The time is now to start protecting your trees! Now that your ears are perked up, let’s talk a bit about Southwest injury on trees. Bark cracking (Fig.1) is a phenomenon that occurs in many species of trees and can have many causes. One of the most common types of bark cracking is termed Southwest injury. Southwest injury occurs during the winter months on the lower section of the trunk on the southwest side. This happens when there is a sudden temperature drop, for example, the sun going behind a cloud during the winter. The freeze-thaw cycle happens very quickly when there is a change from very warm to cold conditions, which results in a crack. If there is a snow pack, the reflection of sunlight on the bark will actually increase the temperature in the bark (Fig.2). Usually Southwest injury occurs on thin-barked trees, such as Acer spp., Cercis spp., Malus spp.,[Read More…]
Common Abiotic Problems of Ornamentals: Soil pH Effects on Fertility
An abiotic stress in plants is a stress due to a non-living factor, such as temperature, moisture, herbicides, etc. Biotic stress includes a living organism, such as a fungi, insect, etc. This series will explore some of the most common types of abiotic stress you may find in landscapes and nurseries. What is wrong with this maple? How would you correct the problem? If you guessed manganese deficiency, you would be correct. In areas with high pH, such as many locations in the Midwest, manganese (Mn) deficiency in maple is very common. When the pH of the soil is above 7, manganese is not readily available to the plant, even if there are sufficient amounts of manganese in the soil. As the pH of the soil increases, manganese is less and less available. We tend to begin seeing manganese deficiency when the pH is above 6.3 (Fig. 1). [Read More…]
Common Abiotic Problems of Ornamentals: Transplant Shock
An abiotic stress in plants is a stress due to a non-living factor, such as temperature, moisture, herbicides, etc. Biotic stress includes a living organism, such as a fungi, insect, etc. This series will explore some of the most common types of abiotic stress you may find in landscapes and nurseries. We’ve all experienced the problem. Sometimes it’s barely noticeable, and other times it results in death. Even if you don’t notice, it most likely still occurred. Environmental conditions can be helpful, or quite the opposite. Of course, we are speaking of transplant shock. Transplant shock occurs when plants become stressed due to poor root establishment, often mimicking drought stress. The severity of transplant shock is dependent on many factors, which include plant species, soil type/quality, moisture, temperature, growth stage of the plant, root loss from the nursery, as well as many other factors. If transpiration rate (loss of water[Read More…]
Cultural Plus Chemical=A good weed control combo in landscape beds
This article, and many others, will be presented at the 2018 Purdue Turf and Landscape Field Day on July 10th. Registration is open and available online: https://www.mrtf.org/event/turf-and-landscape-field-day/?event_date=2018-07-10 Here is the lineup for the field day. A cultural weed control method is one that involves steps to reduce or eliminate weeds via maintenance techniques. In landscapes, the most common type of cultural control is mulching. Mulching provides many benefits in the landscape, including moisture retention, temperature consistency of the root zone, improvement of soil structure, addition of organic matter, aesthetics, and, perhaps most important, a significant reduction in weeds. Mulch prevents weeds a couple of different ways. Many weed species require sunlight for germination to occur. By shading the soil beneath the mulch, weed seeds that require sunlight will not begin to germinate. The other way that mulch prevents weeds from germinating is by providing large air spaces (macropores) between the pieces[Read More…]
Top Arborvitae Aggravations
Arborvitae varieties (Thuja spp.) provide some of our most beautiful and versatile evergreens for landscapes, with an extensive selection of sizes and types. Unless they get proper care, they also give us some frustrating failures. Here is my list of the most frequently encountered ‘Arborvitae Aggravations’, based on the samples and questions we get in the PPDL; in no particular order. Transplant stress: Transplant stress is a normal result of planting or moving any tree or large shrub but it is frequently more serious for conifers like arborvitae. If the plant has dried out at any point before transplant the stress and browning of foliage will be much worse. Don’t keep root systems soggy wet but do make sure they stay evenly moist until planting. During the first summer be especially vigilant about watering. Keep soil evenly moist and make sure water penetrates into the full root zone. After establishment[Read More…]
Did mulch cause apartment fire?
On May 2nd an apartment fire in Greenwood occurred that reportedly originated in the mulched landscape beds. Unfortunately 56 renters were displaced that day, but fortunately no injuries were reported. Several Indianapolis news organizations reported on the origins of the fire that included a couple of quotes that were not entirely accurate. One of those interviewed stated that the most likely cause of the mulch catching fire was due to a cigarette being discarded, which happens quite often during dry periods and is correct. The quote that stood out was, ‘The mulch itself can decompress over time, decompose, and that decomposition can cause a chemical reaction that can actually cause the mulch to catch on fire by itself.’ This statement, taken at face value, can make sense to some folks. Think about wet hay catching on fire in a barn, or the mulch fire that occurred in Southern Indiana[Read More…]
Purdue Landscape Report En Espanol: Lo barato sale caro: Profundidad de siembra adecuada = éxito a largo plazo
Translated by: Dania Rivera, Ornamental Horticulture Extension Specialist, University of Puerto Rico “El mejor momento para sembrar un árbol es veinte años atrás. El segundo mejor momento es ahora” Anónimo Si vas a hacer algo, hazlo correctamente la primera vez. Esto es cierto para muchos aspectos de la vida, pero, cuando se refiere a la siembra de plantas, esto suena especialmente cierto. ¿Cuánto tú crees que es la expectativa de vida promedio de un árbol en una localización urbana: 40, 50, 60 años? ¿Qué tal diez años? La expectativa de vida promedio de un árbol urbano se estima desde siete (Moll, 1989) hasta no más de 20 años (Roman y Scatena, 2011). Lo que complica el problema es que un árbol maximiza sus beneficios ambientales solo después de los 30 años (USDA-FS). Cuando nos gusta hablar de todos los beneficios ambientales que un árbol agrega a una comunidad, uno debe[Read More…]
Winter Injury Could Cause a Reduction of Flowering on Perennial Trees and Shrubs
Winter of 2017-18 was pretty harsh compared to most years. Much of central and northern Indiana experienced 13 or more days well below 0º F, while southern Indiana had 4- 5 days just a few degrees below 0º F. In addition, gusty winds contributed to further injury by desiccation of buds and twigs. The consequences still remain to be seen. While some spring flowering trees and shrubs may perform admirably this season, some species will have few or no blooms at all, particularly in the northern half of the state. In addition, some plants may be late to leaf out leaving us concerned that they died overwinter. Some shrubs such as forsythia may flower only on the lower branches, where snow cover and leaf litter provided good insulation (Fig. 1). But for many specimens, there may be no flowers at all. A recent check of buds on forsythia plants on the[Read More…]
