It’s an often-observed phenomenon – the happy accident. Creativity thrives on finding the virtue in a mistake, and turning it into a triumph. This vertical arrangement of Corydalis and Nepeta, growing through the cracks in a weathered retaining wall in the Elizabeth and Nona Evans Restorative Garden, is a thriving, utterly unintentional example of the latest trendy craze – the green wall. And they planted themselves!

Green walls can demand careful engineering to ensure that their living facade will survive and stay decorative. Northern Ohio winters spell certain death for unprotected roots, while the summer sun  and wind make expensive irrigation systems a requirement. The most practical "living wall" in this climate is probably the most natural: a vine, rooted in the earth, and reaching for the sky.

Back to our "unintended consequence." These two self-sown companion plants have taken advantage of the other type of "living wall" design that has potential for the Ohio climate. Earth-backed retaining walls like those along highways and interstates have the insulated root zone, and natural water-holding capacity that makes for succesful vertical plantings. The fact that they bloom together in a nice complementary color palette is just icing on the cake.

Posted by Ann McCulloh

It’s raining today. And cold. It makes me want to nap. But it is also so beautiful outside right now that it makes me want to garden. I think the colors outside are amazing during this kind of weather and I spend a considerable amount of time staring out windows during spring showers.  I may not want to admit that during the work day, but it’s the truth.  So considering the weather, rain gardens come to mind. If you have an area in your yard that regularly holds standing water, you may want to consider installing a rain garden. Good old Wikipedia says that “a rain garden is a planted depression that allows rainwater runoff from impervious urban areas like roofs, driveways, walkways, and compacted lawn areas the opportunity to be absorbed.” A rain garden prevents soil erosion, decreases the water emptying into storm sewers and looks great in the process. The Cuyahoga Soil and Water Conservation District has fantastic resources on their website for rain garden installation and has a kit with all the plants needed for a 100 square foot garden available for purchase. The manual from their website is the best I’ve seen on rain garden installation.  In our library, we have a book called Rain Gardens: Managing water sustainably in the garden and designed landscape. (Why do all books nowadays have to have such long titles? What gives?) In looking through this book, I realize that I need to be careful about information I take from books. This is potentially a very useful book. In Great Britain. The two authors hail from the UK and give many examples and pictures from rain gardens in Europe, which is all fine and well and good. My problem lies in the chart of rain garden plants at the back of the book. At first, I’m all excited – I love lists! And they tell me exactly what I need to know without a ton of reading. But then I see they recommend purple loosestrife, even noting that it can be incredibly invasive. So why are they recommending it? I would never, ever recommend planting purple loosestrife so this book’s value and credibility decreases tremendously in my opinion.  Lastly, we have just broken ground on our very own rain garden here at the Garden which will be complete by the end of May. It is located adjacent to the Woodland Garden and will be a great visual enticer for you to install one of these beauties in your own landscape. This rain garden is being installed as I type this; stop by the check it out, or stay tuned to this space for enticing documentation of this important new garden.

Tale One: Big Tree, Big Axe.  Cleveland Botanical Garden has a row of maturing, healthy Norway maples (Acer platanoides) growing along East Boulevard.  And we are cutting them down.

Actually native to Norway and across northern Europe, the Norway maple has a detailed association with humans.  If never a lumber tree, it has long been valued for fine carpentry and horticulture.  In early 1700s Italy, Antonio Stradivari probably made the back boards for his supreme violins from Norway maple.  By the mid 1700s Norways had crossed the Atlantic to appear in Colonial seed lists; there is a 1756 record of one being planted in Philadelphia.  Norways were popular in 1800s New England as garden fancies (curiously, all our trees came from English nurseries, where Norway maple is non-native, so we have no wild provenance on  U.S. stocks).

But it took Dutch elm disease of the 1930s to bring the Norway maple to its current prominence in the northeastern U.S.  This disease that devastated our native American Elm (Ulmus americana) created a huge void in our street tree population, a void that was filled by existing nursery stock in the form of the Norway.  And it was a good elm substitute, for it was found to be easy to commercially re-propagate in a hurry, to transplant well, to grow vigorously on site, and to have tremendous tolerance of urban environments.

