This site is for people who like plants -- growers, enthusiasts, aesthetes, novices and professionals, those who appreciate wild things and those who appreciate the cultivated. I garden in Chelsea, and I've been visiting people's yards for 20+ years in the course of my work. My goal is to make this blog a community project, so if you share my interests, please consider becoming a participant and contributing content -- Guerin. Info:

Sunday, October 4, 2015

A true American chestnut

note old staminate flowers still attached
When I was a young lad growing up in New Jersey, there were still a few big chestnut trees in the neighborhood. When we kids took the “long” unaccompanied one-mile trek to Finnerty’s candy store, we would take a shortcut through a neighbor's yard with a huge specimen chestnut tree. We took great pains to circumvent passing underneath its crown which was littered with big round stiff and prickly burs. But we always stopped to pick one up -- it felt like the spines could easily draw blood.

That tree died, as did almost every other one of the estimated four billion chestnut trees that made up 25% of the great ‘Chestnut-Oak’ forests east of the Mississippi. But for years afterwards, in the Smokey Mountains and elsewhere, you could regularly find sprouts that had shot up from the still-vital roots from where there had once been a forest tree. Unfortunately the sprouts never amounted to much. They certainly never grew large enough to set fruit before they were once again attacked by the introduced pathogenic fungus Cryphonectria parasitica. My understanding is that it is becoming quite rare to find chestnut sprouts any longer.

Once in a while you will run into a healthy specimen in somebody’s yard. These trees were grown from saplings distributed by various state agencies in an attempt to re-establish the species (or at least remind people of their dendrological heritage). I found one on N Whitman Circle in Loch Alpine this morning.

I think of the chestnut tree as being a kind of beech tree on steroids. The leaves of chestnuts are much larger that those of beech, and rather than a little spiny beech-nut husk, you get a formidable hedge-hog of a fruit.

There is no relation between the true chestnut (Castanea dentata) and the common horse-chestnut (Aesculus hippocastananum). The latter is related to the buckeye, and bears palmately-compound leaves and inedible (if you are not a rodent or goat) fruit. Chestnuts are related to oaks. Horse-chestnuts are more closely related (botanically) to the maple. 

Sunday, August 23, 2015

Out with the Old, In with the Pinky Winky

Other than the oak-leaf, Pinky Winky is my first hydrangea. (No, that's not exactly true: I remember killing an Hydrangea paniculata tar diva years ago. Apparently it requires water.)

So why Pinky Winky? I saw it at my brother's place in southeast Maine. Not only was it it lovely, not only was it flowering at a time when most other things had packed it up for the season, it was so full of pollinators that you could hear the buzz from inside the house. So listen closely to the video I took with my cell phone.

What else is new? How about this one from Detroit's Eastern Market: a bougainvillea! If anybody out there has ideas about how to keep this over the winter, please clue me in. I expect I'll bring it inside, place it in front of a bright window, and attend to all the fallen leaves before family members tell me I have to toss it out.

And here are some plants I have decided to retire: Saruma henryi, an upright yellow-flowered asian relative of wild ginger (Asarum canadense). (Note that the two genera names are anagrams). Saruma is fine early in the season but it gets too large and bushy and then it seeds around, and I am tired of managing it. Also going is Sinocalycanthus chinensis, an Asian relative of Carolina sweetshrub (Calycanthus floridus). It is unusual for sure, and the flowers look just like sunnyside-down fried eggs. But being unusual with eggy flowers does not cut it when space is at a premium.

But wait! Look what I dug up: one giant cyclamen bulb. That one stays for sure.

I'm thinning out my collection of jack-in-the-pulpits. Half of them I received via seed exchange, and knew nothing about them until I grew them on. There's some satisfaction in knowing that I probably have the largest collection of Arisaema's in Chelsea, Michigan, but I've got to face the fact that, while curious, they are not all garden-worthy.

Well, at least that's a small start. Anyone out there want a seedling of my hardy orange (Poncirus trifoliata)? It is beautiful, wickedly thorny, and the big parent plant didn't make it through this past winter. Plenty of offspring from where my son and I pelted each other with the sour limes.

