Size surprises

ISA-Certified Arborist

As a tall person, I’m a bit size-conscious, ducking to get through doorways, wondering when I’ll find another decent shoe in a sixteen – stuff like that. One thing which came as a surprise is that I can’t operate most mid-size SUVs unless I either remove my left leg, the driver’s door, or the steering wheel, all of which seem like bad options. Yet there’s plenty of legroom in a little Nissan Micra. Size does matter in some cases, but not always in the obvious direction. This is especially true when buying a tree.

For years I have passed along the nugget that smaller transplants will embarrass larger trees by overtaking them within a few years, and that unless you’re older than ninety-five, it’s best to avoid the lure of an instant forest in your landscape. Smaller trees will continue to thrive better than the big guys planted at the same time, even after they win the altitude race. However, this was based on observations and backed up by scientific modeling; there hadn’t been bullet-proof research until recently.

In June 2021 I heard a live talk on transplanting by Dr. Nina Bassuk, Director of Cornell University’s Urban Horticulture Institute, and something of a legend among arborists in the Northeast. Dr. Bassuk’s research has produced C-U Structural Soil l®, a system for constructing roads that allow tree roots to pass underneath with no damage to asphalt or roots. She also pioneered the protocol for bare-root transplanting of large trees. It’s fair to say her work has made a real impact on the world of tree care in my lifetime.

For over two decades, a cooperating tree nursery in western New York State has hosted Cornell University research. Dr. Bassuk’s transplanting study there involved comparing the health outcomes of a number of oak species in three different size classes: 4-inch, 3-inch and 1.5-inch. In arborist-speak, trunk diameter is called dbh or “diameter at breast height.” It’s a deeply non-inclusive unit of measurement, as it assumes everyone’s breast is exactly 4.5 feet off the ground. In the nursery trade, where separate jargon is required by law, stem diameter is referred to as “caliper.” This seems unduly martial, as very few trees will ever become gun stocks when they grow up.

The nitty-gritty of this project is that trees were harvested with a tree spade, a cool machine which cuts off 80 to 95 percent (depending on tree caliper) of a tree’s roots and puts the remaining root ball in a burlap-lined wire basket. This is termed “ball and burlap,” the kind of B&B that doesn’t serve breakfast. Trees were then moved over a few feet and replanted. In essence, this was the kindest and gentlest transplanting a tree could hope for: no long-distance transport, no baking in a garden-center lot, and they could hop right back into the same soil they grew up in.

Rating the trees’ progress was no beauty pageant; appearance was not a metric of success. The parameters considered in the study included hydraulic root conductance, leaf surface area, shoot elongation, percentage of dead branches, and of course mortality. Sorry that I already spoiled the ending of the story, but the data fell into a nice straight line, with the best performance by the smallest size and the worst by the biggest. This makes sense. Tree roots extend 2.5 times the branch length and 60% of roots are outside the dripline (crown projection). So when a young tree is harvested, more of its roots are captured in the root ball as compared to an older tree with a longer root system.

After five years, the difference between the size-classes was stark. In fact, none of the 4-inch caliper bur oaks (Quercus macrocarpa) survived, even with the pampered relocation service described above. To be fair, this species is known to be difficult to transplant. But only half of the 4-inch scarlet oaks (Q. coccinea) survived. Even the swamp white oak (Q. bicolor), considered the easiest oak to establish, showed significant mortality in the 4-inch class. Deadwood is another issue, and a lot of the large-caliper survivors had so many dead branches that they were disfigured.

When buying a tree, patience is a virtue that will pay off in your landscape as well as your wallet. Tree size matters – inversely.

Paul Hetzler has been an ISA Certified Arborist since 1996, and is a former Cornell Cooperative Extension Educator.


Spruce Blues and Wet-Weather Woes

ISA-Certified Arborist

When I’m asked to diagnose tree problems, folks naturally want the remedy. Sometimes the only solution is tree removal; other times it’s a cable brace, pest management, corrective pruning or fertilizing. But increasingly, the diagnosis is climate change. If anyone knows how to solve that through an arboricultural practice, please let me know.

