Another installment in our series of posts where Texas Tree Surgeons answers your tree questions. Are you having problems with your trees and want to know what’s wrong? Let us know!

Dear Texas Tree Surgeons,

A lot of my bushes, especially the red tip photinias, are starting to wilt and have reddish-brown spots on their leaves. What can I do about that?

Red Tip Photinias have long been a staple of North Texas flowerbeds and hedgerows. Hardy and fast-growing, the evergreen shrub can be trimmed to various heights and forms a good privacy barrier with its broad leaves. New growth has red leaves, giving the red tip photinia its name. Unfortunately, red tip photinias are particularly susceptible to leaf spot diseases.

This fungus Entomosporium mespili causes leaf spot on all members of the rose family, including red tip photinias. Starting as a red, brown, or black dot on leaves, the leaf spot expands outward as the fungus grows. Eventually, the red spots turn into a gray area rimmed by red. As the fungus spreads, it disrupts vascular function in the leaves, which eventually fall. The fallen leaves collect moisture at the base of the shrub, increasing fungal growth. As wet conditions continue, the fungus can spread its spores within water droplets, such as splashing from rain or irrigation. Left unaddressed, the fungus will spread throughout the photinias, causing wilting and dieback.

Environmental control

The first line of defense against fungal leaf spot, as with many fungal diseases, is to monitor watering and drainage. Fungi thrive in wet conditions of a moderate temperature, so the spring and fall are when we see the most activity. In periods of wet weather, the clay soil common to much of North Texas can hamper proper drainage, causing the area around the red tip photinias to become waterlogged. This moisture, mixed with the fallen and decaying organic material creates the ideal conditions for fungal growth. Even if the soil drainage cannot be improved, it is important to curtail watering so as not to make the situation worse.

In addition to moisture, the fallen photinia leaves contribute to the growth of the Entomosporium fungus. Keeping the area around the plants clear of debris can help slow fungal progression. In a similar way, dense foliar growth on the interior of the red tip photinias can collect moisture. Where possible, thin out dense areas to allow light and air to circulate. When trimming, make sure to remove any areas already showing leaf spot. Removed material, especially infected leaves, should be buried or disposed of in a plastic bag.

Chemical Control

Fungicides can be used to control Entomosporium leaf spot, but the process can be costly. Furthermore, treatment will be ultimately ineffective if the environmental factors are not eliminated. For valuable hedges, a continuous process of multiple-week treatments in the spring and fall may be recommended. In other situations, it can often be more cost-effective and better in the long-term to remove the affected plants and replace with a less-susceptible species. 

While there is no quick solution for red tip photinia leaf spot, we hope this information can help homeowners mitigate the damage to their shrubs, and decide if treatment or removal might be warranted. At Texas Tree Surgeons, we love trees (and shrubs! and hedges!) and we love our customers, and we always want to give our community the best, most accurate information regarding their plants. If you would like one of our arborists to come out and see how your photinias, or anything else, are doing, let us know!

When people talk about tree care, they can use different words to talk about the same thing. You may hear “trim,” “prune,” or “cut,” just as you may hear “limb” or “branch.” At Texas Tree Surgeons, we are often asked the difference between a branch and a limb, or between tree pruning and tree cutting. Unfortunately, there is no industry standard definition for many common terms, and that can cause confusion.

A NOTE

If you visit our Facebook page, you may notice that we are categorized as a “tree cutting” business. In other places, we may be listed as “landscaping services.” Unfortunately, because there is no universal standard term for what we do, we have to find the best fit under the circumstances. At Texas Tree Surgeons, we use the term “tree trimming” to refer to the work we do.

Proper Tree Trimming Is the Key to Healthy Trees

Trees are living organisms, and every cut that’s made on a tree has long-term effects. Additionally, every tree is unique and has different needs dictated by its environment and history. A heavy trim may have no adverse effects on a large, healthy tree, but a tree that is under pre-existing stress or has a potential for health issues might be irreparably damaged by removing too much canopy. Furthermore, safety and stability issues may restrict the amount and type of trimming that can be performed. It is important when trimming trees to take all of these factors into account, as well as to be mindful of the weather and seasons. Improperly trimming a tree at the wrong type of year can lead to severe decline and death. 

