What is dead and what is alive?
Is that branch dead or alive?
Fall has come and most or all the leaves are off your trees. A common question we hear is, how can you tell what is alive and what is dead? In short, the characteristics of dead branches are different than live branches. A deeper look will help you understand what we as arborist use as clues when deciding what to remove and what to keep.
The first major difference is visibility. When you are on the ground looking up at a tree branch 20 feet or higher in the canopy it may be difficult to see a lot of detail. As arborists, we look at trees all day long and have trained our eyes to recognize signs of dead branches from a distance. Our production crews are able to further distinguish dead from live branches because they are going to be accessing the canopy which means they won’t be 20 feet from the branch questioning its health, they will be right next to it, touching it, examining it. It is a lot easier to tell the health of a limb when it is in your hand than when it is far away.
As we begin to access the tree and work in it, the tree responds with movement. Dead branches move differently than live branches. If we are climbing the tree, our movement and the reaction by the tree is enough to identify where we need to focus our attention. When branches die they become less flexible and more brittle. Branch movement plays a major role in how trees deal with load (wind, rain, snow). The movement dissipates energy and results in less force that the tree needs to attenuate. Tree branches that don’t move are at a greater risk of breaking (i.e. dead branches fail more often than live ones). This also works in our favor for identifying dead branches. When a branch moves differently or moves less than the surrounding branches it is likely to be a dead branch.
When tree parts die they begin to breakdown by means of fungal decomposition. Ever see a mushroom growing on a tree? Mushrooms are the fruiting body of fungus. When mushrooms are visible on a branch it is likely dead or in some level of decay. As a word of caution when mushrooms appear on the trunk or around the base of a tree, you should have the tree looked at by an ISA certified arborist as soon as possible. When mushrooms are seen on branches it is a good sign the branch needs to be removed. Some mushrooms are very small and can be best identified while we are near them, working in the canopy.
Bark serves many purposes; retaining moisture content for the living tissue, regulating temperature, and protecting the inside of the tree from the outside elements, to name a few. When a branch dies the bark no longer serves a purpose and is eventually shed from the tree system. During this process bark may become discolored before it is shed. When we are close to dead branches, different color bark or missing bark is an easy clue that the branch is dead and needs to be removed.
Buds are the trees future branches, leaves, and flowers. When a branch has buds, seeds or leaves on it we can assume it is still functioning properly. If the buds are missing from a branch it is likely dead and can be removed. Buds on some trees are extremely small and hard to see, like the redbud or birch trees. Even healthy and live branches can be difficult to tell just looking at buds. However some species like oaks, ashes, and basswoods have large obvious buds that are easier to see. Again buds are easier to see when viewing branches up close.
Branches are green!? Well not at first sight. Bark is usually on a scale of grey but just under the bark exists a layer of chlorophyll filled, green, photosynthetic cells. This helps the tree produce energy for itself when it has no leaves. When a branch is dead it doesn’t maintain this layer and the green disappears. A scratch test can be performed on young branches and thin barked trees to look for evidence of health. With your fingernail, you can scratch the surface of the bark and if the resulting color underneath is green the branch is likely alive, if the under color is not green it may be dead. This test should be used infrequently as it does remove a small section of bark and can result in injury.
Using the above mentioned clues to assessing branch health, we as arborists are able to identify which branches are alive and dead even without leaves. This helps us maintain your trees all year long and reduce our dependency on removing deadwood only when trees are fully leafed out. In fact, some trees are best pruned in winter. Structural pruning and pruning trees with seasonal disease concerns should be addressed in the winter. If you think your tree has dead branches that should be removed, don’t wait until summer, winter maybe the best time.
John Wayne Farber
Certified Arborist WI-0877A
Hoppe Tree Service
Winter Tree Protection
Wisconsin’s harsh winter climate is often responsible for damage to landscape plants; native and non-native plants alike can be killed or injured during the winter. Cold temperatures can harm plants if winter conditions are severe or if plants have been stressed by the environment. Injury is more prevalent and more severe when low temperatures occur in early fall or late spring, when there is little or no snow cover during the winter or when low temperatures persist. With proper care, we can minimize these injuries and prolong the lives of our trees and shrubs.