With rising temperatures, a novel weather pattern has taken hold with longer and more intense dry and wet periods. In 2012 many areas had the lowest soil moisture ever recorded. Nonstop rain in 2013 led to flooding and farm disaster relief. A drought in 2016 set more records in some places, and catastrophic flooding hit in 2017. Drought followed in 2018, and 2019 was another massive flood year. Prolonged dry spells cause root dieback, weakening trees for several years afterward. But unusually wet seasons are just as bad for trees.

About twenty years ago I noticed a rise in the incidence of a spruce ailment called Rhizosphaera needlecast, arborist-speak for “spruce needles turn brown and fall off.” This native fungal pathogen was always considered weak and opportunistic. Historically, it only showed up when spruces (and rarely other conifers) had been planted too densely, allowing the needles to remain wet long enough for this wimpy microbe to enter foliar cells. The answer was to thin out the trees to make space between them so air could circulate, and remove spore-infested dead branches. This remedy was kind of like drinking lemon-honey tea and getting lots of rest until your cold clears up – simple, but it usually worked.

I was curious as to why Colorado “blue” spruce (Picea pungens) was much harder-hit than other species. The reason has to do with its origins: Colorado spruce is adapted to an arid environment. In fact, its foliage is actually green, and the blueish appearance is due to a heavy layer of wax (which you can rub off) that the trees make to retain moisture. So when a pathogen like Rhizosphaera that needs copious moisture for extended periods to become infectious meets a tree designed to hold moisture, an unhappy relationship ensues.

With more and more calls coming in about this issue, by 2010 I was advising people to only plant Colorado spruce on open, preferably elevated, sites. But when I began to see needlecast disease in windy, full-sun environments, it was clear a “new normal” had emerged – extended wet periods were allowing pathogens to access trees in open, ideal settings, not just those packed too tightly together.

Cornell’s Plant Pathology Lab was also dealing with higher numbers of samples, and they identified Stigmina needle blight and Cytospora canker, native pathogens that work in concert with or in place of Rhizosphaera to cause needle drop. The rate of disease advancement can potentially be slowed through a series of three fungicide applications each spring. For a mature tree, this is likely in excess of $1000 per year for the remainder of the tree’s life, an expense few can afford.

Around 2017, many Cornell Extension Educators began to advise against planting Colorado spruce, a position I heartily endorse. White spruce (Picea glauca), once deemed moderately resistant to needle disease, is now being severely affected as well. Fortunately, there’s still a contender in the ring: Norway spruce (Picea abies). Every native conifer species, whether hemlock, balsam, white pine or spruce, all face relatively new and very significant threats. As much as I prefer native species, I think it’s important to plant more Norway spruce – we need the diversity.

I recommend planting a broad range of tree species, but only those which are still appropriate for our climate. To paraphrase some good marriage advice I once got about choosing between happiness and needing to be right, “Do you want to be happy, or do you want a blue spruce?” Let’s leave them in Colorado.

For more information, see:

Paul Hetzler wanted to be a bear when he grew up, but failed the audition. Having gotten over most of his self-pity concerning that unfortunate event, he now writes about nature. Including bears, once in a while. His book “Shady Characters: Plant Vampires, Caterpillar Soup, Leprechaun Trees and Other Hilarities of the Natural World,” is available on amazon

Metal Heads and Canine Compasses

ISA-Certified Arborist

As the title of the animated American TV series Scooby-Doo, Where Are You! suggests, getting lost was a frequent premise. From 1969 to 1985, the cadre of teen gumshoes spent about half their time looking for young Shaggy, who always disappeared to smoke a joint (so it was implied), and then to satisfy his raging munchies afterward. His dog Scooby-Doo of course tagged along for the food. I recall one episode where Shaggy attempts to navigate a forest by looking for moss on the north sides of trees. He should have just asked Scooby to point North.

