing. Globosa arborvitae can be used as a specimen plant or accent plant as well as in hedges or foundation plantings. Little gem arborvitae has essentially the same habit as globosa arborvitae but are smaller, maturing to a height of about only 3 feet tall. Either cultivar will perform well from full sun to partial shade (but they should have at least a half day of sunlight).

Negatives: Deer will eat arborvitae to bare wood when hungry. They are also a preferred host to bagworm and spider mites.

7. Yew

Yew (Taxus spp.) is a hardy and easy to grow evergreen shrub. I use them primarily for screening in the parts of my garden that receive less sun, but they can be easily manipulated and sculpted into tight hedges, mazes, and formal shapes in the same fashion that we often treat boxwood. Yew are very adaptable and urban tolerant and can withstand almost any amount of pruning. They will grow well in sun and shade and have few disease or pest problems. If they are used as an alternative to boxwood, I recommend the cultivars ‘Runyan’ or ‘Densiformis’.

Negatives: Yew are susceptible to deer browsing

8. Japanese Plum Yew 

Japanese plum yew (Cephalotaxus harringtonia) is similar to yew, but with longer and glossier needles. I have planted this in more than one rural location and my experience so far is that deer will not touch them. Japanese plum yew (Cephalotaxus harringtonia) should be considered by anyone that likes yew but has given up because of continual deer damage. There are several different cultivars selected for a range of different sizes and habits but ‘Duke Gardens’ is the cultivar I recommend for central Ohio gardens and for anyone wishing to experiment with using Japanese plum yew (Cephalotaxus harringtonia) to replace boxwood. This cultivar matures to approximately 2 to 3 feet in height, approximately 3 to 4 feet in width and is cold hardy to - 20 degree fahrenheit.  There are no serious pest or disease problems.

Negatives: Straight species is not cold hardy in true zone 5 winters (winters that reach -20 F). I observed significant winterburn in the plants in my garden from the cold snap we had just before the holiday season of 2022.

9. Inkberry 

This is one of the boxwood alternatives that I think has the most potential. Inkberry (Ilex glabra) is native to the east coastal plains of the US and is a compact evergreen shrub with lustrous, dark green leaves during the growing season. Foliage can bronze somewhat during the winter months. Without pruning, inkberry (Ilex glabra) can reach heights of 6 to 8 feet tall with a width of 8 to 10 feet wide. Female plants can produce a small, pea-sized black berry (hence the name inkberry) that is edible to birds. Inkberry (Ilex glabra) performs well from full sun to full shade (foliage density is better with at least 5 to 6 hours of sunlight) and is cold hardy to - 20 degrees fahrenheit; although I have observed winterburn in exposed plants during winters with temperatures that have dropped below zero for extended periods of time. Inkberry (Ilex glabra) responds quite well to heavy pruning or shearing and has strong regenerative growth in established plants. They can easily be used as individual specimen plants or in hedges. I recommend using the cultivars ‘Cape Cod’ or ‘Compacta’ if available. These selections maintain a more rounded and compact habit with less pruning.

Negatives: Inkberry (Ilex glabra) is not tolerant of excessively high pH soils and plants can lose lower leaves and become quite leggy if not well managed. I have observed significant deer browsing during periods of extended snow cover in landscapes with a high deer population.

10. Canadian Hemlock

Canadian hemlock (Tsuga canadensis) is one of my favorite evergreen trees. It is a native and graceful evergreen tree with glossy dark green needles that also responds well to aggressive pruning. When my wife and I moved into our current home in 2008, we planted 36 Canadian hemlock (Tsuga canadensis) on 5 foot centers around the perimeter of our front and side yards. We keep these plants sculpted into a tight 6 feet tall by 3 feet wide pyramidal shaped hedge which we prune once a year in the late spring, approximately a month after new growth has pushed out. This could make an excellent replacement for a tall boxwood hedge.

Negatives: Canadian hemlock (Tsuga canadensis) is susceptible to deer browsing during the winter months with extended periods of snow. They are a preferred host to spruce spider mites when under stress. Canadian hemlock (Tsuga canadensis) also have poor tolerance to drought.