But the Norway also makes impenetrable canopy shade, throws copious fertile seed, and chemically inhibits competing seedlings. This suite of traits both “good” and “bad” soon helped the Norway become—you guessed it—a woody weed.

So here at the Garden, we had three Norway maples removed (I can’t say “felled” since they were hoisted up from their stumps and craned out of the garden) the week before last.  In the coming years, more will be removed.  And we already have a plan for the sunny slope they are leaving behind.  Our Woodland gardener has selected a swath of flowering shrubs, small trees, ferns and wildflowers to grow and thrive in this space.  The emphasis is on native plants, but there are exceptions; the design is naturalistic, but with an artistic gleam.  So watch this space with some anticipation.  Coming soon are flame azaleas and rosebay rhododendrons, native silverbell and spirea, hay-scented fern and fragrant sumac; a hillside painting in the sunshine.

Look around you.  If you have an ornamental maple in your yard with burgundy, bronze or chartreuse foliage, it is a Norway hybrid.  I don’t loathe the Norway so much as respect its potential.  Like all weeds, to me it is half-terror, half-teacher.

Tale Two: Big Tree, Small Axe.   Cleveland Botanical Garden has a nice Chestnut Oak (Quercus prinus) at the edge of the Restorative Garden, and right now it is dropping twigs damaged by a girdling beetle.

The flat-headed longhorn oak girdling beetle (poss. Oncideres quercus) probably won’t kill the tree.  But over the past few years of infestation it has already disfigured its twigs, by inducing hundreds of haphazard, zigzag re-growths.  And I have been taught by experience that one tree stress often invites others, which add up to sometimes deadly arithmetic.

This beautiful little creature wears wing covers that look as if they are made from hammered lead, and sprouts segmented, elegantly curved antennae that extend from flat head halfway to pointy tail.  It leads a peculiar and particular life.  The little twig tips littering the ground today were fashioned last autumn into nursery chambers by the adult beetles.  The adults chewed “girdling” rings into their twigs, and then laid a few to a few dozen eggs under the bark of each of their outrigger twigs.   The adults soon died, but their eggs hatched within the twigs, and spent the winter as larvae, nestled and safe up in the tree.  With this spring’s winds and rain, the girdled—and killed—twigs are now snapping free from their moorings, and falling to the garden floor.  And it is down here that the oak girdling beetle larvae begin to feed for a few weeks, eating their nursery walls.  They then pupate, again in their original twig chambers.  By mid-summer, the flying adults will hatch, eat some green wood, mate, and girdle more living chestnut oak twigs to complete their annual life cycle.  I will collect some twig tips, keep them contained, and see if I can capture one of the hatching adults this summer.  If successful, I will post pictures here.

Common in Ohio, I see evidence of the oak girdling beetle every year in chestnut oaks, white oaks (Quercus alba), and bur oaks (Quercus macrocarpa), too.  Bur oak twigs snap off a few months from now; is the wood perhaps more durable, or does bur oak bear a different species of beetle?

If you have girding beetles living in your oak, don’t fret.  Tend to the tree’s general health and it will withstand the infestation.  Don’t compact your oak tree’s soil or cut its roots, and don’t mulch it too heavily.  Prune damaged wood that might invite secondary disease.  And collect and destroy all the fallen twigs, so removing the next generation of beetles in the process.

Oaks have co-evolved along with a host of voracious native insects.  For their half of this never-ending pull-and-tug, oaks manufacture an array of tannins and possibly lignins for chemical defense. Nevertheless, an oak un-blighted by apple gall wasps, oak leaf rollers, or girdling beetles seems unusual to me.  They must be generous trees, and surely the flat-headed longhorn oak girdling beetle is fortunate for this bounty.

There you go: Two Cutting Tree Tales; Or, What I Saw In The Garden.

Posted by Mark Bir 
 

 This world can sometimes be a little chaotic. But there is no reason that needs to spread to your garden. Harmony is the design concept that ties things together. It may be the repetition of colors, shapes or textures or a unifying theme employed throughout the garden. It is an important principle that tells the visitor that the space makes sense and is pleasing to view.