A 2013 paper published in Frontiers in Zoology suggests that dogs line up with Earth's North-South axis when they defecate. Researchers took two years to observe 1,893 poop events, somehow accounting for a range of weather factors, before concluding that the number one element that influenced how dogs did a Number Two was Earth’s magnetic field. Perhaps the hound-winding pre-poop turning dance most dogs perform is to calibrate their internal compass.

We all assume that many, if not most, non-human animals can find their way around without asking directions or checking their phones, but science has proven that we have innate homing abilities as well. The mechanisms are not as yet entirely understood, but one thing which may be helping humans to navigate is the fact we have metal in our heads. That’s right – move over, Magneto. Some people have more brain-iron than others, and most of us know at least one individual we suspect of having rust between their ears. The truth is that we all have ferrous-rich cells located in our cerebellums and brain stems which can help us orient to North.

Without question, other animals are much better at non-GPS navigation than humans. When we talk about critters which can expertly find their way around, the homing pigeon probably comes to mind. Homers have an uncanny ability to accurately find their way back to their owners even when taken more than a thousand miles away. True story: in New Zealand, a “Pigeongram” service ran from 1898 to 1908, complete with special stamps. Homing pigeons were also vital leading up to the Normandy invasion when radio silence was essential.

Bird navigation has been well-studied, but much is still a mystery. Although birds use a variety of mechanisms to find their way around the planet, such as landmark recognition and solar orientation, sensitivity to Earth’s magnetic field is critical. Many bird species migrate only at night, so landmarks and solar position can’t help.

Luckily for us, Earth is a kind of induced magnet thanks to its rotating core of molten iron. If it weren’t a giant magnet, we’d all be fried to a crisp by solar radiation. Recently it has come to light that animals employ a protein molecule called a cryptochrome to sense the planetary magnetic field. This involves being attuned to blue light wavelengths, those between 400 and 480 nanometers. A corollary to this fact is that cryptochromes only function during the day. So what about those night owls?

Birds, it turns out, are serious metal-heads, having (as one researcher elegantly put it) “iron-containing sensory dendrites in the inner dermal lining of the upper beak.” There you have it, clear as a bell.

Ferrous-rich nerve cells were detected first in homing pigeons, but all bird species are thought to have them. Long-distance migrants need these most, but even poultry and resident birds are known to be endowed with an inner compass. In a research paper published in the journal PLOS One in February 2012, principal author G. Falkenberg writes “Our data suggest that this complex dendritic system in the beak is a common feature of birds, and that it may form an essential sensory basis for the evolution of at least certain types of magnetic field guided behavior.”

Heavy metal is not just for the birds. Bacteria, slugs, amphibians and loads more species are unconscious collectors of iron as well. A recently published study on human responses to magnetic fields found most subjects reacted to lab-generated magnetic fields. As observed on real-time functional brain scans, subjects could even detect when the polarity was reversed as part of the study. In the March 18, 2019 issue of the journal eNeuro, lead author Connie Wang writes “We report here a strong, specific human brain response to ecologically-relevant rotations of Earth-strength magnetic fields. Ferromagnetism…provides a basis to start the behavioral exploration of human magnetoreception.”

What really caught my attention is a new study out of South Korea. In a paper published in PLOS One in April 2019, Kwon-Seok Chae et al. found that male subjects who had fasted for an entire day seemed to orient themselves in a direction they keenly correlated with food, even when blindfolded and wearing ear plugs. That I can believe.

As a last resort we can always ask “In which direction would Scooby-Doo doo?”

Paul Hetzler wanted to be a bear when he grew up, but failed the audition. Having gotten over most of his self-pity concerning that unfortunate event, he now writes about nature. Including bears, once in a while. His book “Shady Characters: Plant Vampires, Caterpillar Soup, Leprechaun Trees and Other Hilarities of the Natural World,” is available on amazon


Hoping to Be HAB-Not

ISA-Certified Arborist

Not only does it form the basis of the aquatic food web, algae have the power to put a lid on bovine burps. Algae can also be made into a substitute for fossil fuels, and is a heathy and tasty food supplement for humans. But from mid-summer through early fall, certain algae can spread toxins through freshwater lakes and rivers, posing a risk to people, pets, fish, and more. Be on the lookout in northern New York State this summer for harmful algal blooms (HABs).