While there are no universal standards for tree trimming, there are two sets of guidelines for the tree service industry that we at Texas Tree Surgeons follow. The first is from the International Society of Arboriculture, or ISA. The ISA is the premier international credentialing and membership organization for the tree care industry. In addition to establishing the Certified Arborist and Board Certified Master Arborist credentials, the ISA provides a wealth of resources for tree owners. The ISA guide to tree trimming (they use the term “pruning”) covers the basics of how to properly maintain mature trees. In addition to the ISA, the Tree Care Industry Association (TCIA) oversees tree service providers in the United States. In collaboration with the American National Safety Institute (ANSI), the TCIA has developed comprehensive guidelines for tree care and management. These guidelines provide the basis for all of our work proposals and trimming. Adherence to these guidelines is the best way to care for trees of all kinds, and all our certified arborists are equipped to assess individual trees and determine the best — and healthiest — way to care for them. 

Trimming visible growth is only part of tree care. Without a proper understanding of what’s happening below the ground and underneath the bark, a beautiful trim is of little use. Certified Arborists are trained to spot the signs of environmental stressors, diseases, and insects. Poor drainage and soil condition, competition with turf grass, and proximity to structures can all affect a tree’s growth. Beyond just trimming a tree, certified arborists are able to evaluate the tree holistically in order to provide the best care possible. 

Whether It’s “Tree Trimming” or “Tree Cutting,” Cheaper Isn’t Always Better

Ultimately, what is important is the tree care itself, not what it is called. To give your trees the best chance to grow and thrive, look for tree trimming companies that employ certified arborists. If you have any doubts, ask for their certification number, or look for the arborist’s name on the ISA website. A properly-trained arborist should never recommend topping or lion-tailing, and should take proper precautions during oak wilt season (February-July). Never be afraid to get a second opinion. Give us a call anytime, and we are happy to have a certified arborist come out and discuss what work needs to be done and provide a free quote!

At Texas Tree Surgeons, we love trees and we love our customers, and we believe that educating our community lays the best foundation for caring for our urban forest. If you have any tree questions don’t hesitate to get in touch!

As we prepare for storm season, Texas Tree Surgeons has a few tips for taking the best care of your trees. Let us know if you have questions or need us to come out to assess your trees!

Consult a Certified Arborist to Assess Any Storm Damage

Storms, especially ones with high winds and hail, can cause extensive damage to trees. After the storm, it is important to remove any damaged or fallen limbs, and to clean up the wounds from damage. If the tree is at risk for oak wilt or other diseases, it is critical to clean up wounds and seal cuts. See our post on storm damage.

Water and Fertilize After the Storms Have Passed

After any flooding has receeded, and the ground returns to its usual moisture levels, it is important to begin a water regimen for damaged trees. Damage to tree tissue can reduce the tree’s ability to pull water and nutrients from the soil. Additionally, consider fertilizer to increase availability of nutrients in the soil.

Special Note About Hail

Hail can defoliate trees and cause damage to the outer layers of tree bark. The loss of leaves and damage to vascular tissue can severely limit the tree’s ability to use nutrients. Healthy trees can recover, but trees with underlying issues or stressors may have a hard time bouncing back.

Watch for Signs of Stress

Just like after construction, it can take weeks or months for trees to show signs of stress from storm damage. Yellowing leaves, dieback, and limb discoloration are some signs of stress. If you see any of these signs, or have any other questions about your tree’s health, consult a certified arborist.

At Texas Tree Surgeons, we love trees and we love our customers, and we want to help our beautiful North Texas trees weather any storms that may come. As always, let us know if you have any questions or would like a visit from a certified arborist — storm damage or not.

Is mulch really that important? As discussed in our article on proper mulching, there is a big difference between urban soil and trees’ natural habitat. Mulching can greatly improve the quality of soil around a tree, but it is not always possible to properly mulch around every tree. In those cases, or when faster results are desired, fertilizers can be used to increase the nutrient content of soil to better enable a tree to thrive.

Why Do My Trees Need Fertilizer?

For most of North Texas, our urban soil is a dark-gray or black alkaline clay. This type of soil is prone to compaction, and often cracks during long dry spells. Furthermore, much of the area sits on relatively shallow limestone bedrock. These conditions create a high competition for nutrients in the top layer of soil, as roots may be unable to grow deeper due to compaction and rock.

A note about tree roots:

Generally, tree roots serve two main functions: absorbing nutrients and providing stability. The stabilizing roots are the ones people most often think of, as they are usually larger than the feeding roots and can grow deep into the ground. The feeding roots, on the other hand, are finer and are primarily located in the top several inches of soil, where the most nutrients are usually found. So, when providing nutrients to a tree, it is critical to fertilize the shallow feeding roots, and less so to reach the deeper stabilizing root system.

