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: greenstreet@mindspring.com

Tuesday, August 23, 2011

An outstanding ash tree!

Here's an incredible ash tree that I stumbled upon today. It's well over a hundred years old, in perfect health, and with thin leaflets that give the plant a texture more like that of willow than ash. It's Fraxinus angustifolia, colloquially called frêne à feuilles étroites (which translates as narrow-leaved ash).

What I have yet to mention is the fact that I found this tree at the Jardin des Plantes in Paris, France. I met one of the horticulturalists and told him about emerald ash borer in Les Etats-Unis. He told me about some pest that is killing all the horsechestnuts in Paris.

At the same garden is this beautiful allee of London plane trees. Contrast this with the hodgepodge of species that are thrown together in the streets of Ann Arbor so as to avoid another catastrophe such as Dutch elm disease.

I suggest a compromise. Go ahead and use a single species on one block or on one street. Just don't make use of a single species for more than a certain small percent of the overall urban forest. There is nothing more strikingly beautiful than streets such as Cherokee and Harbrook where a single species is utilized (kentucky coffeetree and ginkgo respectively).

And here's one photo of the very extensive display gardens at the Jardin des Plantes. Ooh-la-la.

Thursday, August 18, 2011

A prickly not-an-ash

Prickly-ash as an ornamental plant? Well, yeah, why not? Especially if you can put it full sun, like the large hedge/clone I encountered south of Ypsilanti yesterday.

In case you aren't familiar with it, prickly-ash is not an ash. It's a native clonal shrub, and it is a bit prickly. Without any striking features (usually), it gets passed by without notice, but chances are you've brushed against it on occasion. 

Now that your attention has been inescapably grabbed by those opening remarks, here's some really cool things about it. It's one of those subtropical things that sent a emissary up north to test out our cold winters. Taste the fruit. It's a lime! Now spit out the fruit because you're going to be salivating heavily for the next 30 minutes while your mouth goes to sleep. Now look down at that drool on your t-shirt. What a mess. Now wipe up the drool.

Another feature: the leaves provide food for the larvae of the great swallowtail butterfly, a beautiful insect as a winged adult (but looking identical to bird dropping as a larva).

So let's hear it for this scratch-and-sniff underdog. (Yeah.) Compound leaves, alternately arranged with the occasional set of weak prickles along the midrib; reddish hairy buds; all parts (especially the fruit) with an aromatic citrus-y aroma and taste; clonal suckering habit. Zanthoxylum americanum in the literature. It is one of just a couple native representatives of the interesting and important Rutaceae family. Speaking of which . . . I need the herb Ruta graveolens (rue) for my garden, but I never see it at the markets. It is the national plant of Lithuania, where they sing songs about it and place it on the desks of judges to ward off witches and evil spirits. If you run into it, let me know. (Thank you Laura for coming through on this for me!).





Monday, August 15, 2011

Weed number 7 and the also-rans

Photo by Ronald Calhoun (copyright!)
Deciding which were the worst six weeds in my garden was a no-brainer. After thinking it over for a week, I decided that there is only one other weed species that deserves special recognition. And after consulting a helpful authority, I found out its identity: nimbleweed (Muhlenbergia schreberi) a native grass with underground rhizomes that break off when you pull up the stems. The rhizomes produce new stems, making eradication very difficult.

The other garden weeds I consider also-rans. In my more intensively managed beds, there is  lambquarters, black nightshade and a bit of plantain (Plantago spp.). In the less-managed shrub borders, I struggle with two species of Cardamine, motherwort, celandine (Chelidonium majus) with the orange sap, and foxtails (Setaria). In shady edges, Impatiens pallida is abundant.

Corydalis incisa (photo by Arrowhead Alpines)
And then there are my mistakes. I thought the cute little cranesbill (Geranium (robertianum?)) growing along East Delhi might make a nice addition to my garden. Now it is competing against garlic mustard.  When Corydalis incisa didn't thrive in my rock garden, I assumed it must be a finicky plant. Wrong! You can purchase this species from Arrowhead Alpines, but be forewarned. And the alliums . . I pull them out by the hank.

And let's not forget the woodies which went unmentioned in my last post: common buckthorn, redbud (I've heard several complaints about this plant from others this season), poison-ivy, etc.