Containers give the gardener a lot of creative options to achieve harmony. They are portable and easily changed out to complement whatever is going on in the beds. Here is an example of tulips in containers that match the display in the bed. This of course was conceived in the fall when bulbs were planted in the bed. The same tulips were also planted in nursery pots and sunk in the ground. This works better than planting them directly into above-ground containers that experience frequent freeze/thaws throughout the winter. The ground insulates them from wide temperature fluctuations and helps them develop in sync with the bulbs in the bed.  In the spring the nursery pots are simply lifted and placed in the containers to provide an arrangement that harmonizes with the display in the bed.

Posted by Bob Rensel

Now here is a fascinating twist on the same old story.  We find a noxious weed running rampant across our landscape, doing its evil and “blah, blah, blah" — but lo — it is not all bad.

Meet the bad Japanese knotweed (Polygonum cuspidatum). This beast of a weed has a playbook full of dirty tricks: running, re-propagating rhizomes; wide soil and salt tolerance; no pests or diseases; canes and leaves that grow fast and tall to crowd out native plants.

“But wait!” Meet the good Japanese knotweed. This beauty of a weed may also have a good heart: powerful, “age-reversing” anti-oxidants; resistance to some cancers; protection against heart disease and diabetes; cholesterol reducing properties; Alzheimer plaque-blocking properties.

So what’s the real story?

Knotweed has a human history more subtle and complex than “weed.”  It begins back in its native land, where Hu Zhang is the epithet for powdered knotweed root in traditional Chinese herbals. For centuries, it has been prescribed as an analgesic, diuretic and expectorant, to treat bronchitis, jaundice, and hypertension. Western medicine has recently isolated and identified a powerful antioxidant from the entire plant as the probable active ingredient in knotweed. This fairly small, 14-carbon organic molecule has no common name, so we’re stuck with “trans-resveratrol.”  But I am going to practice pronouncing it, because it’s the same heart-healthy stuff found in red wine at the crux of the French Paradox, but at 80 times the concentration.

Knotweed synthesizes trans-resveratrol as a sort of botanical immune response to fungal and bacterial pathogens, even making larger quantities in moldy springs.  The chemical apparently acts to absorb harmful free radicals released during knotweed’s argument with pathogens.  This is why trans-resveratrol intrigues us moderns, for it displays substantive ability which hints that it may transfer well to the realm of human health and disease.  Its appeal leaps beyond fringe healing to find interest amongst some of the best minds practicing conventional medicine.

Current knotweed research is probing trans-resveratrol’s capacity to interrupt free-radical cascades in the electron transport transport chain of cell metabolism, to block carcinogenesis, to interfere with plasma LDL and its role in atherosclerosis, and to indirectly activate our sirtuin genes and so mimic the inhibitory effect of caloric restriction on aging. And that’s just some of it. Phew.

Here is where the story leads us to Cleveland Botanical Garden. Lately, we can find the asparagus-like shoots of Japanese knotweed bunched at our market stands, for sale as a tonic comestible.  And since last September, the Garden and I have been providing modest technical assistance to Lynne Thompson of Ohio Magazine, to forward her research for an April, 2010 article exploring knotweed as a constituent of a healthy cuisine (www.ohiomagazine.com/Main/Articles/Asian_Invasion_4153.aspx).  It is a good article; good work, Lynne.

“Technical assistance” has amounted to me attempting to grow some knotweed indoors to produce an out-of-season winter shoot crop.  Lynne wanted to bake a knotweed pie!  So, being a hungry man, I wild-collected seeds and rhizomes, and potted both in our working glasshouse.  But this was to little avail, for both propagules (hi-falutin’ word for germinate-able tissue, be it seed or shoot or root) were already locked into their seasonal dormancy cycle.  The seeds simply sat. The rhizomes sent up weak sprouts and leaves, which lingered but did not grow in manifest until February.

No pie. Lynne’s article went to press, complete with a tantalizing description of knotweed pie, but still, no pie. Being a determined girl, Lynne convinced me to nevertheless help her see this project through, go out this spring and harvest a pie-worthy mess of knotweed.  After I agreed to round two, she cleverly added, “and do you know where we can find some of the stuff?”  Deciding my continuing promise of pie was worth this new effort, I quizzed the Garden Green Corps staff, who just happened to have some knotweed growing on their Fairfax Urban Learning Farm (http://www.cbgarden.org/Green_Corps/Learning_Gardens.html).  For a small inferred bribe involving chocolate or alcoholic beverage, I was soon granted privilege to escort Lynne there on a harvesting expedition.

