Like many powdery mildew diseases, high relative humidity but not high rainfall is a key to dogwood powdery mildew, caused by the fungus Erysiphe pulchra. There is a good bit of this disease this year in northeast Ohio, which is quite dry, and yesterday I took a look at some flowering dogwoods (Cornus florida) growing in pots in trials. There was a good bit of fungal mycelial growth and spores en masse evident on the foliage (what is called the “sign” of the pathogen), which is something everyone is familiar with for many powdery mildew diseases. Good examples are lilac...

  The 4th Question of Plant Problem Diagnostics (http://www.oardc.ohio-state.edu/floriculture/images/20_Questions_on_Plant_Diagnosis.pdf) is “What Do You See?” in terms of symptoms of plant damage. The 6th Question (after “What is the Overall Health?) is a return to the idea of symptoms with “What Exactly Do You See?” I was reminded of this the other day when looking at an Amur maackia tree in my backyard. The tree foliage is mostly above arms-length, but I could see that Japanese beetle flyers had no problem, munching with their chewing mouthparts, leaving sections of leaves partly...

I posted a BYGL Alert on July 20 regarding Cicada Killer Wasps (Sphecius speciosus) cruising lawns and landscapes in southwest Ohio.  However, since that time, I've been slammed with reports and questions concerning these "giant wasps."  So, I'm reissuing my cicada killer report; it appears there are some very heavy localized populations.

These large wasps are the nemesis of Dog-Day Cicadas (Tibicen spp.), so it is no coincidence that they appear on the scene when dog-day cicadas emerge.  Cicada killers are the largest wasps found in Ohio, measuring 1 1/...

I came across early instar milkweed tussock moth caterpillars (Euchaetes egle) feeding on their namesake host yesterday and they reminded me of an e-mail message I received last year.  The message was from a well-meaning monarch butterfly (Danaus plexippus) enthusiast who asked how they could control tussock caterpillars so they wouldn't compete with monarchs.  I was aghast.  We celebrate the rejection of a monarchy each July 4! 

It can't be denied that milkweed tussock moth...

Last week, as I was walking into the office one morning, I suddenly noticed what appeared to be a strange swelling coming up out of the center of one of the succulents, commonly called “hen and chicks” (Sempervivium spp.)  I decided to keep an eye on it as I passed daily since the plants were clustered at the sidewalk by the entrance. 

After a couple of days, it began to appear to me that it was going to be a stalk of some kind.  In rapt amazement, I watched as I saw flower buds form on that stalk, which was about 6” tall.  In all of my plant gawking years, I have never...

Traveling through southwest Ohio this weekend, I noticed ever-expanding patches of birdsfoot trefoil (Lotus corniculatus) along roadways, in landscapes, and in home and commercial lawns.  Yet another story of dueling plant cultivation interests.  This perennial, spreading, herbaceous legume is native to Europe and Asia.  It was introduced into North America for use as a forage crop harvested for hay or used in pastures.  Plants can survive and thrive in a wide range of soil and environmental conditions that would limit the use of other forage crops such as alfalfa.  Indeed, you...

While taking photos today of willow pinecone galls for a BYGL Alert, I was constantly strafed by a maniacal horse fly (Tananus spp.).  These hefty flies belong to the family Tabanidae which is the largest family of bloodsucking insects with over 4,500 horsefly species known worldwide.  There are several species in Ohio ranging in size from 3/8 - 1 1/8" in length.  The crazed fly buzzing me was T. abdominalis.  It doesn't have a common name other than #@%%# fly!  At least, that's what I called it.

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Arguably, one of the weirdest galls found in Ohio is produced on willow by the gall-midge, Rhabdophaga strobiloides (family Cecidomyiidae).  The gall's appearance isn't weird; it looks like a pine cone.  However, finding a "pine cone" on a willow is weird.  As the common name implies, the Willow Pinecone Gall, which is sometimes called the "pine cone willow gall," closely resembles a pine cone with closed seed scales.

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  This spring I wrote of sour gum/black gum/tupelo/pepperidge (Nyssa sylvatica) when I noticed for the first time that I had a male tree (with stamens) and a female tree (with pistils) in my back field. Until then I thought of them as just two tupelos. Well, the bird-beloved result of their union have now resulted in greenish fruits which soon will be blue-purple. So, flowers, fruits, now a word about  – foliage. Tupelo leaves are wonderfully lustrous green in spring and summer before turning intense scarlets, oranges, and purples in fall. But, wait, the time has come, as every...

  Hydrangea is a genus of great range and beauty. Panicle types such as PeeGee hydrangea. Mopheads. Climbing hydrangeas. Oakleaf hydrangeas of beautiful panicle flowers and wonderful fall foliage. Delicate pinks and blues, sometimes on the same plant. Electric colors to make a big splash. Hydrangeas were on display, revealing a high level of horticultural expertise at AmericanHort’s Cultivate’16 this past week as well as in the horticulturally laissez-faire world of the ChatScape, where my daughter Sara took a picture of the creams and pinks of an oakleaf hydrangea panicle today...