Date Published: May 24, 2018
Authored by: Jim Chatfield

Whaaat. That first picture got your attention, did it not. Pawpaw flowers are not white!  But they are beautiful, and now past. To further digress, Michael Dirr wonderfully terms pawpaw flowers “lurid purple” in color, and purple is a color made up of red and blue, and after all, white light is made up of red, green, and blue, so a perfect lead-in to…

…This past weekend, when I took a walk through my yard, starting with a side area where there is a patch of lily-of-the-valley (Convallaria majalis). I took a sniff of the perfumey flowers (smell but do not eat – all parts are poisonous), then noticed that the patch was not as large as I suspected. In fact, at least half of the patch was wild lily-if-the valley (Maianthemum canadense).

I have seen this in woodlands often, but have ignored it probably for years in my yard, supposing it was Convallaria.  And spreading among these as well was sweet woodruff (Galium odoratum, the May wine herb), intruding on this scene. Three white flowers taking up the ground amidst lilac, striped maple, weeping katsura, kousa dogwood, and other ornamentals.

It got me thinking of what other white flowers were in the yard. And they were legion, including a dwarf Aronia, daisy fleabane volunteers, flowering dogwood, white violets, a spreading white azalea, may-apples, volunteer shrubby honeysuckles, raspberries about to bloom white from their buds, kousa dogwood which bloomed like crazy last year but gets an honorable mention here even though it is taking a year off, a volunteer euonymus, spring beauty wildflowers, and a Korean mountainash Rich Larson of Dawes Arboretum gave me over three decades ago.

And that is just to start. There were highbush blueberries, tiny, creamy bell-like flowers which have great fall color as an ornamental and three of which provide about a gallon of blueberries each year, or rather a half gallon one year and a gallon and a half the next. Fortunately we have good, acid soil.

There was the delightful fragrance and feathery flowers of white fringetree, a tree in the back of our two acres that I ridiculously thought was a small persimmon for a few years after planting.  Emerald ash borer affects this Chionanthus virgincus, a member of the Oleaceae, closely related genetically to its fellow family member, the genus Fraxinus (ashes).  The emerald menace has not affected our fringetree, at least not yet, despite three large mega-infested ashes in our yard we had removed two summers ago.

There are diminutive wild strawberry (Fragaria vesca) plants flowering now. They are more than matched by the beautiful fields of garden strawberries (Fragaria x ananassa) for market just past the western edge of our property, courtesy of the ever-bountiful Rittman Orchard. Come June we shall Go Forth Young Man and Woman, to the U-Pick portion of their business as that most wonderful part of the year begins – the Berry Season.

Back to the woody plants: Bloom on our various crabapples was coming to an end then lo these four day ago, but even the spent blossoms of the Molten Lava crabapple demonstrated the elegance of these lovely flowering trees. Flowering dogwood (Cornus florida) was at the end of its reign in our front yard, but a somewhat wild forgotten area in our northern side-yard yielded a surprise. I had almost forgotten and had to relearn the beauty of the creamy butter yellow buds opening to white four-bracted inflorescences of Cornus alternifolia. Wow.

A lowly “weed” disqualified itself as such, at least for the purpose of this bygl-alert, for I want it for the length of time it takes us to see what this tiny white flower represents. It shows us below its plant family credentials. Common chickweeds (Stellaria media) is in the Caryophyllaceae, which commonly has the characteristic of cleft petals, as seen below, with its five petals superficially looking like ten. Other members of this family include, carnation, gypsophila, and many “pinks”.

Common chicweed

Note: If you want to see a wonderful YouTube of identifying the lawn weeds, common chickweed and mouse-eared chickweed, and the larger woodland wildflower, star chickweed, check out: https://www.youtube.com/watch?v=GJnp-lqdofM

Two of my wife’s favorite woody plants are the double-file viburnum amidst our crabapple grove and the ‘White Tigress’ striped maple overarching our picnic table. The flowers of this infinitely interesting maple (bark, stipules, leaves and leaf venation, form, fall color) are what caught my eye this time. I had not looked carefully at the chain of flowers about to become winged fruits. They have what I predsume to be two prominent exerted styles, the tips of which contain the stigmas receptive to pollen grains and the base being the ovaries which when ovules are fertilized will ripen around the developing seeds and become the fruits.

Doublefile viburnum blooms

Finally two usual suspects, except from a certain perspective. Dent-de lions, the French name chanelling the toothed leaves or lion’s teeth, or dandelions, are certainly beautiful in their blowball stage, though unpopular in this seed-spreading mode. And tiny, cream-white flowers of Rhamnus, also in that wild northern area of the ChatScape. But wait, it is diseased. Alas, not in a killing way: A rust fungus (you will have to wait to see it) that has infected this invasive woody plant. Whither will this fungus go next?  Stay tuned soon for some springtime rust alerts, as we segue from white to orange.