Knotweed season is well upon us, so after a flurry of phone tag, we hurriedly set last Friday morning for the big harvest.

Lynne brought along a surprise guest.  “Hi, I’m Mike,” was his unpretentious-as-a-howdy greeting for me.  It took Lynne to explain that it was “Mike” as in “Dr. Michael Roizen,” director of wellness programs for the Cleveland Clinic Foundation.  If serendipity was my sensation at shaking hands with this man whose wellness books are dog-eared on my library pile (this handshake alone makes me 1.3 years younger), I was also unsurprised that he was curious to see knotweed in situ.

The harvest went without incident, aside from giving me the pleasure of watching two informed and intelligent people express such optimism for this weed that mostly causes me and my peers to hyperventilate. It was refreshing and instructive.  Seeing them with their open eyes has prompted me to ponder anew the ecological/social dialectic between weeds and people.  Without trying to put too-fine a point on it, it has given me intent to see weeds not as the enemy, not as bad or good, but simply as living things put out of place. If we have made knotweed into a weed with a capital W, it seems to me that it would be a second slip to destroy it with no consideration for its unknown potential.

Trans-resveratrol may not prove to be the fountain of youth that we hope it to be, but the lesson is still true.  Knotweed, having interacted with us for generations across continents and societies, teaches me about us as much as about itself. 

And to me, that’s the real story.  Knotweed isn’t so easy to loathe, after all.  We need to control this weed, and we especially need to control ourselves.  Villain and healer wearing one mask, I look at Japanese knotweed and see myself in the mirror.

It was nice to meet ya, Mike.  And if you see Lynne, please tell her I’m still waiting for my knotweed pie.

Posted by Mark Bir

              Ahh, spring . . .  so many beautiful shrubs, trees, and flowers coming into bloom, many filling the air with such delightful aromas that it makes you want to go up and smell each and every flower. That is, until you come across one of those beautiful white flowering trees that seem to be planted everywhere – and before you can even approach the tree you are overwhelmed with a terrible, somewhat fishy smell that just turns your stomach.  

      That beautiful white tree is the ornamental pear tree, Pyrus calleryana. It is a very commom tree in the landscape, especially as a street tree, because of its medium size, attractive narrow form, and its relatively low cost.  Its biggest drawbacks are usually considered to be that many cultivars are either prone to fireblight, or tight branch angles, or both. Narrow branch angles cause weak points in the tree structure and can cause large limbs to split from the tree and ruin its form. In my opinion, this tree’s biggest offense is the horrendous smell of its flowers. They have such a strong scent that there have been times when that I identified a pear tree’s prescence before acutally seeing it. So, if you are wondering why your yard has that terrible odor every spring, look around for a tree covered in white flowers and you’ll know.

     Ornamental pears aren’t the only smelly trees. Soon after the pears flower, the hawthorns begin to flower. They have a very similar smell, but not quite as strong. Plus, they are not nearly as common. Probably the worst offender is the ginkgo tree, Ginkgo biloba. It’s not the flowers that smell in a ginkgo – in fact ginkgos are not flowering plants. It is the fruits that fall in early autumn.  The fruits contain buytric acid, a chemical also found in vomit, which is exactly what the rotting fruits smell like. Luckily, the trees are dioecious and you can plant a male tree with no fruits.  

       If you can’t stomach the smell of ornamental pear but still want a nice spring flowering display, perhaps a good alternative would be a flowering crabapple. They are also very common landscape trees, but come in such a wide variety of colors, shapes, and sizes that I wouldn’t call them overused. Many cultivars also have attractive colored fruits in the fall, unlike ornamental pears which only have small brown nubs of fruit that go unnoticed by most.  A second option would be serviceberry, Amelanchier sp.. These medium-sized trees have showy but short lived flowers in early spring with edible berries in early summer. For more information on serviceberries, check out one of my earlier blogs here.  