The term algae itself has no strict definition. It may refer to any number of photosynthetic organisms, many of which are not even closely related. Everything from single-cell microbes to giant kelp measuring 150 feet long can be labeled as algae. Worldwide, there are more than 5,000 species of algae, and nearly all of them are beneficial.

As an example, research ongoing since 2017 at the University of California at Davis concluded that feeding a small amount of marine algae to cattle reduced their burps, a.k.a. methane emissions, by 99%. That may seem like a useless piece of trivia, but according to the UN Food and Agriculture Organization, cattle contribute more to global warming than all forms of transportation combined, because methane (CH4) is twenty-three times more potent as a greenhouse gas than carbon dioxide (CO2). Needless to say, algae may turn out to be one of our strongest allies in the fight against climate change.

For more than a decade, the US Department of Energy (DOE) has been researching single-cell algae as a fuel, calling it “one of the fuel sources of the future.” Even though it is not yet a profitable endeavor, several private companies such as Florida-based Algenol and Sapphire Energy of California are now producing algal-based fuels. A DOE website adds that “since it [algae] takes CO2 out of the atmosphere, it is a nearly carbon-neutral fuel source.” Not bad for pond scum.

Freshwater algal blooms differ from those in marine environments, such as the infamous “red tides” that bring potent neurotoxins. When folks report an algal bloom in our neck of the woods, they are talking about cyanobacteria, often called blue-green algae even though it can appear brown or reddish (never mind that most biologists do not recognize cyanobacteria as true algae). While not as dangerous as marine algal blooms, freshwater harmful algal blooms still pose a risk. The New York State Department of Environmental Conservation (NYSDEC) emphasizes that because there is no good way to tell a HAB from a benign one, people should avoid swimming in areas with visible algae, and keep pets out of such waters and off the beach as well.

The problem is that blue-green algae secrete microcystin, a toxic substance which in humans can cause rashes, vomiting, diarrhea, and in a few individuals, a life-threatening reaction. Dogs are particularly vulnerable to HAB poisoning because they may pick up objects on the beach which have come in contact with harmful algae. Symptoms of canine microcystin exposure include unsteadiness, seizures, or difficulty breathing. An exposed dog should be seen by a veterinarian immediately.

HABs can also threaten drinking-water supplies. The US Environmental Protection Agency (US EPA) states that “Toxins from harmful algal blooms are increasingly contaminating source waters, as well as the drinking-water treatment facilities that the source waters supply.” In August 2014, dangerously high levels of microcystin forced the City of Toledo to issue a “Do Not Drink” order to more than 400,000 residents, leaving them without water for three days. The Ohio Health Department advised residents not to even brush their teeth with water from the faucet. The problem was a small HAB near the city’s intake pipes in Lake Erie.

Harmful algal blooms seem to be occurring more often than they did historically. One reason is that water bodies tend to be warmer: summers are hotter than in the past, and the temperate season is longer than it used to be. A NYSDEC web page says HABs “are likely triggered by a combination of conditions that may include excess nutrients (phosphorus and nitrogen), low-water or low-flow conditions, and warm temperatures.” As you enjoy the great outdoors this summer and fall, please report any suspected harmful algal blooms to the NYS Department of Health at [email protected] or contact your local health department.

Paul J. Hetzler is a former Cornell Cooperative Extension educator.


Gypsy Moths

ISA-Certified Arborist

Like a B-grade horror film sequel, the aliens have awakened once again. Perhaps we felt a glimmer of hope at the end of the 2020 version when an entire generation of ruthless monsters died off in droves and left us in peace. But remember that closing shot of their disgusting, furry egg-mass blobs cleverly hidden out of sight? Well they’re hatching now.