Here's an off-the-cuff top-10 list of worst weeds submitted to me by Tony Reznicek of the University of Michigan Herbarium:
1. Oxalis sp. (O. stricta, O. dillenii, and even O. corniculata)
2. Digitaria sanguinalis (hairy crabgrass)
3. Conyza canadensis (horseweed)
4. Erigeron annuus (annual fleabane)
5. Setaria sp (foxtail grass)
6. Medicago lupulina (black medic)
7. Shrub seedlings (Lonicera sp., Rhamnus sp.)
8. Tree seedlings (Quercus sp., Juglans nigra, Cercis canadensis especially)
9. Solidago sp.(goldenrods, especially S. altissima)
10. Taraxacum officinale (dandelion, mostly in my paths)

Friday, August 12, 2011

A west-side garden

Today I stumbled upon a remarkable back yard garden at an address on W Huron. The focal point was a massive butterfly-bush (Buddleia) that worked like a sci-fi tractor-beam on butterflies and hummingbirds. A lot of birds followed just to see what the commotion was.

A powerful sweet fragrance came from Clethra alnifolia, a shrub that was very au courant a decade ago, but didn't end up as amenable to cultivation as we all hoped. I had forgotten about. It comes from New Jersey. So do I. I wonder what is behind that coincidence? I tried Clethra it in my garden once and it didn't last a week. "Give me rich, moist soil, damn you", it called out minutes before it expired.

What the heck is this bizarre plant with the turtle-head flowers and goth foliage?

(Tony Reznicek answers:  "Acanthus, probably A. spinosus. It might pass on in a really severe winter, but other species are quite hardy.")

In front of the house was a very happy oregon grape-holly (Mahonia/Berberis), an evergreen barberry relative which I deeply wish I could grow. Maybe I'll excavate the parent soil at my house and then order a glacier to carve our some depressions and leave behind a nice till soil. These plants are everywhere in the Pacific Northwest where they are native.

(Tony Reznicek comments: "The lovely Mahonia appears to be one of the Japanese species, M. bealii or M. japonica -- also marginal in hardiness, but doable in a sheltered site in town -- not one of the west coast species.")
Great foliage on this viburnum, don't cha think? Someone please save me a search and e-mail its name.

My, how the streets are changing

Remember not long ago when streets were lined with green ash trees, one after another? And before that, American elms? How different things are today. I hardly even know what some of these new trees are. Consider this one block of Bunker Hill, for example.

2045: swamp white oak (Quercus bicolor)
2429: sweetgum (Liquidambar styraciflua) -- good!
2438: American elm (Ulmus americana) -- bold move!
2450: Asian fringetree (Chionanthus retusus) -- wow!
2453: hardy rubbertree (Eucommia ulmoides) -- gosh!
2464: silver basswood (Tilia tomentosa) -- a gem within the genus
2514: Maackia amurensis (across street) -- wow squared!
2570: Hackberry (Celtis occidentalis) -- long overdue

And there's a tupelo (Nyssa) in the yard of 2477, a prolifically fruiting hornbeam (Carpinus) in another, and a hophornbeam (Ostyra), yellowwood (Cladrastis) and English oak (Quercus robur) around the corner on Bluett. Kudos to Kay Sicheneder and others at the city for broadening the palette.

Thursday, August 11, 2011

Sophora in the summer

Sophora is used extensively as a street tree in Ann Arbor, but almost never in the private landscape. With its soft fluffy clouds of light yellow flowers, for mid-summer action it can't be beat. (I should have posted this a week or two ago because right right now the flowers are beginning to drop.)

Sophora japonica is the name I learned. I call is sophora. Simple enough. But its proper scientific name is now Styphnolobium japonica. And it doesn't come from Japan. But no doubt that is, as my daughter might say, TMI*.  The tree is a legume. It has green twigs and pinnately compound leaves. Check it out on Melrose off Devonshire, or Geddes east of Washtenaw, or along Brooks (where it grows with corktree) and Fountain St.

There's a relative of this tree that grows in the southwest. I know this because a certain local professional botanist grows it in Ann Arbor. He gave me a sample of the fruit to see if I could identify the genus. I should have been able to guess but I was too intimidated to be think clearly. Westerners call the plant 'Eve's necklace' because of the way the pod is constricted between the 'peas.' Necklace-y for sure. And just like the fruit of the trees growing along Melrose, Geddes and Brooks.