Browning or discoloration of evergreen needles during winter occurs for a couple of reasons. Winter winds cause excessive transpiration (water loss in the needles) while the roots are frozen in the soil and unable to replace lost water. This results in desiccation and browning of the plant tissue. Bright, sunny days can warm the tissue above normal temperature which in turn initiates cellular activity. Then, when the sun is quickly shaded, foliage temperature drops rapidly and the foliage is injured or killed.
There are several ways to minimize winter injury to evergreens.
- It is important to wait until mid-spring before pruning out damaged foliage. Brown foliage is most likely dead, but the buds, which are more cold hardy than foliage, will often grow and fill in areas where brown foliage was removed. If the buds have not survived, prune dead branches back to living tissue.Avoid planting evergreens on south or southwest sides of buildings or in highly exposed (windy, sunny) places.
- Prop pine boughs or Christmas tree greens against or over evergreens to protect them from wind and sun and to catch more snow for natural protection.
- Construct a barrier of burlap or similar material on the south, southwest, and windward sides of evergreens.
It is important to wait until mid-spring before pruning out damaged foliage. Brown foliage is most likely dead, but the buds, which are more cold hardy than foliage, will often grow and fill in areas where brown foliage was removed. If the buds have not survived, prune dead branches back to living tissue.
Heavy snow and ice storms cause damage by bending and breaking branches. Trees with multiple leaders, such as arborvitae, juniper, and birch, are most subject to snow and ice damage. Trees can be wrapped together or the leaders tied with strips of carpet, strong cloth or nylon stockings two-thirds of the way above the weak crotches (illustration to right). These wrappings must be removed in spring to prevent girdling. Proper pruning by a professional arborist, to eliminate multiple leaders and weak branch attachments, will reduce snow and ice damage.
Deicing salt can cause or aggravate winter injury and dieback too. Salt runoff can injure roots and be absorbed by the plant, ultimately damaging the foliage. Salt spray from passing vehicles can also cause severe injury. To prevent salt damage, do not plant trees and shrubs in highly salted areas. Avoid areas where salty runoff collects or where salt spray is prevalent. Burlap barriers may provide protection to some plants from salt spray.
Mice, rabbits, and deer can all cause severe damage to plants in the winter. These animals feed on the tender twigs, bark, and foliage of landscape plants during the winter. They can girdle trees and shrubs and eat shrubs to the ground line. Deer can cause significant injury and breakage by rubbing their antlers on trees during the fall.
Trees can be protected from rodent damage by placing a cylinder of ¼-inch mesh hardware cloth around the trunk. The cylinder should extend 2 to 3 inches below the ground line for mice and 18 to 24 inches above the anticipated snow line for rabbit protection. Hardware cloth can be left on year-round, but it must be larger than the trunk to allow for growth. For small trees, plastic tree guards are also effective.
Deer feed on and damage the branches of small trees and shrubs. Plants can be sprayed or painted with the repellent; however, the most effective procedure is to hang repellants around susceptible plants. Deer can also be successfully excluded with fencing. To be effective, fences must be high (8 feet or higher) and constructed properly.
Although winter injury is a common concern in Wisconsin, appropriate plant selection, selecting the proper site, good cultural practices, and preventive maintenance will significantly reduce or prevent damage or loss of landscape plants.