Date Published: May 22, 2018
Authored by: Carri Jagger

The Asian Chestnut Gall Wasp was introduced to North America in 1974 on imported chestnut cuttings. To date it has be identified in Georgia, Alabama, North Carolina, Virginia, Maryland, Pennsylvania, Kentucky, Tennessee and Ohio.

This pest can be distributed throughout the United States by transporting infested seedlings to new areas and by the exchange of infested scion wood used in grafting new trees.

The insect lays its eggs in the buds of chestnut shoots then galls develop on the shoot tips, leaves and catkins.  Nut production and shoot growth are greatly affected by the galls.  Once the adult insect emerges from the gall the dried spent galls become woody and can remain on older limbs for several years.  If the infestation is severe enough it can hurt the overall vigor of the tree and can even cause death.

The adult female wasp is about an eighth of an inch long and they lay a cluster of three to five eggs in the chestnut buds during early summer.  Several adults can oviposit in a bud which could add up to as many as 25 eggs per bud.  Eggs hatch in 40 days with the larvae remaining dormant until the following spring.  When the bud starts to grow the larvae induce gall formation on developing plant tissues.  Before the larvae pupate they feed on the inner gall tissue for 20-30 days.  The adult wasp emerges from the gall in late May to early June.

Management of the pest is very difficult and insecticides are ineffective in suppressing the gall populations.  There are natural enemies that attack and parasitize newly developing galls.  If you have Asian Chestnut Gall you can prune and burn the infested plant material this may slow further movement of this pest.

Information for this alert was derived from the University of Missouri https://extension2.missouri.edu/pa100 and the University of Kentucky http://pest.ca.uky.edu/EXT/ACGW/welcome.htm

Date Published: May 21, 2018
Authored by: Erik Draper

One of the most often asked vegetable questions during this early season is “How soon can I plant my tomatoes and peppers in the garden?”  There are two reasons that the northeast Ohio gardener’s rule of thumb is “wait for Memorial Day” before planting out the tender annuals like tomatoes, peppers and green beans.  The first reason is the possibility of a frost is almost eliminated by waiting until Memorial Day.  Those tender annual plants like squash, tomatoes, green beans and peppers, cannot tolerate a frost event or even lower temperatures at all!

The other reason to wait is that the soil temperatures need to warm up.  Regardless of what daily highs the ambient air temperatures reach, the key limiting factor for early season plant growth is soil temperatures.  The simplest and best way to know when it is time to plant those “prize winning” tomatoes is to buy a soil thermometer and test the soil temperature at about 3-4 inches deep.

Brilliant sunshine, snow showers or cold rains, partly cloudy or completely overcast skies, all serve to impact our soil temperature coming out of the winter season.  It is all about sunshine heating the dark soils, followed by the mostly topical heat layer being gradually moved deeper through the soil profile via conduction.  This is the reason that soils covered with a mulch, are slower to warm up in the spring.  This is due to the mulch acting as a barrier or insulator that prevents the sunlight from directly striking the soil to heat it.

Research studies have provided insight for us to know that tomatoes seem to have problems uptaking phosphorus when soil temperatures, are around or below 50°F.  This lack of phosphorus in young, tomato transplants shows up as a purpling of the underside of the leaves of the plant.  Germination of vegetable seeds is also contingent upon soil temperatures.  This is why peas, radishes, broccoli and other veggies we call “cool-season crops”, have no problem germinating and thriving early in the spring with cooler temperatures.

Put squash, pumpkin, green bean or corn seeds in the ground under those same cool soil conditions and little to nothing happens!  Germination is very slow in these cold, spring soils and the seeds are often overwhelmed by the soil microbes and other decomposers, becoming their source of energy or food.  This is one of the reasons why they are referred to as “warm-season crops”.  The threshold or minimal soil temperatures appears to be about 60°F or higher, which will provide the necessary soil environmental conditions needed by warm-season vegetable crops to grow.

Have some fun in your garden and buy a soil thermometer and track the temperature of your garden soils throughout the growing season.  I think that you‘ll be astounded, amazed and fascinated by what you discover about the temperature trends of your garden soils!

Date Published: May 21, 2018
Authored by: Joe Boggs

Several types of “oak-apple” galls are now obvious on the leaves of their namesake oak hosts in Ohio.  These unusual plant growths range in size at maturity from 1/2 – 2″ in diameter and are named for their resemblance to apples.

Oak-apples are constructed of leaf buds that have been hijacked by a gall-wasp (Family Cynipidae) to surround a single gall-wasp larva located within a seed-like structure positioned at the center of the gall.  The gall structure provides both a protective home and a food source for the developing gall-wasp larva.

Cutting the gall open will reveal the gall’s internal structure.  In general, there are two groups of oak-apple galls:  those with internal tissue composed of a mass of white fibers radiating from the central larval capsule, and those with tissue that strongly resembles the flesh of an apple; it is spongy and juicy.