These 10 plants are just the beginning of the conversation regarding boxwood alternatives. There are dozens of other cultivated varieties of chamaecyparis, juniper, spruce, pine, fir, leucothoe, etc that could fulfill the same niche in many of our gardens. I believe there is a perfect substitute out there for every plant. The perfect substitute for your needs will depend on your individual situation and landscape.

Sincerely,

TJ Nagel I Scheduling Production Manager, Russell Tree Experts

TJ loves trees. He is an avid gardener and plant collector. TJ graduated from The Ohio State University with a B.S. in Agriculture with a major in Landscape Horticulture and minor in Entomology. TJ is an ISA Board Certified Master Arborist and well versed in Plant Pathology. TJ joined Russell Tree Experts in 2012.

Illustrations by Kenny Greer, Russell Tree Experts

The Year of the Ugly Boxwood

Dear Reader, 

My good friend and arborist colleague Cat Baumgartner wrote the below article for the Inniswood Garden Society’s quarterly member newsletter (known as The Image). As soon as I read it, I knew that I wanted to share it with all our readers. Cat does a thorough job of describing the most serious problems we have had with boxwood this year and she explains them well and in simple terms. She has generously agreed to let us republish it. Photos within the body of Cat’s article are courtesy of Joe Boggs, OSU extension educator for Hamilton County.

- TJ Nagel, Russell Tree Experts

---

The Year of The
Ugly Boxwood

by cat Baumgartner, Oakland Nursery

I don’t have a simple answer. Or there are multiple answers, and your boxwood might have one, or several of the problems at once.

I’ll go over the likely suspects for this year- including winter damage, or ‘winter burn’, Boxwood Leafminer, Volutella Blight, and THE Boxwood Blight.

I’ll start with winter burn. Boxwood store a lot of their energy in their leaves through the winter. When we get extreme cold and wind in the winter, the leaves will lose more moisture. If the ground is frozen or dry (or worse, both), the leaves lose moisture faster than the roots can replace it, and we get the ‘burn’, where they turn a straw color and die, staying attached to the stem. It wasn’t noticeable until early spring, because evergreens have a delayed reaction to stress. It’s why we can cut down trees for Christmas and they don’t immediately turn brown, often lasting months. We did have greater than normal rainfall last year, but the three months leading up to late December were on the dry side. So, the ground was dry leading up to the extreme cold event that hit in late December creating a Double Whammy. There was a lot more winter burn this spring than I’ve seen in decades. It looks like straw-colored sections in the shrubs, often in a random pattern.

Photo courtesy of Joe Boggs, OSU extension educator for Hamilton County. 

Next, there are different blights out there that can affect boxwood. ‘Blight’ is a general term for a plant disease, typically caused by a type of fungus. Most of them are less common and less damaging than the blight striking fear in the hearts of gardeners that is Calonectria pseudonaviculata, called simply “Boxwood Blight”. There have been some isolated cases in the Greater Columbus area. The main symptom though is defoliation. You’ll have green leaves, then they’ll start looking funny, and rapidly progress and fall off the stem. In a matter of weeks, you can go from a healthy-looking plant to one with sections with completely naked stems. Definitive identification requires lab testing. Other blights can show similar symptoms, but since some are more treatable, confirming which type of blight your boxwood might have is recommended before removing plants. If you do have “Boxwood Blight,” replanting with more boxwood is not recommended, so confirmation of what kind of blight you have will also tell you what you can plant in that spot. Most of the damage we’ve been seeing is NOT “Boxwood Blight.”

Photo courtesy of Joe Boggs, OSU extension educator for Hamilton County. 

Volutella Blight or Pseudonectria Canker (Pseudonectria buxi) can be damaging but is not necessarily a death sentence often just affecting individual stems and not whole portions of the plant. Symptoms can be seen if the stem is sliced into, showing dark brown streaking just under the bark. Most twigs infected with Volutella blight will turn straw colored and die. In most cases dead stems from Volutella canker can be easily pruned out and the remaining portions of the boxwood will fill in slowly over time. 

This year we also had frost damage in May. If leaf buds are still tight, frost is not a problem. If the new leaves have emerged, but have ‘hardened off’, it is also not a problem. But if the new growth is timed so that it is new, fresh and tender, and then we have a late freeze, the new growth is damaged, turns that sad straw color, and is aesthetically at least, a problem. A healthy shrub can put out another round of growth, and it is not a long-term problem. Trimming off the burnt new growth is all that needs doing.

