Everyone loves big, veteran trees. They have a certain distinction and royalty in our forests and landscapes. The first question asked is, “I wonder how old that tree is?” Determination of the actual age of a standing, tree is difficult. There are many methods and techniques. Some are fairly accurate and many are just good guesses.
Q) I have a maple tree (it is either an ‘October Glory’ or ‘Autumn Blaze’) that has what I assume to be a rather large sucker at the bottom. The diameter of the sucker is about 2″ and the tree trunk itself is 7″ in diameter. I have attached pictures of it from different angles. I would like to know if it is ok to remove it? I’ve read quite a bit about these and that late winter/early spring is a good time to remove them. – J.M., Crown Point, IN A) Some landscape plants produce vigorous, upright stems that become troublesome as they out compete better-formed branches and shade out the rest of the plant. These remarkably fast-growing, upright stems are called “suckers” if they come from the root system. You are correct that late winter/early spring before the new growth begins is the best time to try and[Read More…]
Purdue’s Plant and Pest Diagnostic Lab (PPDL) receives more than 2000 samples for diagnosis each year. We’ll highlight some of the more interesting cases in the Purdue Landscape Report in brief case studies like this. PPDL Case Study #1: White Fungi on Crabapple Branch Earlier this year a landscaper submitted several photos of a crabapple he had been treating for apple scab and borers. He noticed white, fan-shaped fungi growing on the bark of a still-living branch (Fig. 1). At first glance this is surprising because most fungal fruiting bodies arise from dead wood. After obtaining additional photos showing the fungus close up (Fig. 2) we could identify it as Schizophyllum commune, which is reported to occur on hundreds of species of trees and is one of the most common fungi found on wood. S. commune is a sap rot (a.k.a. canker-rot) fungus; a wound invader that spreads from an[Read More…]
It’s that time of the year. Starting in the southern portions of the state and gradually moving north, trees, shrubs, and flowers are beginning to break bud, showing the flowers that have been protected all winter long. One of the first trees that you will notice, increasingly out of place more each year, is callery pear. You probably know callery pear by their cultivar names, such as ‘Bradford’, ‘Cleveland Select’, ‘Aristocrat’, etc. Bradford pear was a staple specimen in landscapes for decades. For many years the trees never produced fruit, but once other cultivars were introduced to the landscape, cross-pollination allowed fertilization to occur and fruit was thus produced. We will further examine the biology and history of how this occurred in a future article. The current status and outlook of callery pear is not positive. This species has become highly invasive in many areas around the Midwest, escaping into[Read More…]
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…]
Colorado blue spruce is not native to Indiana (no spruce is!), and it often suffers from environmental stresses such as drought, excessive heat, humidity, and compacted or heavy clay soils—making it an already poor choice for our landscape. If that weren’t enough, it also suffers from needle cast diseases. Needle cast is a generic term that refers to foliar diseases of coniferous plants that result in the defoliation (“casting off”) of needles. Needle casts vary by host, and severity is dependent upon the age of infected needles. Of all the foliar diseases affecting woody landscape plants and shrubs, needle casts are the most serious for the simple reason that coniferous plants do not have the ability to refoliate, or produce a second flush of needles from defoliated stems. Rhizosphaera needle cast is a fungal disease, caused by Rhizosphaera kalkhoffii that attacks the needles of Colorado blue spruce in the spring,[Read More…]
Fill in the blank: Apply crabgrass preemergence herbicide when____________is in bloom. If you said forsythia, you would be correct. Most of us have been told the answer to this for many years, but have you ever thought to yourself, ‘Is it true?’ There are many ways that people make decisions on when to apply herbicides. Some of you may use growing degree-days, phenological cues (Figs. 1 and 2), or are you the one that says, ‘I always put down my preemergence (PRE) herbicides on March 15th’? If you are the latter, there is a good chance that you spray a great deal of postemergence (POST) herbicides because of the weeds you missed with the PRE application. So, what exactly are phenological cues? Phenology is defined as the study of cyclic and seasonal natural phenomena, especially in relation to climate and plant and animal life. The use of phenology is applicable[Read More…]
Finding a qualified tree service is important protection for the tree owner. Often, less credible tree companies follow storms for a “quick buck” and move out of town as fast as the storm. Knowing how to hire a reputable arborist can help prevent becoming a victim all over again. A professionally trained arborist can help determine if a tree can be saved. Even if the tree must be removed, safety and training are still needed to prevent additional damage from the removal. In a time of disaster, a fast recovery is desirable, but not taking the time to hire a reputable tree service may create greater problems in the future. When hiring a tree care service: Certification – Ask if the arborists on staff hold an ISA certification. ISA offers a range of certification credentials from Certified Tree Worker/Climber Specialist to Board Certified Master Arborist. To be certified, individuals must[Read More…]