Tony Seidl, ISA Certified Arborist NY-5908A
Fall Fertilization- Paying attention to the below ground parts of trees
Fall Fertilization- Paying attention to the below ground parts of trees
When it comes to taking care of trees, people tend to give the majority of their attention to the parts of the tree growing above ground, ignoring what is growing below the surface. It is often easy to spot when a tree has broken branches, large wounds, or hazardous pieces of dead wood, but the root systems of trees are most often overlooked and ignored. These systems are essential for the long term health and viability of a tree. Often times we don’t realize that a tree’s root system can be quite extensive, often containing up to 20-40% of a tree's entire biomass. Most roots are found in the top 18 inches of the soil, and 50% of those are found in the top 6. This is the area with the most nutrients, water, and oxygen, which are the essential ingredients that roots need to thrive.
Roots often face several challenges in our urban environments. Poor, disturbed, and compacted soils are common, and urban soils may be depleted of nutrients. Prolonged periods of dryness can reduce the readily available moisture, but excessive moisture and poor drainage can reduce the availability of oxygen, leading to root decay. Soil fill and too much mulch around the base of a tree can also damage roots by essentially suffocating the root system, which can lead to stem girdling roots. With all of these prospective problems it’s easy to see why urban trees don’t live as long as forest trees.
In the fall, while the parts of the tree that grow above ground start to slow down, the root systems remain active. This makes fall a very good time to perform fertilization and root system treatments, among other procedures. Our fall fertilization blend is a water-soluble micronutrient treatment that includes beneficial rhizosphere (root zone) bacteria and 3-0-20 nitrogen/phosphorus/potassium fertilizer.
Fertilization helps aid in a plant’s recovery from stress, reverses mineral deficiencies that cause chlorosis and necrosis, and improves root function without stimulating excessive top growth. This all happens while providing soluble nutrients in acidic, neutral, and alkaline soils. When more vegetative growth is desired we will mix in a higher nitrogen fertilizer as well. Fall fertilization treatments prepare plants for the cold weather, damaging wind, lack of moisture, and frozen ground.
The Certified Arborists at Hoppe Tree Service are knowledgeable of both the above ground and the below ground parts of trees. If you would like recommendations on what can be done to keep your trees thriving please contact us at 414-257-2111 or Request a quote online.
Written by: August Hoppe Certified Arborist WI-0477A
Summer Drought Stress: How to prevent long-term stress to trees
Summer drought conditions can significantly affect the lifespan of your trees if not properly maintained both during AND after the drought period. It can be difficult to remember to water trees during the summer, especially after coming out of a rainy spring season. The best, and most proactive strategy to prevent drought stress in trees is to water them regularly.
Trees need to receive 1 inch of water per week throughout the spring, summer, and fall. If the rainfall is less than that in any given week, additional watering is required to maintain adequate soil moisture. The best method for watering is a slow soak system onto the entire root zone area, either using a soaker hose or trickle from a garden hose. This approach eliminates evaporation of puddled water, which is a prominent issue due to SE Wisconsin’s dense clay soils. A slow soak also ensures the water is getting deep into the root zone. Roots can extend as far out as the drip line, or where the tree branches end, and may sometimes even extend beyond the drip line if there is enough space. The best time of day to water is either early morning or in the evening. A rain gauge is an effective method for measuring the amount of rainwater received each week.
Thanks to extensive root systems, trees are able to withstand initial drought conditions. However, prolonged drought periods can weaken trees to the point where they become targets for disease and secondary pests such as borers and disease-carrying insects. For example, non-protected American elms are more likely to succumb to Dutch Elm Disease & paper birch may have higher chance of being attacked by Bronze Birch Borers. These secondary borer infestations can occur even after the drought period has ended, while the tree is in a weakened state and still recovering.
Like all plants, turf is also affected by drought conditions and will compete with trees for water resources. If turf exists on top of the root zone, additional watering will be required to move through the turf zone and penetrate into the tree root zone. Any tree that has turf covering the root zone would benefit from removing the turf from the drip zone and replacing it with a thin layer of mulch (2-3 inches). This will reduce competition between the turf and root zone of the tree. The mulch is easily penetrable, which allows water to access the roots quicker. Mulch creates a protective layer to shield any surface roots from mower blades and ground compression. Most importantly, during the drought season mulch holds the water in the root zone, so it does not evaporate in the high heat.