Photo courtesy of Joe Boggs, OSU extension educator for Hamilton County. 

Boxwood Leafminer, an insect pest, is an ongoing problem. The damage from leaf miner is more generalized, an ‘all-over’ bad look rather than the chunky sections dying back. The adults lay eggs in the new growth in mid-spring, and as the larval stage hatches and begins to feed on the interior tissues, the leaves start looking bad, often having a blistered or bubbled effect, usually easier to see from the bottom of the leaf.   

Preventative sprays can thwart adult leafminers from laying eggs in the new growth, but need to be applied as you see the new growth. Systemics applied in the Fall or Spring can also provide control but know that boxwoods are insect pollinated. 

If you don’t have Boxwood blight, you have two options. Cut out the dead branches and let the plants regrow which may take three years or more to totally restore, in good condition, or replace the plants.

---

A Final Note…

Since Cat wrote her article, we have had several boxwood shrubs test positive for yet another disease, Colletotrichum theobromicola (also referred to as boxwood dieback). This is a new disease for central Ohio and symptoms look similar to other blight diseases with the random dieback of twigs and straw-colored foliage. However, in addition to twig dieback, the pathogen also causes leaf spots that appear white in the center surrounded by dark brown margins as well as a bright black discoloration just beneath the bark along the twigs. The jury is still out on the best way to attempt to manage this disease but for now, good cultural practices such as removing symptomatic plants and sterilizing pruning tools between pruning different plants are the best-known strategies. Fungicides might also be helpful, but efficacy has not been determined. Laboratory testing should be used to confirm boxwood dieback because it can easily be misdiagnosed as other blight diseases. 

View fullsize

Twig Dieback (Colletotrichum theobromicola)

View fullsize

Leaf Spotting (Colletotrichum theobromicola)

As we continue to have more problems in the landscape with boxwood, it may be time to consider alternative plants that can achieve a similar function. Stay tuned for my boxwood replacement article later this Fall.

Sincerely,

TJ Nagel I Scheduling Production Manager, Russell Tree Experts

TJ loves trees. He is an avid gardener and plant collector. TJ graduated from The Ohio State University with a B.S. in Agriculture with a major in Landscape Horticulture and minor in Entomology. TJ is an ISA Board Certified Master Arborist and well versed in Plant Pathology. TJ joined Russell Tree Experts in 2012.

Anatomical Upgrades for Your Trees!

When you think of anatomy, what comes to mind? I think of humans specifically, and learning about the wonderful bone and organ systems in our body in middle school science class. You may think about the anatomy of various animals and how there is an abundance of variety depending on where you are in the world, but how often do we consider the anatomy of trees?

Surely trees are just trees, right? They grow without us even considering how or why they may grow in the ways that they do. We may be blissfully unaware of their anatomy or structure until we are confronted by the reality of a winter ice storm or a summer thunderstorm. Oftentimes, we may find trees with less-than-desirable structure having taken damage after these events, or worse, having caused property damage along with their own demise!

Two examples of trees with codominant stems

You may be asking yourself, what does poor tree anatomy look like? The answer to that question deserves its own article, however a majority of tree structural problems can be narrowed down to codominance, and that is what I want to address in this article. Codominance is when a tree has two or more similarly-sized trunks emerging from the same location and forming a distinct “V” shaped union. There are varying reasons as to why a tree may be codominant, and some species have natural habits that lend themselves to becoming codominant. 

Visual representation of codominance by Jacob Nau

To give you a visual representation of codominance, bring your elbows together in front of your chest, with your palms facing you. Now, spread your wrists apart, keeping your elbows together to form a distinctive V shape. Opening up your fingers you can picture the crown of a tree. Seems like an awkward, weak position to be in, right? Now, imagine adding the weight of tree branches, leaves, rain and 15-50 mph wind gusts, etc. (trees can go through a lot!), while you strain to keep your elbows together, and you can begin to imagine why a codominant union (V-shaped union) in a tree is not anatomically advantageous.