*TMI -- 'too much information.'
A little more TMI: some 'common' names of sophora are 'pagoda tree' and 'scholar tree.'

Monday, August 8, 2011

The 10 most worst weeds in my garden

These aren't just the worst. These are the most worst. Chime in, add your two cents, and let the other dozen readers of this blog know how you would rate them.

1) Oxalis: If I were granted the wish to eliminate for all time one garden weed from my garden, it would be Oxalis.  But if the djinni were to ask, 'which one?' I'm afraid I would be stumped. Both Oxalis stricta and O. dillenii are (apparently) native to North America, and it's hard to tell them apart. Michigan flora tells me that the former tends to have a single stem, whereas the latter is more branchy (my word). Anyway they are both ubiquitous weeds, and their exploding capsules reliably propel seed into every nook and cranny of the garden. These plants have the common name of 'yellow wood-sorrel,' and they can be mixed with salad greens to add a lemony spice.

2) Three-seeded mercury: you've probably never heard those three words in that sequence before. How about Acalypha virginica? Hey, I didn't say this would be easy. I admit that my choice of this spurge-relative may be controversial, but in sheer numbers, it runs a close second to Oxalis; and in volume it is number one in my garden. I used an old botanical reference to key out the identity of this species. I was unable to make out the flower parts; luckily the floral key accommodated the observation "flower parts indistinguishable." To the plant's credit: it's very easy to pull out. Also noted: it's another native.

3) Black medick (Medicago lupulina): with it's clover-like leaves and yellow flowers, this weed is probably familiar to anyone who gardens. You have to grab the stem right at its base to get the roots out. If you're in clay more drastic measures might be required. And the base of the plant always seems to hide behind or amidst the stems of those things you want to keep.

4) Hairy crabgrass (Digitaria sanguinalis): ignore the garden for a week, and the crabgrass plants will reach 10" across when you return.

5) Virginia creeper (Parthenocissus quinquefolia): presumably it was the wet spring that enabled the thousands of virginia creeper seeds to germinate in my garden. Even without the new seedlings, this vine is hard enough to keep out of the flower beds. This spring also brought an amazing number of oak and hickory seedlings. The oaks were easy to pull up. I'm afraid I'll never be rid of the hickories.

6) Asian bittersweet (Celastrus orbiculata): I'm giving this one a prominent place in my top ten list because it is the scariest. I've seen woodlands destroyed by this nuisance. It has a solid foothold in my neighborhood, and the birds are continually defecating its seed into my garden. Bad birds. There's no doubt about its identity when you pull out those reddish roots.

7) What? 10:00 pm already?!! Help me pick the final four!

Tuesday, August 2, 2011

When goats go bad . . .

. . . they eat the bark off your finest garden specimens, in this case a beautiful upright 'Persian ironwood' (Parrotia persica).  Seriously, if you want a nice garden, don't keeps goats, and especially don't give them free reign as my family and I did. (In fact a couple times we came home and found them camped out on the living room couch, where they rested while digesting their generous meal of succulent house plants.)

But here's something I was surprised to see: the goats ate the bark all the way around, but the tree didn't die.  The first year it produced new bark, sent sprouts up from the base, and the crown remained full and deep green. 

the trunk in year 2
Year two, the new bark has developed impressively. Unfortunately the crown is very thin, and I can't predict if I'll have to cut the tree back to its sprouts.

My understanding: the goats didn't touch the water-conducting xylem, so the roots were able to supply the crown with water. However, the goats did eat the outer phloem which conducts photosynthates to the roots. Basically the roots have been starved. I'm leaving the basal sprouts in hopes that the low foliage will help the roots recover.  

Monday, August 1, 2011

A banana plant grows in Dexter

Musa basjoo is its name, and although it's not the edible banana of commerce, it's darn close. When the homeowners first planted it, they made sure to apply a thick bed of mulch before the onset of winter. Now they don't even bother -- it's perfectly content tucked into a south-west-facing corner of the house where it receives full sun year-round.

By the end of the summer, the leaves extend well above the roof line. I don't believe it has ever flowered -- it would need a longer growing season than that of Michigan.