The so-called Large Empty Oak-Apple Gall is produced by the gall-wasp, Amphibolips quercusinanis (syn. A. inanis).  Galls measures up to 2″ in diameter and arise from leaf buds on scarlet and red oaks.  The gall surface is light green and covered with purplish-red bumps.

The internal structure of this gall is composed of white fibers radiating from the central seed-like gall chamber.  Wasp larvae have chewing mouthparts; so what do the gall-wasp larvae eat? The inside of the gall chamber is lined with specialized cells called nutritive tissue which is constantly being replaced as it is consumed by the gall-wasp larva.  Imagine lounging in a room with pizzas constantly emerging from the walls.

As with all plant galls, oak-apple galls change their appearance once they reach “maturity;” the point where a mature gall-wasp emerges.  In fact, oak-apples are racing towards completing their appointed task this season in the southern part of the state.  They will soon dramatically change color from Granny Smith apple-green to caramel brown.  The mature, brittle galls are called “empty” because the filaments eventually disintegrate leaving an empty gall husk.

There are over 50 species of gall-wasps that are known to produce oak-apple galls in North America and there are probably at least 10-15 distinct species of oak-apple gall-wasps found in Ohio.  Each type of oak-apple is produced by a different species of gall-wasp and their individual handiwork is so unique the galls alone can be used to identify the gall-wasp to species with actually seeing the wasp.

For example, the Small Oak-Apple Gall is produced by the gall-wasp, Cynips clivorum.  This gall forms on the underside of leaf blades as you can see in the images below.  The gall surface is free of any spots or other markings; however, the internal structure is very similar to the Large Empty Oak-Apple Gall.

As with the vast majority of plant galls, oak-apple galls cause no discernable harm to the overall health of their oak hosts.  I believe they actually add ornamental value to their oak hosts, but I may be biased.

The Gall Backstory

Gall formation by wasps and other gall-making insects and mites is a complex and fascinating process that is not yet fully understood.  Thus far, no researcher has ever produced a plant gall without the aid of a gall-maker.

Part of the reason the gall-making process is so complex is because gall-makers produce chemicals that turn plant genes on and off at just the right time to direct gall growth.  The resulting galls provide both a protective home and nourishment for the next generation of gall-maker.

The chemicals exuded by gall-makers can only act upon “undifferentiated” meristematic plant cells.  Under the influence of these chemicals, the meristematic cells that were originally destined to become flowers, stems, or leaves in the case of oak-apples, begin marching to a different drummer.

Once the errant cells fall under the chemical spell of a gall-maker, there is no turning back; they will become gall tissue.  Conversely, this also means that gall formation cannot occur once meristematic cells are committed to becoming “normal” plant tissue.  Once leaves are produced, the leaf cells can’t become gall cells.  It’s one reason the leaf-gall season begins in the spring!

The vast majority of galls found on trees cause no appreciable harm to the overall health of their tree hosts.  Keep in mind that the galls are an outward result of a complicated physiological and chemical dance between the gall-maker and the plant host.

No human has managed to duplicate the work so handily done be a group of organisms that are often viewed with disdain.  If not viewed with a sense of wonder and fascination, at least insect and mite gall-makers should garner begrudging respect.  Imagine the plant secrets that would be unlocked if we could unlock the gall-maker’s secrets?

Date Published: April 9, 2018
Authored by: Jeff Stachler

With these rains the lawn is beginning to grow and the weeds are not far behind.  Some of the earliest emerging broadleaf weeds have begun to emerge.  The biggest problem with weeds in turfgrass is reduced aesthetic value, although some weeds can out compete turfgrass when management is reduced.  Smooth and large crabgrass, yellow foxtail, and annual bluegrass are the most frequent annual grass weeds in turfgrass.

Smooth crabgrass emerges in the spring before large crabgrass.  Smooth crabgrass emergence begins slowly when soil temperatures in the upper inch of soil reaches 54F for seven days and moisture is available.  This 54F soil temperature occurs many times when the dogwood begin to flower and the forsythia flowers begin to fade.  The current soil temperature for Columbus, Ohio is 41F which is 7.6F lower than the 5-year average!  Visit this website to track soil temperature for your area: http://www.greencastonline.com/tools/soil-temperature .  Based upon the current 10 day forecast, crabgrass preventer does not need to be applied until sometime after April 10th and likely much later.  Waiting to apply crabgrass preventer until just before emergence will ensure control of smooth and large crabgrass later into the season.  Peak crabgrass emergence is from mid-May to July 1st.  Crabgrass preventer must be applied before plants emerge, otherwise it will not be effective.  After applying the crabgrass preventer irrigate the lawn to get the herbicide incorporated into the soil.