If you missed last year’s gypsy moth performance, you have a better chance of catching it this season. Unfortunately. Based on egg-mass sampling, the New York State Department of Environmental Conservation predicts that areas in central and western NYS which saw moderate to severe gypsy moth outbreaks last year can expect heavy damage this year. NYSDEC’s gypsy moth page can be found here.

Native to Europe, the gypsy moth’s range now extends throughout Africa, Asia, and North America. Its genus, Lymantria, means “destroyer,” an apt designation, and its species name, dispar dispar, reflects the disparate color of males vs. females. It might as well stand for “despair, despair,” since that’s how many of us feel as we watch tree leaves vanish into the maws of gypsy moth caterpillars.

Their introduction in 1868 was especially tragic, as it was deliberate. Étienne Léopold Trouvelot, a French artist, astronomer and so-called scientist, imported gypsy moth egg masses to his Massachusetts home. He thought they could be used to make silk, despite good evidence to the contrary, and without a thought to their potential impact on New World ecosystems. Glass herbariums were safe but pricey, so he raised these fearsome defoliators the woods behind his house. What could possibly go wrong?

Today, gypsy moths are one of the most destructive forest pests in eastern North America, stripping the foliage off at least 300 species of native woody plants. They prefer oaks, but will feed on apple, pine, basswood, spruce, willow, and when population densities are high enough, almost any tree species. In an ironic twist now that EAB is here, gypsy moth caterpillars generally avoid ash. Butternut, walnut and balsam are typically off the menu, too.

Hatchling larvae are black with long hairs, or setae. As the larvae grow, they molt, shedding skins every time they advance to another phase (instar). Later-instar caterpillars develop pairs of raised blue (nearer the head) and dark red (toward the rear) spots along their backs, reaching maturity in early July. After a 14-17-day pupal phase, the adult moths emerge. The mostly-white females can’t fly from where they emerged, and just call out to the boy-moths, which are mottled brown, using pheromone come-on signals. Mated females lay on average around 500 eggs in a “blob” or mass, which they protect with buff-colored hairs taken from their underside.

These oval-shaped egg masses, tan to cream in color and about 0.75 x 1.5 inches (19 x 38 mm), can be found tucked away near whatever hiding spot the female pupated in. Very often laid on tree trunks and notably under flaps of loose bark, egg masses are usually in sheltered spots, but may be just about anywhere. Right now in early May, tiny hatchlings can be found clustered on these masses – it’s a great time to seek and destroy.

Natural predators include blue jays, robins and catbirds, but these have no measurable effect on gypsy moth numbers. The white-footed mouse, the primary reservoir of the three species of Borrelia spirochete bacteria that cause Lyme disease, has redeemed its reputation: it’s the most important vertebrate gypsy moth control, as it loves eating their egg masses. Shrews and other small mammals enjoy hearty breakfasts of gypsy moth eggs, too.

More significant agents are weather, viruses and fungi. As with the tent caterpillar species, prolonged wet, cool weather can lead to hatchling starvation, and a sudden cold snap in late fall or early winter can kill eggs before the embryos inside can winterize their cells. Cool temps also favor infection by fungal pathogens, as explained below.

An endemic soil fungus, nicknamed Entomophaga maimaiga for short, kills gypsy moth caterpillars as their populations rise. But NPV (nucleopolyhedrosis virus) is our MVP when it comes to knocking defoliator numbers down. The catch is that this naturally-occurring virus usually takes two years to precipitate a gypsy moth population crash.

In addition to egg-mass mashing, we can smother eggs that we can’t reach with a shot of dormant-oil spray. This is a very light, highly refined horticultural oil. Some people use aerosol non-stick cooking oil such as Pam, although strictly speaking this might not be legal. (I promise not to tell.)

Applications of Bacillus thuringiensis kurstaki, or Btk to its pals, will protect foliage. Found at any garden center, preparations of Btk contain a natural toxin produced by these bacteria. It is highly specific to caterpillars, and considered safe for other terrestrial and aquatic life. It must be ingested to have an effect. It does wash off, so re-apply after it rains.