Proper mulching and using compost to improve the soil condition are key to providing trees with an environment in which they can thrive. Most trees and shrubs would also benefit from fertilization, especially when in competition with turf grass, or when there is inorganic material surrounding a tree that prevents nutrients from reaching the soil.

What is the Best Way to Fertilize Trees?

A note about synthetic turf:

The use of synthetic turf around a tree can prevent proper soil development and make fertilizer difficult to apply. Usually, the synthetic turf needs to be pulled back from the root zone of the tree to allow for a soil drench, or the deep-root feeder rod will have to puncture through the turf and any substrate to reach the real soil. Additionally, synthetic turf can have lasting negative effects on trees, as the material prevents nutrients from reaching the soil.

In certain cases, direct application of a liquid fertilizer to a tree might be used. Using a foliar spray can make nutrients immediately available to leaves to aid photosynthesis. Trunk injections can introduce nutrients directly into the tree’s vascular system, bypassing the roots. These two methods are not long-term solutions, however, as they do nothing to improve soil quality. Once the applied fertilizer has been utilized, the tree will return to its previous state if a consistent supply of nutrients is not provided.

What Kind of Fertilizer is Best for Trees?

While there are many commercially-available fertilizers, they are not all equally effective, and care should be taken before applying. Fertilizers engineered for turf grass development may not help trees, and may, in fact, harm them. So-called “weed and feed” fertilizers contain herbicides that can target woody-stem plants. If applied in the root zone of a tree or shrub, these herbicides can cause stress or even dieback.

Subsurface application of dry fertilizers, including the use of fertilizer spikes, is usually inadvisable. Even when properly watered, pockets of fertilizer material or spikes do not readily break down, and cannot effectively move through the soil. As a result, the soil develops areas of high chemical concentration surrounded by areas that lack nutrients. This chemical imbalance can lead to severe fertilizer burn and can cause more harm than good.

Organic vs. Inorganic Fertilizer

Inorganic fertilizer is a solid or liquid product that is chemically formulated to add specific concentrations of nutrients to the soil. Inorganic fertilizers are generally labeled with three numbers (called “NPK” numbers), which indicate the relative content of nitrogen, phosphorous, and potassium, in that order. Inorganic fertilizers are used for their consistency and because they generally contain higher concentrations of NPK macronutrients than organic materials. However, because of the high percentages of certain chemicals, inorganic fertilizers are more likely to cause “fertilizer burn” because of over-saturation of a particular element. Furthermore, runoff from chemical fertilizers can contaminate water and pose a hazard to wildlife. Before using an inorganic fertilizer, it is important to understand exactly what the soil needs, and apply the appropriate amount. Soil testing, such as provided by Texas A&M, can give a guideline for selecting an inorganic fertilizer that is suited to a particular situation.

Organic fertilizers are composed of natural organic matter. While mulch and compost can be considered organic fertilizers, the term usually refers to a solid or liquid that is produced to be a soil amendment. Compost tea, bone meal, manure, and biosolids are common examples of organic fertilizers. Organic fertilizers can contain both macronutrients (usually nitrogen, phosphorous, and potassium, or “NPK”) and micronutrients, but the concentrations of these nutrients are not always specified on the label. Additionally, some organic fertilizers may contain helpful microorganisms (such as bacteria and fungi) that can further enhance soil quality. Because organic fertilizers are produced through natural processes, they generally have lower NPK concentrations than inorganic. As a result, organic fertilizers are less likely to cause fertilizer burn and do not pose the same risk to the environment as inorganics.

A note about compost:

Compost is partially-decomposed organic material that is added to soil to increase nutrient concentration. Like mulch, compost can improve overall soil composition, unlike fertilizers, which generally help plants, but do not have long-term effects on soil quality. Compost and mulch can be combined with soil amendments like fertilizers to help plants in the short-term and improve the soil over time. If you live in an urban area and don’t have the time or space to compost yourself, consider using a compost co-op. If you are in the Dallas area, we recommend Turn Compost. Check out their website to see if they service your neighborhood!

At Texas Tree Surgeons, we have three distinct fertilizer and soil amendment formulations that are applied in the Spring, Summer, and Fall. Each seasonal treatment is designed to give trees the nutrients they need at each stage of the growing season. We can also add specific micronutrients (such as iron) for particular trees. Contact one of our certified arborists to get an estimate for a year-round fertilization program!