So what can be done to fix, or even prevent, codominant structure in a tree? The answer to this question largely depends on the age of the tree. If your tree is young and generally under the age of approximately 20 years, then a structural pruning plan can be performed to help guide the tree out of its codominance over the next 5-10 years. 

However, if your tree is large and mature, there are a number of services that can be used to help support your tree's anatomy. Those services include:

End-Weight Reductions

• Reduce the length of long, lateral branches in the tree’s crown to reduce the weight and levering effect on the codominant union below. Typically performed before or with a cabling support system.

Jacob Nau performing an end-weight reduction on a tree.

Cabling Support System

• Install a single, or multiple, static steel cable(s), or dynamic rope cable(s) in the tree’s crown to support the codominant union below.

A static cabling system in a Hackberry tree in Clintonville, Ohio.

Through-Brace Support System

• Install a system of steel threaded rods into the codominant union to strengthen that area of the trunk. This is usually performed in-tandem with a cabling support system.

Top Left: Final result of a brace rod installation. Top Right: Close-up of a singular, installed brace rod. Bottom Left: Side profile of two installed brace rods. Bottom Right: A brace rod about to be inserted.

Propping Support System

• Install a single, or multiple, semi-permanent wood prop(s) to support a lower, large lateral limb to ease the strain on a codominant union. This is a more unique way to support the tree's anatomy, specifically for low, long, and lateral limbs that are difficult to support with a cabling system.

A tree prop supporting a limb from the Angel Oak tree in South Carolina.

All of the services listed above, including the young-tree structural pruning, are services we perform at Russell Tree Experts. I highly encourage you to look out your window and consider your tree's anatomy! Can they be supported? Is it time for an anatomical upgrade? If so, give our local office a call at (614) 895-7000 and we will happily connect you with one of our Regional Managers to assist you in determining the best course of action for your trees!

Sincerely,

Jacob Nau I Training and Development Manager, Russell Tree Experts

Jacob is an ISA certified arborist and joined RTE in 2018. He has been involved in tree care for over 10 years. He enjoys climbing trees both recreationally and professionally and in his free time, he loves spending time with his family.

Magnolia Scale: They're Back!

By Mike McKee
ISA Certified Arborist®
June 20, 2024​

Hello! We have decided to revisit the topic of magnolia scale and add more information to this previously published article as we are in the middle of a larger magnolia scale infestation compared to last year (2023).

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

Please note: This article was originally published on 8/9/2023 and was revised and republished on 6/20/2024.

Is your magnolia tree turning black? Is it attracting ants, flies, bees and wasps? Is there a sticky substance covering the leaves and everything under the plant? If you look closely, you will also see white blotches on the twigs throughout the tree.

This is an invasion of magnolia scale like we have not seen in several years. They happen to thrive in warm summers with abundant moisture. The population is building and is very apparent this year.

The insect overwinters on twigs and is inconspicuous to the untrained eye until it starts feeding and producing honeydew. Honeydew is the very sweet, sticky substance secreted by the insect that in turn coats the leaves and anything under the plant. This is what attracts other insects to the plant. Eventually the insect covers itself with a waxy coating that protects it while feeding. These are the white blotches we are now seeing on the plants starting early summer through August.

Nymphs emerging from a recently plucked adult Magnolia Scale

The juvenile stage of magnolia scale emerges from these waxy coatings (the adults) in mid to late August through September as crawlers. This is when scale are most vulnerable to insecticides and we attempt to control their population. We typically recommend 2 to 3 topical insecticide sprays during this period spaced a couple weeks apart for the best control of the insect due to the extended emergence. During seasons with larger infestations, it is unlikely that insecticide sprays will completely eliminate this insect. The overall goal of plant healthcare is to keep the population at a threshold that minimizes damage and maintains aesthetics of the host tree.

If the tree’s owner is concerned about the population of magnolia scale before the appropriate window for insecticide applications is open, there are a few DIY options that can be done. First, the insects can be scrubbed off from branches and leaves in June and July. This is when the adults are visible before the hatch begins. You could also prune out heavily infested Interior branches to help reduce numbers. Be sure to completely dispose of any pruned branches as the insect will still hatch. Spraying the trees with a medium pressure garden hose can also eliminate some insects as well as reduce the honeydew on the plants.

The insects feed by sucking sap out of the tree. If left untreated the scale population can grow to levels that will cause decline and eventual death in your tree.

