Winter is not yet officially here, but we have a few harbingers at hand now. Perhaps traffic patterns are ruined by ice and snow, but patterns on plants of that same snow and ice are far more felicitous. Enjoy the well-named Robert Frostian dust of snow on the hemlock tree, the thought of snowdrop flowers to come in perhaps another month, the river birch catkins patterned against blue or even slate gray clouds as the tree reaches skyward.
Name That Plant winner
Now, let’s reveal the most recent Name That Plant contest and the first and only plant lover with the correct identification.
The picture for the contest was of the rarely-seen-by-the-uninitiated early spring vermilion flowers of katsuratree, Cercidiphyllum japonicum. Most people are attracted to its springtime rosy-tinged leaves, with those leaves maturing to blue-green in summer and finally apricot to yellow fall foliage hues. Further, when they fall, with just the right magical mixture of moisture and secret natural seasonings, a crème brulee or burnt sugar aroma emerges as a natural delight.
Our winner was a bit of a ringer, professional horticulturist that he is — Curt Van Blarcum, the Director of Grounds at the Western Reserve Academy in Hudson. He indeed uses katsuratrees in his designs on campus, and we have discussed their beauty a number of times, including different variants, including weeping katsuratree.
I love the explanatory nature of the genus name Cercidiphllum, with “Cercis” (the genus for redbuds) and “phylum” which comes from the Latin/Greek, meaning “leaf.” The leaves of katsuratrees have somewhat heart-shaped redbud-like leaves. Plant one or more next spring.
New plant name contest
The last contest was a bit difficult, so, let us make this one even more difficult. Actually, this time we will not rely on reader’s botanical acumen, but rather their sense of whimsy and silliness. That is a clue.
This week, we combine two of my pastimes, walking in the woods and identifying various organisms on logs and trees. For example, I love the fungus amongus growing on logs. One day earlier this year, while walking at Johnson Woods Nature Preserve near Orrville, I espied a hole in a log and something seemingly growing in it or on that log. Can you identify this globular organism?
Your prize if you are the first correct e-mailer (chatfield.1@osu.edu) or texter (330-466-0270), will be either a mushroom identification book, an Ohio State University Fruit Tree guide, or Aldo Leopold’s famous conservation classic, A Sand County Almanac.
Why host ranges matter
And now for something entirely different. Last week, my Extension compatriots Pam Bennett, Joe Boggs, Erik Draper and I educated and were educated by our audience with a six-hour workshop at the Ohio Turfgrass Foundation’s annual convention in Columbus.
Our focus was on landscaping, ever remembering Alex Cusnow and his bon mot of “The lawn is the canvas on which the rest of the landscape is painted.” We painted and painted, concluding with a discussion of the host ranges of pests and pathogens of trees and shrubs.
Of what were we speaking? Well, it is important for landscape managers to know how widespread a particular problem might be. The emerald ash borer insect and the Dutch elm disease fungal pathogen are very bad things, but at least they only occur on ash (Fraxinus) and elm (Ulmus) respectively. On the other hand, Asian longhorned beetle insects and the Botrytis gray mold fungus occur on dozens of different plants. So entomologists with their insects and plant pathologists with their plant pathogenic fungi and bacteria and other pathogens, talk often about host ranges. What is the host range of plum curculio insects or of the plum black knot fungus?
You can readily see why this matters. If you diagnose plum black knot on your plum tree will it threaten your peach trees, or even your apple trees? That is why host range information is handy. As it turns out, plum black knot only occurs on plants in the genus Prunus. What are some of the species in the Prunus genus? Prunus persica is peach, P. cerasifera is purpleleaf plum, P. serotina is wild black cherry, P. armeniaca is apricot.
All are susceptible to the plum black knot pathogen, Dibotryon morbosum (what a name). Apple trees, on the other hand, are not susceptible to plum black knot as they are different enough genetically to be in a different genus, Malus. They are not part of the host range of Dibotryon morbosum.
Will powdery mildew of rose spread (caused by the fungus Sphaerotheca pannosa) to phlox? No on two counts. First, powdery mildew of rose is not caused by the same fungus that causes a powdery mildew disease on phlox. That phlox powdery mildew fungus is Erisyphe cichoracearum, which in its own stead infects phlox, but not roses.
Second, and this is often misrepresented, but is biologically important: Plant diseases do not spread. Say what? Think about it; the pathogen spreads, by wind or water or in soil or by insect vectors, but disease is more than just the pathogen. Plant disease is a process that involves three necessary factors, one is a virulent pathogen, but the other two are a susceptible host plant, and an environment conducive to disease such as high relative humidity in the case of many powdery mildew diseases.
So, on and on we went. Host ranges are useful to nurserymen and nurserywomen, landscape architects and designers, landscape installers and maintenance companies, Master Gardener volunteers and all plant lovers. Which crab apples are susceptible to apple scab disease, which roses are susceptible to black spot disease, and what are some of those trees susceptible to the Asian longhorned beetle, such as maples — and heaven forbid — buckeyes?
Personally, despite this challenge, despite the spartan challenge of many buckeye pests, I am confident they will prevail.
Let us close with an Aldo Leopold quote:
“The last word in ignorance is the man who says of an animal or plant, “What good is it?” If the land mechanism as a whole is good, then every part is good, whether we understand it or not. If the biota, in the course of aeons, has built something we like but do not understand, then who but a fool would discard seemingly useless parts? To keep every cog and wheel is the first precaution of intelligent tinkering.”
Jim Chatfield is a horticultural educator with Ohio State University Extension. If you have questions about caring for your garden, write: Jim Chatfield, Plant Lovers’ Almanac, Ohio State University Extension, 1680 Madison Ave., Wooster, OH 44691. Send email to chatfield.1@cfaes.osu.edu or call 330-466-0270. Please include your phone number if you write.