Wrapping trunks with a 6” fabric strip, and then smearing it with a sticky compound made for the purpose of trapping insects (Tanglefoot and other brands) will trap larvae, which tend to commute down to the ground at night and back to the treetops in the morning. A “skirt” of burlap tied around trunks will draw caterpillars to take shelter under the fabric, and they can be squished or knocked into soapy water daily. (Caution: the hairs can cause skin rashes and sometimes upper-respiratory irritation.)

Also, don’t move firewood! Unless it’s from the woodpile to the house – that’s OK.

Healthy deciduous trees can re-foliate after being stripped of leaves, but at great cost to their energy budgets. Pines and spruces, on the other hand, are not endowed with re-foliation powers. They’re left with only a smattering of green razor stubble with which to photosynthesize; thus gypsy moths can cause such conifer species grave harm. When defoliation occurs in successive years, tree mortality becomes a concern.

Don’t be shy about scouring the back yard in the coming days for egg masses to squish, and it’s probably a good idea to stock up on Btk before the June rush when everyone begins to notice the caterpillars. Let’s hope there’s no remake next year. For more information, see NYSIPM’s gypsy moth resource page.

Paul Hetzler is an ISA-Certified Arborist and a former Canton Cornell Cooperative Extension educator.

Do Nothing about Invasive Plants


Until recently, ignoring problems in hopes they’ll go away hasn’t served me well. However, a decade-long study done by Cornell University researchers has clearly shown that avoidance is the best way to manage garlic mustard (Allaria petiolata), a pernicious exotic plant. Evidently I’ve been doing a great job in the fight against this aggressive and troublesome invader.

Native to most of Europe and parts of western Asia and northwestern Africa, garlic mustard is in the cabbage and broccoli family (Brassicaceae), and indeed was imported to North America as a culinary herb in the early 1800s. It’s not entirely evil, as it has the spicy tang of mustard with a hint of garlic, and can be used as a base for pesto and sauces, and to flavor salads, soups and other dishes. Unfortunately, eating it has not worked well as a control strategy.

Garlic mustard is a biennial that begins as an inconspicuous first-year plant (rosette). At a glance, its rosettes look similar to wild violets, having triangular, somewhat heart-shaped leaves that have coarsely toothed margins and wrinkled leaf surfaces. In the second year it sends up a tall flower spike, the four-petal white flowers developing into slender pods (siliques) bursting with tiny round seeds. This is one of garlic mustard’s unpleasant features, as it loads the soil with seeds that remain viable for ten or more years.

Like all invasive plants, garlic mustard is not browsed by herbivores (if you don’t count vegetarian humans), and has no effective insect pests or diseases to keep it in check. As mentioned, it gets high marks for reproduction, and can form thick monocultures in forest environments. Its roots exude compounds that alter the soil chemistry to favor its survival at the expense of other species. Known as allelopathy, this mechanism also harms mycorrhizae, symbiotic root fungi which contribute greatly to tree health. When dense armies of these plants compete for water, nutrients and sunlight, natural forest regeneration is curtailed and native ground cover is stressed.

Sounds like we should gather a posse and rise up against this intruder; pitchforks, torches, and pikes at the ready. Well, yes and no. If garlic mustard has just appeared at a location in the past one or two years and their numbers are low, yes – yanking them out by the roots is the thing to do.

But according to Dr. Berndt Blossey, a Cornell University conservation biologist who specializes in invasive plants, pulling up large swaths of garlic mustard is not only futile, it is worse than leaving it alone. It bears echoing: When well-intentioned people rip out this stuff, it actually prolongs the infestation period because the plant self-limits (more on that below) if undisturbed. Also, these mass garlic mustard-ectomy events do more damage to the ecosystem than the target species itself does.

There are cases where research seems pointless because cause and effect are so obvious: maple sap flows up from the roots during the day; goldenrod causes allergy symptoms; and garlic mustard wipes out native wildflowers and adversely affects salamanders. These assumptions make sense, given the “evidence,” but upon close examination, all of the above statements are false.