Another issue with Magnolia scale is the occurrence of sooty mold which is a byproduct of the honeydew produced by the scale. It is a black fungal growth which is what most people notice first. Although this generally does not harm the tree, it is very unsightly.

In closing, if you have a magnolia in the landscape, give us a call and we will dispatch a certified arborist to your property to come out and complete an evaluation of the tree and make recommendations for the best management strategy. Timing is everything.

Sincerely,

Mike McKee | Regional Manager, Russell Tree Experts

Mike graduated from Hocking College in 1983 with a degree in Natural Resources specializing in urban tree care. He has been a certified arborist since 1991. Mike started his career in the private industry in 1985 before becoming a municipal arborist in 1989. He retired after serving thirty years before joining us at Russell Tree Experts in Sept. of 2018. His love of trees has never waned since trying to climb up the ridges of the massive Cottonwood tree in front of his childhood home.

How to Mulch Around a Tree

Dear Readers,

Mulching is an important aspect of tree maintenance that is both functional and decorative, adding to your tree’s lifespan and helping it look its best. The main benefits of tree mulching are that it deters weeds, improves soil quality, protects trees from lawnmower damage, insulates soil from extreme temperatures, and retains moisture during hot weather. Today, I would like to talk about some tips and tricks on how to properly mulch a tree. At the top of this article is an instructional video hosted by ISA Certified Arborist Lindsey Rice that can be used to follow along while mulching your own tree!

Example of a properly mulched tree

To mulch a tree, you will need organic wood chip mulch, a shovel, a rake, and personal protective equipment such as safety glasses, gloves, and boots. A wheelbarrow or air spade may potentially be needed depending on the situation. The best time to mulch a tree is in the fall or spring. Many trees are incorrectly mulched when the mulch is too high or when it covers the root collar of the tree, which is where the trunk and roots meet. The mulch only needs to be 1 to 2 inches deep and the root collar should be completely exposed in order to properly receive oxygen. This will help prevent girdling roots, which are roots that wrap around the trunk in search of oxygen. This can suffocate a tree and add unnecessary stress. If your tree has girdling roots or a mulch volcano, you will need to resolve these issues prior to mulching.

Example of a “mulch volcano”

Example of girdling roots

If there are no girdling roots, the first step is to pull out any weeds surrounding the base of the tree. Then, you may begin applying mulch in a wide and evenly spread area. For younger trees, it is ideal to mulch all the way out to the canopy drip line, which is where the majority of a tree’s roots extend, but you may have to compromise depending on your landscape.

Example of a canopy drip line

For older trees, this is not as important. You should still see similar results when bringing the mulch out about 3 to 5 feet from the base. You can use a rake, shovel, or your hands to evenly distribute the mulch. The mulch only has to be about 1 to 2 inches deep at most, so make sure you avoid mounding, Leave about 2 to 3 inches of space between the mulch and the root collar in order for the tree to properly receive oxygen and to prevent girdling roots. This will also help prevent any moisture issues, which can lead to disease and rotting. Afterwards, you are all set!

For maintenance, water your mulch whenever it looks dry. Ohio can have inconsistent weather, so there is no need to water it on a scheduled basis. Also, only add mulch whenever it is looking sparse and below that 1 to 2 inch needed depth. Make sure you break up, turn over, and mix in the old mulch to prolong the mulch’s lifespan, prevent any clumping, and to allow maximum movement of oxygen and water. If there are any questions, please feel free to leave them in the comments section below and be sure to watch ISA Certified Arborist Lindsey Rice’s video for a visual guide on this topic! Good luck on your next mulching project!

Additional Reads!

Below are two excellent articles written by our ISA Certified Arborists related to mulch volcanoes and girdling roots.

”Mulch Mounds! Oh My!”
by ISA Board Certified Master Arborist José Fernández

“Are Your Trees Being Suffocated By Their Own Roots?”
by ISA Certified Arborist Chris Gill

Enrique Arayata I Video Production Assistant, Russell Tree Experts

Enrique is a third year student at The Ohio State University majoring in moving image production with a double minor in photography and film studies. In his free time, he enjoys running, spending time with his girlfriend and family, photography, and creating YouTube videos.