Posted by Nate Tschaenn

Spring is in full swing. Clusters of crabapples, swaths of tulips, bobbing daffodils and sweet-scented hyacinths make that abundantly clear! The Woodland Garden floor is carpeted with trillium, twinleaf, wood poppy and bluebells. It’s a sight to see, a Technicolor marvel complete with twittering birds and buzzing bees.

But other, humbler delights await the curiosity-seeker. A favorite spring flower of mine is concealed by curvaceous heart-shaped leaves, just inches above the ground. Wild ginger (Asarum canadense) is a delightful native wildflower that few people ever see blooming.

Its softly fuzzy maroon flowers actually rest on the ground, cushioned by fallen leaves. The open throat is an invitation to certain types of flies, which shelter there from cold weather and feast on the pollen. Although the flowers can self-pollinate, the flies also provide this service. Later on when the seeds develop, they are dragged away and buried by ants.

Despite the name and spicy-scented roots, wild ginger is not related to the Asian culinary ginger (Zingiber officinalis). It was candied or dried and made into syrup by early settlers, but that use is now discouraged due to possibly toxic compounds.

However, its use as a bandage for wounds by Native Americans has been supported by the recent discovery of antibiotic properties in the plant.

Wild ginger makes a pretty groundcover for shady or wooded spots. And the hidden flowers are another reminder of the wonderful complexity and sublety of the natural world. Wild ginger blooms in the Woodland Garden in April or May.
 

Posted by Ann McCulloh

We have a new visitor to the Garden.  But this one has six legs, mandibles and compound eyes, and is most unwelcome.

The viburnum leaf beetle (Phyrrhalta viburnii) is here, and we are in danger of losing much of our flowering viburnum collection to its hunger.  Why is it such a problem?  Because the “VLB” has been introduced inadvertently to North America without any of its natural checks and balances, and so is free to chew its way through our wild and garden viburnums.  Not only that, it comes with a one-two punch, since both the larvae and adults feed on viburnum leaves.

A European native, this inconspicuous brown beetle—1/5” long—was first noticed in Canada about 1947 (possibly it was a hitchhiker on garden viburnums shipped from overseas].  VLB has since been making its way through the east; in 2000, it was verified in western PA and parts of Ashtabula County; by 2008 it was verified in Lake and Cuyahoga Counties.  We found it on some of the Garden viburnums this summer.

What is a gardener to do?  We could slather our viburnums with potent organophosphate insecticides, which would certainly kill VLB, along with all the other local arthropods, good and bad in the same basket.  We could do nothing, be totally organic, let the beetles have their way, and supplant infested viburnums with different flowering shrubs.

Or we could choose a hybrid approach.  If we made the effort to study VLB/viburnum interactions, we might then be able to design a modified organic control plan that selects mechanical and biological controls, but also permits least-toxic chemicals when absolutely needed.

Sounds like a pretty good idea!  Let’s walk through the hybrid “education and action” plan that we made for our VLB infestation.

As these things often go, VLB has learned to favor our smooth-leaved viburnums, especially arrow-wood (Viburnum dentatum), over the hirsute varieties it had back home.  Maybe it’s like eating nectarines instead of peaches? A Garden walk-about confirms this, so we decide to focus on arrow-wood, and simply monitor other viburnum varieties for VLB. This saves us effort and possible pesticide use; if other viburnums begin to show VLB damage, we’ll adjust protocol.

We also decide to provide complete cultural care to all our viburnums, to reduce their overall stress and so help them survive VLB.  This is a simple matter of composting and mulching in spring, and irrigating during possible summer dry spells.

Next, we consider the VLB life cycle, since it will help us discover when the beetle is most vulnerable.  VLB lays eggs by drilling into viburnum first- or second-year branch tips in early autumn; the eggs over-winter under the bark and hatch by early May; the larvae eat leaves, and then crawl down to the soil to pupate by early June; the adult beetles emerge by early July, eat leaves, mate, and complete the annual cycle. VLB presence is  betrayed by two identifying clues: "sewing machine" egg scars on dormant twigs (see photograph); buckshot feeding holes in the leaves starting in late spring.

Well, what is the best stage to arrest VLB?  We decide to go after the eggs, since they’re easy to catch!  A mechanical control method will work.  So, right now in early April, we are tip-pruning egg-laden young twigs from infected arrow-wood plants, and away from their future feeding bushes.  This is a good choice, since viburnums respond well to pruning, and will not suffer a loss of vigor.