If crabgrass densities are high, a postemergence herbicide application may be required.  If you have used preemergence crabgrass preventer for many years and have successfully controlled the crabgrass, it may be wise to stop applying the crabgrass preventer and scout to see whether any crabgrass will emerge.  If it does emerge then apply a postemergence herbicide.  Crabgrass can be controlled with some postemergence herbicides, but timing and rate are very important to effectively control crabgrass.  Effective postemergence herbicides include Dimension, Methar 30, Acclaim Extra, MSMA Turf Herbicide, and Drive 75 DF, but some of these may be difficult to obtain.  Acclaim Extra can injure certain bluegrass varieties.  When applying postemergence herbicides be sure to obtain thorough coverage and do not mow for two days before and after the herbicide application.

Date Published: April 14, 2018
Authored by: Joe Boggs

I spotted one of my favorite insect predators darting about on forest trails yesterday:  Six-Spotted Tiger Beetles (Cicindela sexguttata).  Their common name is well justified as these tiny “tigers” hunt, kill, and eat other insects.

The shiny beetles are more emerald green in color than Emerald Ash Borer (Agrilus planipennis) (EAB) causing them to be commonly mistaken for the non-native borer.  Indeed, these tiger beetles have excellent eyesight, quick speed, and they are agile flyers; traits that make it difficult for people to get a close look for accurate identification.

Six-Spotted Tiger Beetles have a curious affinity for hanging out on woodland trails; they can certainly liven up a walk in the woods.  The beetles have elongated bodies with the thorax about half the width of the front wings and abdomen.  They have long legs and their bulging black eyes (the better to see you with, my dear!) make them look like they’re wearing dark goggles.

As the common name implies, six-spotted green tiger beetles have white spots that are arranged along the trailing edge of the wing covers, three spots per side.  The spots are small and sometimes obscured by light bouncing off their highly reflective shiny green bodies.

This ferocious predator sports powerful sickle-shaped mandibles that are used to grab and dispatch luckless arthropod prey; a trait that is shared with other tiger beetles (family Carabidae (Ground Beetles); subfamily Cicindelinae (Tiger Beetles)).  A word of caution:  these carnivores can also use their impressive mandibles to deliver a painful bite to the hand of the overly curious.

Even the larvae of this tiny tiger are predators.  However, instead of actively hunting their prey, they conceal themselves in vertical burrows in the soil to await hapless victims.  When a meat item such as insects or spiders walks past, the tiger larva springs forth like a jack-in-the-box to grab dinner with their powerful mandibles.

The bottom line is that six-spotted tiger beetles are highly effective and important predators throughout their life cycle.  So, keep your eyes peeled for and hands away from these tiny tigers prowling our woodland trails … and don’t kill them since they are good guys!

For More Info:

·         University of Kentucky, Kentucky Critter Files

http://www.uky.edu/Ag/CritterFiles/casefile/insects/beetles/tiger/tiger.htm

Date Published: April 13, 2018
Authored by: Joe Boggs

Boxwoods with light brown to golden brown leaves are common this spring in Greater Cincinnati.  Some of the leaf browning is due to winter injury with foliage at the tips of branches, particularly at the tops of plants or on the windward side of plants, most heavily affected.

Some was caused by salt damage either directly with “ice melt” or rock salt inadvertently thrown onto foliage, or indirectly with “salt spray” carried onto foliage from nearby roadways.  Salt damage is sometimes, but not always, concentrated on wide side of the plant.

However, a close examination may also reveal the telltale blister-like leaf symptoms caused by the boxwood leafminer (Monarthropalpus flavus).  Leafmines may be found throughout the plants although the highest concentration also occurs on foliage at branch tips.

Normally, the blister mines turn brown a bit later in the spring.  However, I’m noticing this year that the blister mines are turning brown much earlier and there appears to be a connection to widespread winter injury.  I’m not certain if winter injury is magnifying the leafmining damage, or vice versa.

Gently separating the upper and lower leaf surfaces (the leafminer had already done most of the work!) will reveal the bright yellow leafmining larvae (maggots) of this midge fly wiggling around in their blister mines.  The larvae will soon complete their development and pupate.  The pupae are also bright yellow at first, but turn orangish-yellow as this stage nears completion.

This non-native midge fly was accidentally introduced into North America from Europe in the early 1900s and is now common throughout Ohio, particularly in the southern and central parts of the state.  Adults emerge at around the same time red horsechestnuts (Aesculus × carnea) and doublefile viburnums (Viburnum plicatum) are in full bloom (440 GDD).  Except for their bright orange abdomens, the adults superficially resemble miniature mosquitoes.

Females use their needle-like ovipositors to insert eggs between the upper and lower leaf surfaces of boxwood leaves.  Each leaf may contain multiple oviposition sites with several eggs per site.  These sites will become individual leafmines producing the blister-like leaf symptoms.

Eggs hatch in early-summer and the resulting larvae spend the remainder of the season consume interior leaf tissue as they develop through the 1st and 2nd instar stages.  Winter is spent as 3rd instar larvae inside the leafmines.  The larvae resume feeding in the spring and develop through a 4th instar stage.