Friday, August 21, 2015

Apricots in August

I suppose it is not generally recognized that apricots will grow quite nicely in southeast Michigan, thank you very much. They do. My tree service once had to cope with one specimen near Portage Lake whose trunk was 4' in diameter.

So I remembered passing a specimen on Fair off Burwood which I had seen laden with fruit a few years ago. I went back to check it out this month. See the photo to the left. They were good! OK, not as good as the fat cultivated Turkish apricots for which you have to empty your wallet, but . . . this tree was probably not provided a whole lot of TLC, given that the masses of fruit on the driveway had been run over repeatedly by the homeowner's car. Also the last two winters had taken their toll, much like they did on many ornamental cherry trees.

Another August event: the big native lobelia that gave me a case of syphilis when I planted it in off-site in a dry soil, Lobelia siphilitica. It is native to most Michigan counties on wet sites. Actually it did fine in my normally-dryish garden, thanks to lots of rain and fresh soil. Or maybe I am wrong about which species I am growing -- that's always a possibility.

Golden-seal (Hydrastis canadensis) is listed as having many useful herbal properties, but my guess is that the original herbalists were mostly impressed by its "knotty yellow rhizomes"* and assumed the plants had higher powers. It is native to southern Michigan. I grow it. It spreads. It makes a couple nice "raspberries." They don't taste good. I think I will make room for something better next year. says the plant has become rare in the wild due to intense harvesting by evil herbalists. 

(* -- I quote

This one on the right flowered back in July, but I don't want to forget to write about it. It is a huge-flowered evening primrose, Oenothera macrocarpa (= O. missouriensis). They were selling them for a buck a pop at the farmer's market in Ann Arbor so I splurged and bought five. Quite a show when they were at their peak. A lovely color. The plant is also called both Missouri evening-primrose and Ozark sundrop. What is the difference between a sundrop and an evening primrose? To my knowledge, none, except the sundrops flower in the sun, and the other ones . . you get the idea. This one, I don't know, it was always in flower when I got home in the late afternoon.

Today's comic relief comes in the form of the thousands of Japanese beetles that I found feasting and making insect nookie on the grape vines next to the parking lot at the Chelsea High School. You usually find them in great numbers next to golf courses and other places with extensive lawns. Lindens are a favorite food.

Friday, July 31, 2015

Surprising Appearance of a Chinese Yellowhorn

Nobody could figure out what it is.

images courtesy Steve Goebel Jr
A small tree growing across the street from the Jefferson Market in Ann Arbor. Bill Dale, a tree worker employed by the City of Ann Arbor, spotted it and brought a sample back to the office. He and co-worker Steve Goebel Jr were completely flummoxed, and asked for help from the community of "tree professionals" like me. Alternately-arranged pinnately-compound leaves, huge 'tropical' fruit with very large seeds. I had no idea. In the next couple of days, people suggested a wide range of possibilities until certified arborist Isaac Finn Dunigan of Grand Rapids came up with "Chinese yellowhorn."

In my world, finding a completely unrecognizable novel woody plant growing in a public space is so rare that it, like, never happens. But there it was cataloged in Michael Dirr's fantastic Manual of Woody Landscape Plants: Xanthoceras sorbifolium.

"Striking tree or more often large shrub, virtually unknown in commerce and gardens, zones 5-8, introduced via the Plant Select program at Colorado State University." Roasted seeds reportedly taste a little like macadamia nuts. In the mostly tropical Sapindaceae family, which now includes maples and horse-chestnuts.

Methinks the big payoff is the flower. Never seen it, but I've got to have one. 

Image is ripped from the headlines World Wide Web. Thank you Kew Gardens.

Thursday, July 30, 2015

Avoid falling for tree and shrub pest control scams

The following article was released by Michigan State Extension this week. It is the result of a complaint from a certain tree-care worker who was getting tired of responding to calls from worried customers. The customers had been advised by a mega-lawn-care representative that their trees/shrubs had pest issues requiring multiple spray applications. Said tree-care worker had to drive around town, checking the trees, and assuring the customers that there was no issue.
Posted on July 28, 2015 by David Smitley, Michigan State University Extension, Department of Entomology

It looks like we are seeing a new pesticide treatment sales scam. Most of the complaints so far are from Michigan’s Ann Arbor-Ypsilanti area, although everyone should be alert for this scam that involves a scare tactic about a non-existent or unimportant pest.

