Lecanium Scale (Part Two)
Recently one of my clients in Dublin ended up with three crabapple trees that had a heavy infestation of lecanium scale. We tried some treatments but the trees had declined and the client made the wise decision to remove and replace them.
Best Practices for Watering Your Trees
Last Fall I planted a Nikko maple (Acer maximowiczianum) for one of my neighbors. Somewhat uncommon, Nikko maple is a small statured, 20 - 30’ at maturity, trifoliate, hardy tree with nice fall color. It has good urban tolerance and was a good fit for its location with overhead utilities. I have been watering this tree somewhat regularly with a large watering can that I can easily carry across the street and have been pleased with the healthy appearance and good amount of new growth that has emerged this year. As far as I could tell the tree looked great so you can imagine my surprise when I came home recently from a long weekend getaway and discovered that the top half of the tree’s canopy had turned brown.
Worms by the Bagful
Worms by the bagful. Bagworms, that is. This interesting insect is not really what we would usually call a worm, but is considered a caterpillar instead. While most caterpillars pupate into a flying adult (moth or butterfly), the female of this species never emerges from her mobile home. The male does, and he flies to the female so they can engage in activities that ensure the species does not die out.
A Word of Caution
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:
When and How to Prune Lilacs
Common lilacs (Syringa vulgaris) are a favorite landscape shrub here in Ohio and beyond, with flowers that provide beauty and an unmistakable fragrance every spring. Other cultivars of lilacs offer different habits and uses in the landscape, but provide the same display of flowers that we all love. In order to ensure you get the most flowers on your lilac year after year, it’s important to know when and how to prune them.
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
Rhizosphaera needle cast (RNC) – quite a mouthful, especially when one is an arborist in training, still green in the green industry. My supervisor had just handed me a photocopy of a fact sheet on the disease since I had asked him about spruce trees I had been seeing with defoliating branches.
Humid Air: Tough for Plants and People
Summer in central Ohio brings good times outside but also often brings hot humid air. Heat and humidity can aggravate some foliar fungal disease on trees and shrubs. One of the most common diseases we see is rhizosphaera needle cast on Blue Spruce trees.
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)
Springtime is long gone, even though it only seems like a couple of months ago that we were coming out of winter. Suddenly, here we are, getting ready to enter the fall season, and true to form, during the past several weeks I have been seeing trees go into what we call “late season blues”.
Magnolia Scale: Take a Look!
“Take a look”, I said to my concerned client, as we stood in the shade of her Magnolia tree. I had just handed her my hand lens, and I showed her how to get it close to her eye as she peered through it. I wanted her to see what was in my hand – a dead adult Magnolia scale insect.
Fall Webworm In Full Effect
We’ve received a high volume of calls over the last couple of weeks about “bagworms” in client’s trees. In central Ohio, true bagworm feeds predominantly on evergreens - arborvitae, spruce, and junipers although some deciduous trees can be hosts as well. Generally, this
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…