Much of the leaf damage occurs in early spring with the ravenous larvae rapidly expanding their leafmines.  Multiple leafmines in individual leaves may coalesce causing the upper and lower leaf surfaces to delaminate over the entire leaf.  Individual mines may turn reddish-green at this time of the year with heavily mined leaves turning from yellow to orangish-brown causing the leafmining damage to be mistaken for winter injury.

A close examination of the leafmines at this time of the year may also reveal small translucent “windows” created by the larvae in the lower leaf surface.  The pupae will wiggle through these weak points to ease emergence of the fragile adults.

This pupal activity is responsible for one of the most unusual features of this midge fly:  reports of hissing, crackling, or rustling sounds coming from heavily infested boxwoods.  I’ve reported on this strange phenomenon in past BYGLs.  So, reports from gardeners or landscapers that they’ve heard boxwoods going snap, crackle, and pop should be taken seriously as the odd sounds are an indicator of a heavy boxwood leafminer infestation.

Damaging boxwood leafminer infestations can be suppressed through applications of neonicotinoids such as imidacloprid (e.g. Merit, Xytect, Marathon, and generics) or dinotefuran (e.g. Safari, Transtect, Zylam).  However, application timing has been modified in recent years to avoid negative impacts on pollinators.

Boxwood blooms attract a wide range of pollinators; blooming plants can literally buzz with their activity.  Therefore, the insecticide applications must be delayed until AFTER boxwoods bloom.  Some minor miner damage will occur, particularly with the imidacloprid that is taken-up more slowly compared to dinotefuran.  However, this is a small price to pay for protecting pollinators.

You may find recommendations for topical applications of pyrethroid insecticides such as bifenthrin (e.g. Talstar) to target adult leafminer females before they lay eggs.  However, adults typically emerge in Greater Cincinnati while boxwoods are in full bloom, so I no longer recommend this application.

Plant selection provides a more long term solution to the depredations of boxwood leafminer by removing insecticides from the management equation.  A helpful research-based listing of the relative susceptibility of boxwoods to the leafminer was published in 2014 by the American Boxwood Society in their “The Boxwood Bulletin” [see More Information below].

For More Info:

·         American Boxwood Society, Boxwood Leafminer Evaluation

http://www.boxwoodsociety.org/uploads/54_1_2014_Summer.pdf#page=9

Date Published: April 16, 2018
Authored by: Thomas deHaas

Many of the Green Ash trees, Fraxinus pennsylvanica are dying in Perry, Ohio – Lake County. Why?

Green ash is popular as a shade tree in residential areas because of its good form and adaptability to a wide range of sites.

It is susceptible to Emerald Ash borer, an invasive species.

Emerald ash borer (EAB), Agrilus planipennis Fairmaire, is an exotic beetle that was discovered in southeastern Michigan near Detroit in the summer of 2002. The adult beetles nibble on ash foliage but cause little damage.

5449380 Debbie Miller, USDA Forest Service, Bugwood.org

The larvae (the immature stage) feed on the inner bark of ash trees,

5471796 Kenneth R. Law, USDA APHIS PPQ, Bugwood.org

disrupting the tree’s ability to transport water and nutrients.

Emerald ash borer probably arrived in the United States on solid wood packing material carried in cargo ships or airplanes originating in its native Asia. As of August 2017, it is now found in 31 states, and the Canadian provinces of Ontario and Quebec. Since its discovery, EAB has:

·         Killed hundreds of millions of ash trees in North America.

·         Caused regulatory agencies and the USDA to enforce quarantines and fines to prevent potentially infested ash trees, logs or hardwood firewood from moving out of areas where EAB occurs.

·         Cost municipalities, property owners, nursery operators, and forest products industries hundreds of millions of dollars.

http://www.emeraldashborer.info/

Symptoms include defoliation, D-shaped exit holes in the bark,

wood pecker damage (as they hunt for the larvae)

and ‘blonding’, which is large portions of bark that fall off the tree reveal a patch of wood that looks ‘blond’ in color.

A tree that shows severe infestation will die within the year. The danger is these trees soon become a fall hazard and need to be removed before injury or property damage occurs. It is recommended that you hire a tree removal service that is ISA certified and/or bonded.

Now that the Emerald Ash Borer has infested Lake County, Ohio, many Green Ash trees in the landscape and forest woodlots have died. But the real danger is right overhead.

With dead trees and wind combinded, it can be a costly and deadly combination. A tree that shows severe infestation will die within the year. The danger is these trees soon become a fall hazard and need to be removed before injury or property damage occurs.