It works like this: A sales representative from a lawn, tree and shrub care company visits your yard and fills out a report. On the report, spider mites or another pest is circled and a warning is hand-written, “Spider mites are damaging your trees. A miticide treatment is highly recommended.”

The reason a scam is suspected is because one arborist in the Ann Arbor, Michigan, area has had six of his customers call him after they received this warning. When he investigated, he could not find any spider mites or damage at any of the six locations. Sometimes the sales person will leave a little Zip-lock bag with the report, like they did at my house about 15 years ago. It contained a leaf with a hole in it, and the warning, “You have gypsy moth. A spray is highly recommended.” When I looked at my trees, I had a difficult time finding any leaves with holes in them, and when I did, it was caused by a cankerworm, not gypsy moth.

A few holes in tree leaves are completely harmless. In fact, a pesticide spray would probably cause more harm than good because it will disrupt the predators and parasites providing natural control. We don’t usually see problems with spider mites in the yard and garden unless an insecticide, like carbaryl, is being sprayed. Carbaryl and some other insecticides can kill the predators that usually keep spider mites under control, but spider mites may be resistant to the insecticide and thrive in the absence of predators.

Arborists and responsible landscapers dread hearing about this type of scam because it makes their industry look bad. This is very unfair to a landscaping and tree care industry consisting of 99.5 percent responsible business owners. In fact, the last time we had this type of scam, the local branch manager of the company promoting the scam said it was due to a “rogue employee” that had not completed training and was going against their company policy. In my opinion, if a sales representative finds 10 customers in one neighborhood that have spider mite damage, the manager should investigate to see if this is a real or imaginary problem.

If you are looking for real spider mite problems, read “Pests in Gardens and Landscapes: Spider Mites” from UC Davis, and see the attached pictures.

Spider mite damage in roses. Photo by UC Statewide IPM Project

Wednesday, July 29, 2015

Why it is generally a bad idea to put gravel in the bottom of a pot and how that relates to evolutionary biology

Even experts will sometimes advise putting a layer of gravel in the bottom of a plant pot: "for drainage." What you get in reality is a smaller pot. Think about it: if a soil is saturated such that it can hold no more water, it doesn't matter whether the bottom of the medium is a bunch of rocks or a single hole, it's gonna blow. If the soil is less than fully saturated, the water molecules will stick around in the nice spongy soil, just as a moist sponge will not leak all over your kitchen counter. The gravel does nothing.

OK, I get it, lesson learned, big deal and so what?

For one, a certain percentage of healthy plants bought from the nursery will die from drought when planted out, even if "watered" regularly. To understand this, consider that the texture* of the soil of a root ball of a balled-and-burlapped plant is invariably different than the texture of the soil into which said tree is being planted.

If the soil of the root-ball is clay, and the soil into which is being planted is sand or gravel, and if you are not mindful when watering, the water will just rush through the sand and gravel, pretty much ignoring the tightly-wound ball of clay

Reverse situation: soil of b-and-b plant is sand and the soil of its new home is clay, the water will either drain right through and be absorbed by the fine clay particles. Or worse, the plant will sit in a clay-lined pool. Even given optimum moisture, the clay lining is tough for the roots of the sandy-balled plant to penetrate, and it's much easier for the roots to swirl around in the loose sand. 

So that's why you should try and match the two soil types by amending the parent soil.

But now the payoff. . . what plant on earth is adapted to germinating in one type of soil and then discovering that three feet away, in all directions, is a soil of an entirely different texture? I will submit: none. Or almost none. Because that situation does not exist in nature, and plants have never been subjected to that unlikely do-or-die evolutionary pressure. Crossing that abrupt texture barrier is just hard to do.

*texture refers to the size of the soil particles

Sunday, July 5, 2015

A Tale of Three Hedges

Hmm, what to do with an old hedgerow that has gotten out of control . . 

How about making art!