Dr. Blossey has long contended that deer abundance and non-native earthworms are the drivers of garlic mustard infestation. Garlic mustard only establishes after earthworms have invaded a site for some years, he says, and although how deer spread earthworms is not yet known, they apparently do, as exclusion plots show. I first heard Berndt’s idea that well-established garlic mustard should be left alone in 2014 at a talk he gave at Cornell. I was surprised, and admittedly rather skeptical. But he and his team have now done enough controlled trials and amassed enough evidence to back up his assertions.

It turns out that while garlic mustard competes with native species, it does not displace them where deer are excluded or drastically reduced in number. And it is earthworms, not our maligned invasive plant, which make a neighborhood less attractive to salamanders. Furthermore, garlic mustard dwindles in biomass, plant vigor, and site prevalence over time. Within ten to 12 years it becomes scarce as a species, the remaining plants greatly stunted.

Side-by-side controlled trials showed that where garlic mustard is “managed,” the plants are considerably larger, and cover a much higher percentage of a site (at times by an order of magnitude) than the sections where nothing has been done. Not only that, but biomass on the managed sites tended to be roughly stable over the ten-year time frame studied, whereas it declined year after year in the unmanaged plots.

Pulling garlic mustard where it is abundant prolongs its run. It also robs a great deal of nitrogen, macro- and micronutrients, and organic matter from the ecosystem. Mass-removal also results in the site being trampled, and runs the risk that soil and native plants might be inadvertently removed.

A much better use of our time and energy, Dr. Blossey advises, is to scout sites that aren’t known to have garlic mustard yet, and also to kill as many deer as possible. Especially the latter.

An interesting side note is that if deer were managed to 5-7 per square mile, not only would it drastically reduce the rate of garlic mustard spread, Lyme disease would cease to be a human-health threat (this from Dr. Paul Curtis, the NY State Extension Wildlife Specialist at Cornell University). I say amen to that!

Professor Blossey’s February 26, 2021 talk “When Doing Nothing is the Best Invasive Plant Management Tool” can be found at

A former Cornell Cooperative Extension Educator, Paul Hetzler is often in a recliner, helping to fight garlic mustard.


Science is lunacy

ISA-Certified Arborist

As if today’s war on science wasn’t bad enough, it seems researchers have been courting further bad press by admitting they’ve spent countless hours on lunacy studies. To clarify, this research is on lunar effects on our behavior and sleep – I don’t know of any work being done to analyze sheer foolishness and irrational acts, the other kind of lunacy. Given the events that dominated the news this January, though, maybe that would be a fair line of inquiry.

The idea that phases of the moon impact human behavior goes back a long way; indeed the term lunacy was coined in the 16th century to describe this very effect. In modern times there are myriad anecdotes from law enforcement, emergency room workers, and others that more crimes, injuries and/ or psychiatric hospital admissions occur around the full moon as compared to other times of the month. It is a sad fact that lunacy was once (and occasionally is yet today) used in the pejorative to disparage episodes of mania or psychoses wrought by severe mental illness. There is now strong evidence that the moon really does affect how such disorders manifest, and it also makes a difference to all of us in terms of sleep.

Although older scientific reviews of lunar influences on our lives led to mixed conclusions, that has changed. In January 27, 2021, scientists from the National University of Quilmes in Argentina, the University of Washington, and Yale released a paper showing that their experiment, the largest, most in-depth study on lunar cycles and sleep ever done, proves the moon has a very significant effect on sleep. Until now, all investigations done on the subject had relied on self-reporting of sleep experience, a major weakness.

Conversely, this collaborative study used wrist monitors to record brain activity and other factors to evaluate sleep patterns of 98 people across several 29.5-day lunar cycles in three Argentine villages. One town was on a modern electric grid, while a more rural hamlet had a crude electrical system, each house with perhaps one or two lights. A third, very remote settlement had no electricity at all. In every case, participants had notably altered sleep, based on the phase of the moon.