Our understanding of how EAB can be managed successfully with insecticides has advanced since this bulletin was initially published in 2009. This version has been revised to address frequently asked questions and reflect the current state of understanding of insecticide options for controlling EAB and their effectiveness. It is important to note that research is an ongoing process. Scientists from universities, government agencies, and companies will continue to make discoveries and advance EAB management and ash conservation.

http://www.emeraldashborer.info/documents/Multistate_EAB_Insecticide_Fact_Sheet.pdf

Date Published: April 10, 2018
Authored by: Joe Boggs

Last Friday, Larry Parker (Cincinnati Parks) sent to me the images below of Boxelder Bugs (Boisea trivittata, order Hemiptera) hanging out on a park building.  ‘Tis the season.

These boxelder bugs didn’t fly to the building this spring; they were already there.  This fall home invader overwintered somewhere in the building (walls, attic, etc.) and spring temperatures are beginning to roust them from their winter barracks.  The bugs were clustered as they awaited outdoor temperatures that will support their flight; they were gone from the building as of yesterday.

The bugs Larry photographed had successfully made their way outside, but this is not always the case.  Occasionally, they become confused by warm indoor temperatures and find their way into homes and other structures.  They don’t bite or represent a threat to anyone or anything inside a structure, but they can be serious nuisance pest as they frantically crawl or fly around looking for a route to the great outdoors.

This is the first report I’ve received this spring of boxelder bugs emerging from their overwintering sites.  However, with the predicted warm-up this week, I’m sure this is just the beginning.

We can also expect other fall home invaders to soon make their spring appearances.  These include Western Conifer Seed Bugs (Leptoglossus occidentalis); Multicolored Asian Lady Beetles (Harmonia axyridis); and the notorious Brown Marmorated Stink Bugs (Halyomorpha halys).

Boxelder bugs range in size from 1/2″ – 3/4″ long.  They are narrow-shaped, flat-backed, and dark gray or dark brownish-black.  They have three highly visible orangish-red stripes running lengthwise on the pronotum, the area behind the head; “trivittata” is Latin for “three-striped”.

The bugs are seed-feeders and are so-named because of a strong association with Acer negundo; however, both the adults and nymphs will commonly use their piercing-sucking mouthparts to draw juices from the seeds of other trees in the Acer genus.  They have also been observed feeding on alder, apple, buckeye, cactus, geranium, grape, honeysuckle, lilac, linden, oak, peach, plum, spirea, strawberry, and tulip.  I’m aware of boxelder trees being cut down in an attempt to eliminate the bugs; however, their wide-ranging feeding activity illustrates why this management effort may fail.

The best offense against these and other fall home invaders buzzing or lumbering around inside homes and other structures is a strong defense.  Large openings created by the loss of old caulking around window frames or door jams provide easy access into homes.  Such openings should be sealed using a good quality flexible caulk.

Poorly attached home siding and rips in window screens also provide an open invitation.  The same is true of worn-out exterior door sweeps including doors leading into attached garages; they may as well have an “enter here” sign hanging on them.  Venture into the attic to look for unprotected vents, such as bathroom and kitchen vents, or unscreened attic vents.  While in the attic, look for openings around soffits.  Both lady beetles and stink bugs commonly crawl upwards when they land on outside walls; gaps created by loose-fitting soffits are gateways into home attics.

For More Info:

·         University of Minnesota Fact Sheet

https://www.extension.umn.edu/garden/insects/find/boxelder-bugs/

Date Published: April 7, 2018
Authored by: Joe Boggs

Why in the name of all that is horticulturally holey do we continue to see mulch piled around tree trunks to stratospheric heights?  What is the appeal?  And, why can’t we stamp out these mulch monstrosities despite years of educational efforts?

The image below was taken 20 to 25 years ago by Jim Chatfield using a 35mm camera.  It shows Erik Draper’s size 12 shoes positioned to illustrate mulch piled over 2 feet high. The three of us used this image for years in numerous training programs to teach against this horticultural horror (volcano mulch, not Erik).

Of course, there have been numerous efforts by other Extensioneers, Master Gardeners, and our Green Industry to educationally eradicate mulch volcanoes (a.k.a. mulch mounds).  There has been some success.  I can count on provoking groans from audiences of horticulture professionals or Master Gardeners by showing them pictures of mulch volcanoes.  The impact is so profound, I commonly hear groans lingering throughout my presentations!

And yet, mulch volcanoes continue to erupt.

Indeed, this mulch rant was incited by a visit to a local hospital yesterday where my wife had a minor medical procedure.  Nothing serious, but I spent the wait-time cruising the hospital’s landscape.  Unfortunately, the most striking feature was new mulch formed into high mounds:  mulch volcanoes were erupting everywhere!

Adding insult to injury was the peculiar practice of digging a “mulch moat” around the base of the mulch stratovolcanoes.  Creating these mulch moats not only cuts existing tree roots extending into the surrounding soil, but the trench can prevent root regrowth into the soil beyond the moat.  In essence, each tree has its entire root system confined to the area beneath its mulch volcano.  ARRGHH!

I’m certain the hospital is staffed by some of the best medical professionals in our region.  However, as visitors and patients approach the hospital, they are greeted by clear evidence of far less than professional horticultural practices.