Interesting attempt here, but comically ill-advised. Only a couple of the juniper stems remain alive after a severe reduction/reshaping. Junipers need full sun, and they don't take well to even moderate trimming. Someone with very little knowledge exerted a lot of effort to accomplish something that was doomed to fail.

And then there is the blue spruce . .
Very odd choice for a low hedge, considering it strongly aspires to be a tall tree. This planting is only about five years old. To keep it low, the main leaders were recently cut off half-way ('topped'). Methinks this will suffice for a couple years, but it will soon be impossible to keep the branches from growing into the street without cutting off the green foliage and into bare wood.

This burning bush (Euonymus alata) will manage just fine after its recent haircut. Ideally one would cut back to just above the lateral buds, but sometimes down and dirty will suffice just fine.

With old shrubs and thick stems, one runs a risk that the plant will not tolerate a severe topping. The more vigorous the plant, the better chance of success. 

Monday, June 29, 2015

Four White (and One Orange) Perennials for Late June

This post was a bit difficult for me because I was unable to identify any of these white-flowered specimens without consulting the internet, my library, and my local plant expert.

To the right is a gorgeous member of the large Polygonum genus, which includes bindweeds, knotweeds, buckwheat and much more. Polygonum has a bad rap because of the so-called Mexican bamboo (P. cuspidatum) which is neither Mexican nor a bamboo. One thing it is is very robust, so much so that it is officially unwelcome in Michigan. At one time a mail-order nursery sold cultivars of the species with a special note: 'Shipping is $10.00, or we can just give the plant your address and let it grow its way to you.'

The pictured plant is Polygonum polymorphum, which forms a nice fat clump but doesn't run wild. I've run into other Polygonum types that are deserving of wider use.

Next up is Filipendula ulmaria, 'commonly' known as meadowsweet or mead-wort. Certainly it is more commonly known in Europe and western Asia where it is native. Us North Americans are more familiar with our native F. rubra, Queen of the Prairie. I found this specimen growing in the middle of a shade garden in the 'Waterhill' neighborhood of Ann Arbor. Nobody was home so I took the liberty of entering the garden to get a close view. 

OK, this one to the right is really not for the garden. It is the common crown-vetch (Securigera varia) and I found it besides the parking lot at Knights Market. The thing is: I always thought the flowers of this species were purple (or at least purple-ish). Tony Reznicek set me straight. Whites and pinks happen. 

This plant was introduced for erosion control and it certainly does a satisfactory job in that respect. The problem is it keeps spreading and is very hard to get rid of. 

I don't know what the plant to the left is. I bought it from Kathy Melmoth at the Ann Arbor Farmers Market. She has retired and I don't know how to reach her. I presume it is a Michigan native, since that was her specialty. Also it is a composite. I was unable to match it to anything in or the second volume of The Random House Book of Perennials by Phillips and Rix (a great series to have on you shelf!). So please, dear reader, help me out. Or do I have to go back to Tony Reznicek . . .

The unfortunately-named butterfly-"weed" makes for the nicest orange in the plant world, IMHO. If I recall correctly, I received the one pictured from a grower in upstate New York, and it has more yellow that the usual type. It is also flowering much earlier than the other specimens in my garden. Butterfly-weed is a species of milkweed, Asclepias tuberosa. You'll see a lot of it in the environs of Pickerel Lake. 

And for comic relief, I offer the picture to the left. Yeah, sure, some company probably sprayed an herbicide, but how sad! I'm so used to seeing these signs posted by companies treating lawns or spraying trees. Here someone has applied chemicals to kill everything -- in an effort to beautify the parking lot. Why not plant some butterfly-weed!

Sunday, June 21, 2015

Mid-June and the Serviceberries are Ripe

A great year for serviceberry fruit! My family has been enjoying them in front of the Bank of Ann Arbor on Fifth Ave, at the entrance to the Quality 16 Theaters, and most recently, thanks to a friend, in the form of a delicious pie. This friend has four trees, which have yielded enough fruit for three pies. The biggest challenge is to beat out the waxwings, robins and catbirds.