In our highest visibility gardens, where viburnums need to be cosmetically perfect, we will forgo tip-pruning, and choose from two chemical control options.  First choice is an April spray of summer horticultural oil, which is essentially liquid candle wax.  Hort oil is topical, smothers the eggs, and does minimal harm to beneficial arthropods. Second choice is granular imidacloprid, a synthetic nicotine that is applied to soil and translocated from the roots to the young leaves, where it kills the feeding VLB.  Used like this, it also doesn’t harm predatory beneficial insects.

We will attempt to get by with just the early spray of benign hort oil.  If this is unsuccessful, next spring we’ll go for the nicotine.

Oil can also kill the larvae, but timing is more finicky.  Killing the adults requires stronger broadcast chemicals, and by their advent it is too late anyway to prevent leaf damage by the hungry spring larvae.

There it is.  We studied the plant and the insect, and used what we learned to pick a suite of smart, safe control methods for our VLB infestation.

There’s a name for this approach to pest control.  It is “Integrated Pest Management,”  or (here comes another acronym) IPM.  Local biological systems are kept intact, to buffer against future pest explosions.  Plants are grown with the grace of their unique nature in mind.  IPM views the garden as a whole, and not merely as a game board of plants vs. enemy insects and diseases.

The threat to Ohio’s wild and garden viburnums is real, and may even prove devastating.  Please monitor your viburnums for VLB damage, and be ready with IPM thinking.  Integrated Pest Management: control the pest without crushing the garden.

—I better get busy, I think I just heard that new visitor calling my name…”CHOMP!”

For more on VLB, check these websites:  http://ohioline.osu.edu/sc195/013.html, http://www.hort.cornell.edu/vlb/html   

 Posted by Mark Bir

Our Monthly Theme

April is all about earth care in Hershey Children’s Garden. Our programming emphasis centers around helping young children identify their common connection with and respect for other living things. We are offering stories like The Lorax by Dr. Seuss as an opportunity to discover that we are a part of the same planet.

Today, we hosted our first Nature Tales Story Time under the tree house. The leaves emerging from winter sleep and a gentle warm breeze moving daffodils in full bloom provided the perfect setting for over thirty participants listening to a story and creating flowers with their hand prints. Come next Wednesday at 11 a.m. to hear another story and learn about what we could do with our "garbage" besides through it away.

There are many things you could do at home with your little one to help them connect to their world. One idea would be to plant a pollinator garden, butterfly and bee friendly, and draw pictures of what comes to visit the flowers. The Garden has a number of examples of plant material just right for such a project. We are happy to show you what plants you can plant in your Cleveland yard. Another idea would to go for a walk through Hershey Children’s Garden or a park. See if you can find examples of the food chain taking place (a bee visiting a flower, a rabbit eating grass) and draw a picture of it. Whatever you decide to do with your child, encourage them to talk about what they are seeing and doing, what is around them. Show them how you are caring for the earth.
 

Count Down To Open

One week. That is all there is to the opening of the 11th season in the Hershey Children’s Garden. Are you looking forward to it? I know I am. Each year monthly themes are chosen upon which to base programs. We firmly believe in the power of play and story to impact a child’s development, so we are taking a literary approach this season. We are highlighting a different children’s story each month and incorporating it into our programs.

First of all, April is dedicated to earth care and cultivating a respect for all life. We want to demonstrate that our lives and actions are interconnected with the rest of life on earth. The Lorax by Dr. Seuss carries this message well. We wil bring the story to life through several programs.

BotaniCool^®School for Little Buds (ages 3-5 yrs) 
Saturdays, April 17 and May 15

Bring your little buds to the Garden and watch them bloom! In this series, children ages 3-5 will use the Garden to learn about caring for the Earth. Registration is available for individual sessions or the series. Please register in advance.

Plant a Truffula Tree            
Sundays, April 4, 11, 18 & 25
Saturdays, April 10, 17 & 24

Posted by Josh Steffen 

Celebrate Earth Day and Arbor Day with nature crafts for children showcasing the importance of trees.

No registration required.

Date: Saturday and Sunday, April 24 & 25, 2010; 1:00-4:00pm