Lead scientist Dr. Horacio de la Iglesia said the research team saw “…a clear lunar modulation of sleep, with sleep decreasing and a later sleep onset in the days preceding a full moon. …although the effect is more robust in communities without access to electricity, it is present in communities with electricity.” On average, participants went to bed 30 minutes later in the three days prior to a full moon. More remarkable yet is that even in well-lighted homes, subjects lost an average of 45 minutes of sleep per night during this time. In the village with no electricity, participants slept a whole hour less on each of the pre-full moon nights.

The team feels that the changes they recorded might be an ancient adaptation for making use of additional natural light during each full moon. Regardless, they say that this phenomenon must be taken into account in all sleep studies going forward, a very important point.

But moonlight is not the only factor that varies with each lunar cycle – there’s that whole gravity thing that sloshes our oceans around. Lunar pull varies on a roughly two-week pattern. The strongest pull is the 14.8-day “spring-neap cycle” caused by the joint gravitational force of the Moon and Sun when they’re aligned, and a lesser 13.7-day “declination cycle” that depends on how close the Moon comes to Earth’s equator each month. Being that we are “…giant bags of mostly water,” as humans were once described on Star Trek, it seems foolish to contend that the moon does not tug at us in some way. The question, though, has always been in what fashion and to what extent we are influenced.

An April, 2018 article in the journal Molecular Psychiatry sheds light on the connection between certain mental illnesses and the moon’s position. Dr. Thomas A. Wehr, a scientist at the National Institutes for Mental Health’s Intramural Research Program in Bethesda, Maryland, conducted a two-year study on potential lunar effects on bipolar illness involving seventeen patients with the disease.

Dr. Wehr found a distinct pattern of body-temperature and sleep-cycle changes in these patients, as well as a tendency for them to rapidly switch between the manic and depressive stages of bipolar illness, that coincided exactly with lunar phases. He even verified significant changes in the duration of his patients’ mood cycles that precisely corresponded to the so-called “supermoon.” This is when a full moon happens within 24 hours of perigee, the time that the moon comes closest to us in its monthly orbit around Earth.

The patients in Dr. Wehr’s study did not always flip to depression or mania during each and every declination (13.7-day) or spring-neap (14.8-day) lunar cycle, but when the subjects went through a mood switch, it tended to happen in one of these lunar-tide phases. Although he does not claim the moon caused mood oscillations, Dr. Wehr did say the data suggest a “…possible biological mechanism through which lunar gravimetric cycles might control mood cycles.”

Another thing is that the movement of salt water across the face of our planet creates small but measurable electric currents. We don’t understand as much about all the ways we might react to electrical changes due to the moon’s position, but we do have some information.

In a report by Linda Geddes of the BBC, published on July 31, 2019, Dr. Joachim Fisahn with the Max Planck Institute of Plant Physiology in Potsdam, Germany admits that the electrical field changes induced by tidal flows are “incredibly small.” Nonetheless, he points to experiments proving that these tidal-based current variations affect plant root growth, asserting this is supported by “over 200 publications.”

Admittedly, we’re not plants, though we can sometimes feel rooted to our seats during this Covid-19 era. But electrical fields are known to alter human brain function. In a March 18, 2019 article in The Journal of Neuroscience, a research team from the University of Tokyo and the California Institute of Technology revealed that even minute electrical fields can reduce human alpha-wave brain activity. Alpha waves are those associated with a relaxed or meditative state.

Knowing that we all lose sleep as the full moon approaches, we should try to avoid lunacy by exercising a lot more patience in the way we conduct our relationships, motor vehicles, and other things that have a high hazard potential should something go awry.

A longtime North Country resident, Paul Hetzler is an arborist, naturalist and author. He now divides his time between Canton NY and Val-des-Monts Québec. His book Shady Characters: Plant Vampires, Caterpillar Soup, Leprechaun Trees and Other Hilarities of the Natural World, is available on amazon.