Earlier this year I attended a talk on plant disease diagnostics as part of my continuing education as an ISA Certified Arborist. The talk was given by a highly respected individual whom I have had the pleasure of learning from since my early days as an arborist in central Ohio. This time, one of the first statements spoken caught my attention immediately. I paraphrase it into something like this:
Bend So You Don’t Break
Last summer, I had the opportunity to introduce our field staff to the practice of yoga. In heavy work boots and on a hard concrete floor, we made our way through Triangle Pose, Downward Facing Dog, and even a few Sun Salutations. Practicing yoga for 20 years and teaching it for the last 10, I’ve learned that the stretches and postures of yoga can help keep the joints and soft tissues of our body, like muscles and tendons, healthy and functional.
Growing Degree Days
This semester I am enrolled in a class called Integrated Pest Management, taught by Dr. Luis Cañas at The Ohio State University. One of the first lectures we had was centered around the effects that the environment has on insect populations. As we explored this theme we soon came across the concept of “growing degree days”, and I was reminded of how useful this idea is to increase awareness of what is happening in the natural world around us and to be aware of when potentially damaging insect pests are about to emerge.
Identifying & Managing Rhizosphaera Needle Cast
Humid Air: Tough for Plants and People
Soil Compaction = Not Good for Trees
Soil compaction is a big no-no for trees. When soil is compacted (above left graphic), water and oxygen cannot get to the vital root system of the tree. Water will collect on the surface and evaporate since it is unable to penetrate the soil. Seeing as trees need water and oxygen to live, compacted soil can quickly and severely impact the health of a tree.
New Research: Boxwood Blight Update
If you read my first installment on this relatively new disease, you will know the major difficulty of this pathogen (Calonectria pseudonaviculata) is that it infects otherwise healthy plants, and once it is at a site, removal and destruction of the infected plants is recommended, with no plant replacement for 3-5 years. This is because the spores remain in and on the soil to infect new plants. Existing asymptomatic plants were to be sprayed with fungicides to help prevent infection.
That "Stuff" Growing on Bark
As Central Ohio moves further into winter, and the majority of deciduous trees have dropped their leaves, bark becomes increasingly visible. Bark is an interesting and important characteristic for trees and tree identification. It doesn’t take long for a novice naturalist to distinguish certain tree species based almost entirely on the bark of a specimen (Beech, Hackberry, River Birch, etc.). Upon further inspection of a tree’s bark an observer might notice organisms growing on the trees bark. A large variety of fungi can be seen on the bark of deadwood in trees and is usually associated with poor health of that particular branch or the entire tree. However, fungi are not the only organism to inhabit the bark of trees.
A Boxwood Bummer
I wanted to dedicate this installment to Boxwood Blight, since this is a disease which has the potential to disrupt formal landscapes all across the state. The disease is fungal, and affects boxwood, especially the cultivated varieties ‘American’ and ‘Suffruticosa’. It is relatively recent in the United States, and was found in Ohio nurseries in 2011.
Don’t get Fooled by the Fall Color of Conifers
Every fall I get calls from folks concerned about yellow needles on their evergreen trees. Often times I’m told that the trees are sick or that they appear to be dying from the inside out. There are some disease and insect problems that can cause yellowing and premature loss of needles in conifers but most often what people are reporting is just normal fall color.
Test Before Treatment: Soil & Tissue Testing
I find it interesting that test procedures recommended in the medical field for human health have become part of the expected methodology, but not so much in arboriculture, for tree health. As arborists, we are trained that a soil test should be done prior to recommending fertilization, for example, but I don’t know of many outfits that make soil sampling a part of their modus operandi.
Fear no Weevil (With Fall Systemic Insecticide)
As we prepare for another season of Fall Tree Wellness, another important insect pest to take note of is the White Pine Weevil. White Pine Weevil is a damaging pest to a broad range of conifers, including White, Scotch, Red and Austrian pine as well as Colorado blue, Norway, and Serbian spruce. Douglas-fir can also be attacked.
The Late Season Blues (or Yellows or Browns)
Magnolia Scale: Take a Look!
Fall Webworm In Full Effect
Verticillium Wilt
It’s hard to miss this disease once we enter the hot dry months of summer. Without fail, each July/August I start to see trees turning brown and wilting suddenly, usually in patches within the canopy that can be traced back to entire individual limbs that have died. More dramatically, an entire tree…
The Importance of Green Leaves
I have been noticing what I consider to be an unacceptable amount of chlorosis in urban trees around Columbus. In general, chlorosis is the yellowing of plant foliage caused by a lack of chlorophyll. This is a problem because plants depend on chlorophyll to absorb energy from sunlight and to survive. Several…
Black Knot Disease In Plum & Cherry Trees
Witch-Hazel Cone Gall
I find insects that cause galls to be really interesting. There are many different types, usually host-specific, with various shapes and sizes of galls formed. In most instances, the feeding of the insect causes an abnormal growth reaction in the plant that forms this gall where either the adult or the immature insect lives inside.
Fire Blight is No Delight
This year has been a particularly bad one for fire blight on Pear and Apple trees. Fire blight is a bacterial disease that affects plants in the Rosaceae family, causing a characteristic blackened wilting of leaves and twigs. This family of plants is also popular for its landscape value, both for flowers and fruit production. Pear, Cherry, Rose, Apple, Serviceberry, Cotoneaster, Hawthorn are just a few trees and shrubs that are very familiar to us. Have you noticed a profusion of dead, blackened leaves in your neighborhood? In your trees?