When It’s Done Right

Organic mulches such as aged bark mulch are a wonderful thing.  They moderate soil temperatures, preserve soil moisture, suppress weeds, and as the organic mulch slowly decays, it contributes to the organic content of the underlying soil.  The dark color of natural bark mulch also enhances landscape aesthetics.  Of course, the availability of organic mulch dyes makes other colors available; shopping for mulch can be like using an artist’s palette.

Last season, I highlighted an exemplary use of mulch in Glenwood Gardens, Great Parks of Hamilton County (see BYGL April 27, 2017, “Glenwood Gardens: A “Volcano” Mulch-Free Zone”).  They had followed all of the general recommendations for the proper use of hardwood mulch around trees.  The mulch rings were as large in diameter as practical and mulch depths were no more than 2 – 3 inches.  Mulch that found its way onto the tree trunks was pulled away from the trunk flare.

When It’s Done Wrong

Volcano mulch does not kill trees outright; if it did, people wouldn’t do it.  Instead, it produces subtle, long-term, ill-effects.  Although bark mulch may at first appear light and airy, it will ultimately compact as it degrades to interfere with oxygen reaching tree root cells.  Trees respond by growing roots into the mulch; however, the roots can become exposed as the mulch further degrades.

The slopes of mulch volcanoes cause roots to turn; they can’t grow into thin air!  Eventually these roots encircle the tree trunk and merge with the stem tissue.  As these errant roots increase girth, they gradually girdle the trunk and restrict vascular flow.  Thus, they are known as “stem girdling roots.”

As the mulch decomposes and dries out, it will eventually start to repel water; it becomes hydrophobic.  You can observe the hydrophobicity of dry organic matter when you try to moisten a bag of dry peat moss.  Of course, water repellency ultimately causes roots that have grown into the mulch to dehydrate.

The deleterious nature of volcano mulch is not immediately apparent.  Moisture starvation and vascular strangulation can ultimately kill a tree; however, along the way they produce tree stress.  This can induce trees to drop their defenses against infestations by opportunistic insect pests such as native borers or infections by plant pathogens.  Of course, pests and diseases get blamed if trees succumb, not the volcano mulch that made the trees susceptible in the first place.

William Shakespeare, in King Henry VI, Part III, provided the perfect quote:

“And many strokes, though with a little axe,

Hew down and fell the hardest-timbered oak.”

Volcano mulch is a little axe.

Date Published: April 6, 2018
Authored by: Amy Stone

Hairy Bittercress (Cardamine hirsute)

While temperatures remain cold, and even an occasional snow flake takes flight, there is weed that is giving it is all this spring. That weed is hairy bittercress. While it has been lurking in gardens all winter long, it is flowering its little heart out and setting seeds right now in northwest Ohio.

This weed sends out leaves in a basal rosette from seeds that germinated last year. Like other members of the mustard family (Brassicaceae), its tender greens are edible. You might be fooled by the common name—the plant is typically not bitter, but rather peppery in taste. Its flowers can be tough to chew, but the tender leaves are said to be a source of vitamin C, calcium, magnesium, beta-carotene and antioxidants.

Speaking of flowers, hairy bittercress produces a small cluster of tiny flowers each with 4 white petals. Narrow seed pods stand tall above the flowers. When dried or disturbed, the seed pods “explode” sending seeds in all directions.

This seed dispersal strategy is known as ballochory. Jewelweed and cranesbill also employ this as a strategy to spread seeds.

Removing plants prior to them setting seed is highly recommended. In northwest Ohio you will have to move pretty quickly as it doesn’t take much time for the seeds to develop. The use of a pre-emergent herbicide can help reduce future populations. Hairy bittercress can be a nuisance in the landscape, turf, greenhouse and nurseries.

Date Published: April 6, 2018
Authored by: Joe Boggs

Driving south on I-71 Wednesday, I was mesmerized by a deep purple veil creeping across fields like smoke on the water.  The purple haze, all in my eyes, made me wanna drive ’til I ran out of highway into the purple sky.

The annual bloom of Purple Deadnettle (Lamium purpureum) that is just getting underway in farm fields flanking Ohio’s southern highways was responsible for my nostalgic pop culture smash-up.  Even this weed’s name would be great for a rock band; think Deep Purple meets deadheads.

Purple deadnettle is a winter annual meaning that seeds germinate in late summer to early fall.  Members of this sneaky group of weeds grow throughout the winter and sing their flower song in the spring.  This isn’t a problem for farmers because winter annuals are easily plowed under in the spring so they don’t compete with summer annual crops.  In fact, in some ways, they act like winter cover crops.

However, winter annuals can create headaches for landscape and turfgrass managers.  Since preemergent herbicides are typically used to target the spring germinating seeds of summer annuals (e.g. crabgrass), winter annuals such as deadnettle can escape to reappear as harbingers of spring each year.