In the odd chance you are unfamiliar with this fruit, it comes from a common native small tree that grows in the understory in our oak-hickory woods. It's also become quite popular as a landscape plant. There are a handful of species in the genus (Amelanchier). Unfortunately the tree suffers from having no good common name: serviceberry, shadbush, juneberry, etc. There is a northern species that is now being cultivated for fruit production in the Traverse City area. Growers are calling is 'saskatoon.'

So what else is going on at this time of year? One thing I have noticed is the expanded use of the Asian tree lilac (Syringa reticulata) as a street tree in Ann Arbor. I think it is unfortunate. The flowers have a very pleasant spell, but they are only attractive for a very short period before the white flowers begin to turn a rotten yellow-brown. I'm not positive, but I believe this plant has spread into the woods around Nichols Arboretum. It wouldn't surprise me to see it show up more often where it might be unwelcome.

Kousa dogwood (Cornus kousa) is putting on a fabulous show (much later than our native flowering dogwood). The picture to the right shows only a small portion of the crown of the tree by my house. I am unable to get a good picture because of the intense contrast between the white flowers and the dark shade underneath. Trust me, it's fantastic. AND, I have half a dozen babies that have sprouted from seeds underneath. Let me know if you would like one.

It's only mid June but the leaves of many crabapples are already showing signs of the leaf disease called apple scab. Leaves are beginning to fall, and trees will be barren by August. If you like crabapples, the best thing to do is to plant a cultivar that is resistant to the fungus. If you are stuck with an old-fashioned cultivar, the disease can be held in check by a couple fungicide sprays when the leaves first begin to develop. My company GreenStreet Tree Care sprays a large number of them every spring. In fact, spraying to control fungal diseases on crabapples, pines and spruces makes up about 80% of our chemical interventions. 

Sunday, June 14, 2015

A Modest Geranium Goes Rogue

I probably first encountered the cute little Geranium robertianum on the shores of Lake Huron at Drummond Island. It's a small-flowered cranesbill, known 'commonly' as herb-robert. Historically it was first collected in Michigan on Mackinac Island, and then later along the shores of the Great Lakes. It is a circumpolar species, found in parts of northern North America, Europe and Asia.

. . . And then, there is was, growing in profusion along the side of the driveway at a home on E Delhi in Ann Arbor. Ignoring the fact that it appeared to be quite rambunctious, I brought one home. Now I am chasing it down the hillside with a backpack full of Roundup, and pulling out specimens hidden under the leaves of mayapple and wild ginger.

What gives? It is a plant of tremendous fecundity and it has been in Michigan for thousands of years. Why haven't I encountered it locally before?

I e-mailed Tony Reznicek of the University of Michigan Herbarium. His reply: "Well, you have the same problem that I have. I think I got my Geranium robertianum from H. E., and am pretty sure it is the European form. It is somewhat invasive for me, but not so much in woodland shade. I doubt it will be another garlic mustard.

"I should note that farther north in Michigan, Geranium robertianum appears to be a native of rich woods, presumably a different form that your plant and mine."

So that's the likely story: it may be a native species, but there are a variety of forms found in its huge range. It seems we've introduced an aggressive genotype from overseas into the local flora. And now I can't decide how aggressive I should be about eradicating it from my property. How native is it? How important is it to protect the woodlands from this "newcomer"? Is it inevitable? Does it matter? If it gets out it will change the character of my woods, but it is not at all clear that it will outcompete anything native. After all, other than Virginia creeper, mayapple and the native oaks, hickories, cherries, etc., what I gave growing in my woods consists of Asian bittersweet, garlic mustard, weedy celandine, buckthorns, autumn olive, burning bush, japanese barberry, etc. -- all things that I wish would just disappear. I'm tempted to say "Go for it, little geranium." I don't know if I can stop it. I pulled up one large clump, threw it over my shoulder, came back a week later and found that it had re-rooted itself. 

Wikipedia tells me that in the state of Washington, it is known as Stinky Bob and classified as a noxious week.

Wednesday, May 27, 2015

Shredded Umbrella in the Garden

Here's an oddity that a fellow gardener shared with me last year. It is Syneilesis aconitifolia. Commerce dictated that it be given a "common" name, thus it is presently sold under the name 'shredded umbrella plant.'