The following are symptoms of drought stress to keep an eye out for: wilted leaves, smaller than normal leaves (undersized), sparse canopy, leaf scorch (browning/curling of leaf margins), yellowing of leaves, premature fall color/leaf drop. If you are concerned about your trees health contact one of our expert arborists today!
-Brittany Damschroder- Hoppe Tree Service Certified arborist, received a B.S. in Fisheries and Wildlife from Michigan State University, and has worked in the tree care industry since graduating in 2012.
Fruit and Nut Abundance-The sky is NOT falling!
In 2015 Southeastern Wisconsin experienced an exceptional amount of fruit being produced, causing an unpleasant problem for many homeowners. A walnut falling from the canopy can hit you on the head, acorns covering a sidewalk can cause you to slip and fall, mulberry and ginkgo fruit may ferment and produce a horrendous odor. It doesn’t happen every year, but when trees produce bumper crops of fruit it is easy to take notice. Why do trees make so much fruit, and when does it happen? The term used for the exceptional fruit production in a tree is mast year. Masting occurs in cycles, not every year will we see huge amounts of fruit falling from trees. As it turns out, masting is an evolutionary adaptation for successful reproduction. There are two functions trees need to pull this off; variability and synchronization.
Variability refers to the idea that not every year’s fruit production is the same. It was thought that mast years could be predicted by resource tracking. This term refers to years with an abundance of resources available such as water, light, and nutrients. The theory is that when this occurs trees will be happy and produce a high volume of fruit. However it isn’t always true, and is difficult to correlate. Instead we view masting as a cycle, due to the fact that fruit production takes a lot of energy. After a tree has a mast year it has worn out its energy reserves, and will need to recuperate and accumulate new reserves before having enough energy to mast again. If a tree produced a lot of fruit one year it is unlikely there will be a high production level the following year. The idea of cycling is a better predictor for when trees might mast next.
Fruit contains the genes necessary to produce new trees if allowed to germinate. Seeds are also food for predators such as deer, squirrels, and mice. As an important food source, fruit production cycles directly correlate with predator populations. In years with low fruit production there is less food to go around, and fewer predators will survive into the next year. In low production years all of the fruit may be eaten by predators, but it also lowers predator population for the next year. In mast years fruit production is so high that the reduced predator population can’t possibly consume all the fruit, allowing some to germinate and become new trees. This is the concept of predator satiation.
Outsmarting predators with variability doesn’t explain the whole picture, as trees also need to synchronize to be successful. Trees of the same species should all mast at the same time to increase the odds of pollination and produce viable offspring. This is another great evolutionary adaptation when cross pollination is needed. It makes sense that if pollinating with other trees is required; they all do it at the same time and in the same year. This is the idea of pollen coupling.
Trees need to know when to synchronize. So how do trees talk to one another? Our best guess is the Moran effect. This states that because of climate, not weather, similar trees can respond to similar environmental cues together. Trees that are exposed to the same climate cues and respond in sync will be able to successfully reproduce, but trees that are out of sync will be removed from the gene pool. The end result is trees that are synchronized in quantity and timing being able to maximize their reproductive potential over large land areas.
Masting is great for trees but it has other implications for the ecosystem at large. Predator population manipulation can be both good and bad. Certain bird species that rely on a particular tree fruit may disappear entirely from an area when several low yield years occur in a row. Conversely, when squirrel and mice pollutions peak with a mast year, so do tick populations that may carry human borne illnesses. Following a mast year we see an increase in Lyme’s Disease and Alpha-gal allergy (which makes us allergic to red meat). Masting increases reproduction success by working in unison, but that can also mean if you have allergies, those years can be far more difficult for outdoor enjoyment. We know if a mast year occurred this year it is unlikely to occur next year, but as of now we still don’t know how to effectively predict a mast year. Ongoing research hopes to eventually find an answer, until then stay out from under trees when they mast so you don’t think the sky is falling.