Oh, what wondrous weather August brings to Ohio this year.
One result is the green of summer lawns, the continuing beauty of the many types of hydrangeas, the glossy leaves of sourgum trees, the joyful riot of color of modern petunias, the purple coneflowers in bloom in gardens and ironweed and Joe Pye weed in parklands.
You can take wonderful walks all times of day with cool breezes and blue skies, though, depending upon location, some mosquito deterrence is desirable. Let us elaborate on what is happening now in the world of plants.
Petunias and begonias
The Ornamental Plant Germplasm Center is the United States Department of Agriculture’s only repository for ornamental germplasm, mostly in seed form, and it is right here in Ohio, on the Ohio State University agriculture campus in Columbus.
In addition to the hidden seed storage vaults at the germplasm center, there are truly wonderful displays of plants there, focusing on herbaceous ornamentals such as an array of begonias in the greenhouses, trials of coreopsis and other flowering plants in the beds outside the OPGC.
Adjacent to the OPGC and next to Howlett Hall of the Department of Horticulture and Crop Science in Columbus, there is a truly mind-blowing display of petunias and other flowers in containers and hanging baskets. There is everything from Littletunia Pink to Peppy Lavender from Cascadia Rim Chianti to Potunia Plus Yellow — yes, yellow petunias.
Check it out. Dr. Pablo Jourdan of OSU, the curator of OPGC (opgc.osu.edu/germplasm), is glad to schedule tours of the facilities and views of the plants, not necessarily for one person at a time, but for your garden group. The petunias alone, so enhanced by plant breeders in recent years, are worth the trip to Columbus.
Walnuts and disease
Though black walnuts (Juglans nigra) are not typically considered a landscape plant, they are certainly an important forest denizen in Ohio and the Midwest, which make thousand cankers disease of black walnut such a great concern for woodland owners, furniture and fine wood products artisans, nut growers, and all of us.
Imagine a world without walnut veneer, or — without the ultimate treat — a black walnut-studded brownie. The one-two punch of the walnut twig beetle and the Geosmithia fungal pathogen makes thousand cankers disease a major threat to black walnut throughout the country.
The insect and fungus were polite twig-killing nuisances on Arizona walnut, but are killers of black walnut, which were introduced out West and are native to states in the East, including Ohio.
I will share more about this disease in the future as the situation merits, including the fact that walnut twig beetle has been identified and trees are showing symptoms suggestive of thousand cankers disease in Butler County in southwest Ohio, where OSU Extension held a workshop last week.
For now, back to the features of this tree. Black walnuts are a medium to large tree, growing to 70 feet or taller, especially in that elusive, moist but well-drained, organic soil we all covet.
Black walnut (juglans nigra) thrives in bottomlands but also can tolerate drier upland and open sites, though it may grow more slowly in these sites. It has large compound leaves with 11-23 leaflets (there is a terminal and many pairs), almost racquet-ball-sized nuts, all of which smell woodsy and wonderful.
Black walnuts are fierce competitors in woods and yards, producing the chemical juglone in all plant parts, which is toxic to many other plants, notably tomatoes that grow within the root zone of the black walnut tree. Tomato plants wilt and die; walnut roots continue to grow and have an advantage in nutrient availability.
But, oh, that wood. As noted in the Ohio Department of Natural Resources website (ohiodnr.com): “Its beautiful fine-grained chocolate-brown heartwood is the ultimate choice for making solid wood furniture, interior trim, gunstocks, and high-quality veneer.”
Secrest continues to grow
Sept. 16 will mark three years since the “Tornado of Wooster” struck Wayne County, the Ohio Agricultural Research and Development Center of Ohio State University, and its Secrest Arboretum. It was a hard message of the power of weather for homeowners, businesses, and the research center and arboretum.
Curator Kenny Cochran at Secrest working with Joe Cochran, Paul Snyder, Jim Karcher, Roger Hamilton and many others have done wonders with new gardens and features. These include a new Children’s Garden complete with a very popular slide, to the southwest garden with hardy agaves and prickly pear cacti, to the new Ken’s Classroom garden dedicated to Kenny from OSU Extension’s Master Gardener volunteers who have donated well over $100,000 in cash and time since the tornado.
The signature White Pine Archway at Secrest was topped off by the 130 mph winds, but new pines are intertwined for a new version.
Come walk through the arch to become wedded to the Arboretum. Visit now, again in September, and every chance you can get, dawn to dusk. It will be well worth your time to experience these views of life.
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 email@example.com or call 330-466-0270. Please include your phone number if you write.