It is a woodland species in the aster/composite family and is native to China, Japan and Korea. The flowers are of no consequence, but the leaves are pretty far-out. This is the plant's first year in my garden, and I expect it will fill in and expand in just a few years.

To me, the big thrill is seeing this plant emerge in the spring. You have to get on the belly to appreciate it, but ain't it strange? More like an emerging mushroom than anything else. Spooky!


Something happened to my primroses this year. I seem to have lost Primula kisoana (generally an easy thing to cultivate) as well as all my cultivars of the revered Japanese primrose, Primula sieboldii (search this plant on google and check out all the images!).  I have to assume my losses are due to the cold winter.

But here is one primrose that is putting on a nice show right now: Primula japonica. Hard to believe I started with just a couple specimens grown from seed!
Syneilesis aconitifolia
Syneilesis aconitifolia

An Explosion of Helicopters

I doubt anyone knows how or why this happens: all the silver and red maples in the region are laden with so much fruit it is hard to pick out any leaves. How can this phenomenon be coordinated among all the trees?

One client called yesterday and asked how to spell the word ‘schizocarp.’ I had always referred to the maple fruit as samaras, but I think she was technically correct, despite what you might read in Wikipedia.  Anyway, expect big messes to clean up if you own a soft maple, followed by a very thin-looking crown until later in the season.

Now that I consider it further, both terms for the fruit are correct. It starts as a schizocarp, which then divides into two samaras. Anyway, tell me that the color of the silver maple in the photo to the right would not cause you some alarm.

Tuesday, May 12, 2015

Birdwatching people-jam in northwest Ohio

I had no idea that the pastime of birdwatching had come to this. We scheduled our early-May visit to Maggie Marsh in northwest Ohio for a Tuesday in order to avoid any weekend crowd. It was quite cool and very windy, far from an ideal day for viewing migrating song birds. No matter. The place was packed with birdwatchers. Definitely upwards of a thousand people crowding onto the boardwalk. Maybe 5 humans for every little warbler. I have to say: this is a good thing. A large population of people finely attuned and dedicated to appreciating and preserving our wonderfully diverse bird population, whose numbers superbly reflect the biological health of our planet.

Still, it was comical at times. We came across a logjam of people with truly expensive binoculars, cameras and flash accessories all viewing and documenting a solitary Tennesee warbler. It was like a fashion shoot.

At one point along our walk, I briefly spotted a bird whose identity was lost to me, and I jokingly made the off-hand comment to my partner, “Must have been a female Cape May warbler.” In short order there was crowd around us, all peering through binoculars and passing down the word that there was a female Cape May warbler.
I can’t make too much light of this. I saw a dark thrush in the dark shade in front of a dark tree, and someone commented that it was a grey-cheeked thrush. One more for my life list.

Wednesday, April 29, 2015

Three marvelous tree oddities

I passed this tree while driving down Stein Rd off Whitmore Lake Rd.  Creepiest looking apple tree I've ever seen. The resident told me that she had been informed that this was "the oldest" apple tree in Michigan by another passing forester. It's not an impossible idea: the two "bottoms" of the tree are rooted, so, if you use your imagination to fill in the large gap, you can see it once had a massive trunk.

Here's a very queer looking beech tree (Fagus sylvatica) growing in Ann Arbor west of town. It is one of a small grove of beech oddities. The person who developed the property was an avid collector of woody plants and left behind an entire box of neatly-typed notes of his acquisitions. There's an example of his notes (with address information redacted) at the bottom of this post.

I admit this one isn't quite as remarkable, but this is what my lacebark pine (Pinus bungeana) looked like this spring. What a cool tree. I saw a few others in town this spring that displayed the same marvelous shredding. Why isn't this more common in commerce? Probably because it is slow to grow and does not provide as full a screen as, say, a blue spruce. There were several comely specimens once in Nichols Arboretum. They died. I don't know why. But I'm certain they were well over 30 years old, and surely provided more usefulness than your common austrian pine or blue spruce.

Ooh, interesting fact from Wikipedia: the species is native to the mountains of China, but . . wait for it . . it has naturalized in the Sierra de la Ventana of eastern Argentina. Sounds exotic. Who wants to visit with me?
To the right: the first page in a whole box of records of woody plant acquisitions.