The beautiful purple display beginning to adorn Ohio farm fields is produced by both the flowers and new leaves of purple deadnettle.  The pitcher-shaped flowers range in color from pink to deep purple.  Older leaves are green to purplish-green while new leaves may be a deep, reddish-purple.

Henbit (L. amplexicaule) is sometimes mistaken for purple deadnettle, and vice versa.  Both are winter annuals and since both are members of the mint family (Lamiaceae); they have square stems.  However, henbit leaves are scalloped and evenly spaced along the stem; new leaves do not have a purple hue.  Plants tend to grow low to the ground and are seldom so prolific they cover large expanses of open ground.

The leaves of purple deadnettle are triangular to heart-shape and serrated along the margins.  They arise opposite of one another along the stem and new leaves may be deep purple.  Deadnettle plants may rise to height of 16 – 18″ and they commonly carpet open ground such flower beds, openings in weakened turfgrass, and of course farm fields.

Purple deadnettle can be controlled by hand weeding and cultivation.  A post-emergent broadleaf herbicide can be applied in early spring to control the blooming plant, but a pre-emergent herbicide will need to be applied in late summer to control the germinating seeds of this winter annual.  If you do choose to use an herbicide, be sure to follow and read all label directions.

Date Published: April 2, 2018
Authored by: Joe Boggs

Our slowly developing spring is a real boon to us procrastinators.  If you exercise caution by performing a close inspection of what lies beneath, there may still be time to make a non-selective herbicide application to control Poison Hemlock (Conium maculatum) without wiping out preferred plants that have not yet sprung for spring.

Poison hemlock is certainly a worthy target for early spring herbicide applications.  It’s one of the deadliest plants in North America.  You don’t want this nefarious non-native invasive weed flourishing in landscapes where people; particularly children, can come into contact with the sap, seeds, foliage, or roots.  It’s no exaggeration to say the outcome could be lethal; consider Socrates.

Death in a Tea Cup:  A Greek Tragedy

The plant contains highly toxic piperidine alkaloid compounds, including coniine and gamma-coniceine, which cause respiratory failure and death in mammals. Indeed, the infamous demise of Socrates is testament to the lethality of poison hemlock.  Plants and seed were imported to North America as an ornamental from Europe and West Asia in the late 1800s.  Unfortunately, this dangerously toxic plant is now common throughout much of Ohio.

The toxins must be ingested or enter through the eyes or nasal passages to induce poisoning; they do not cause skin rashes or blistering.  Regardless, this plant should not be handled because sap on the skin can be rubbed into the eyes or accidently ingested while handling food.  While the roots are more toxic than the leaves and stems, all parts of the plant including the seeds should be considered dangerous.

Death-Defying Identification

Poison Hemlock belongs to the carrot family, Apiaceae (formerly Umbelliferae).  It shares a number of characteristics with the non-native but non-toxic Queen Anne’s Lace (Daucus carota) as well as the non-native Wild Parsnip (Pastinaca sativa) which is notorious for producing sap that causes skin blisters through phytophotodermatitis.

All stages of the poison hemlock plant have bluish-green leaves that are 3-4 times pinnately compound, and the deeply cut parsley-like leaflets have sharp points.  Flowering plants have hairless, light-green to bluish-green stems that are covered with obvious purplish blotches.  Clusters of tiny white flowers are borne on structures called umbels that look like upside-down umbrellas.

Turning the Tables:  Poisoning Poison Hemlock

Poison hemlock has a biennial life cycle and spends its first year as a basal rosette; the stage that is currently very apparent.  During its second year, plants produce erect, towering stalks and multi-branched stems topped with umbrella-like flowers.  Mature plants can measure 6-10′ tall.

Poison hemlock can be managed by mowing and tilling; however, the most effective control and perhaps safest relative to avoiding the sap focuses on properly timed herbicide applications.  Non-selective herbicides, such as glyphosate (e.g. Roundup) or pelargonic acid (e.g. Scythe), applied now can eliminate the first season rosette stage and the second season flowering stage, before seeds are produced.  Selective herbicides, such as triclopyr (e.g. Triclopyr 4, Ortho Poison Ivy and Trough Brush Killer) or clorpyralid (e.g.Transline), may also be applied now, but are generally more effective once plants start initiating the flower stalks.  Of course, as always, you must read and follow the label directions when using any herbicide to maximize safety and product efficacy.

Invasive Species Awareness Week – ORIENTAL BITTERSWEET – Invasive Species of the Day

National Invasive Species Awareness Week – GYPSY MOTH – Invasive Species of the Day

National Invasive Species Awareness Week – Japanese Knotweed – Invasive Species of the Day

Wonderful Witchhazels Welcome Warmer Weather

Silver Maples Blooming Away

National Invasive Species Awareness Week – KUDZU – Invasive Species of the Day

As Temperatures Warm, Don’t Forget Growing Degree Days