Droughty weather dominates the lives of plant lovers these days, as thunder teasers rarely pan out and everything turns a little crispier by the day and week. River birch, tuliptree, lindens and hedge maple all show a smattering of yellowing leaves that then drop to the ground. Other trees, from maples to blackgums, have early fall reddening of leaves, again showing us the stress of extended hot, dry conditions.
With large trees the amount of water needed to compensate is simply not possible to provide, and if the tree is fundamentally sound, this will simply be a year of reduced annual growth and the tree will persevere. With younger trees, especially those planted within the past few years, we can do something. Where possible, provide good thorough waterings (not scattered sprinklings), for example using Gator BagsTM, in which you fill the pouches with good drinks that slowly release water to the roots.
Longer-term weather changes are also playing out this summer as the early spring and continued hot weather result for various stages of plant development occurring early.
Check out corneliancherry dogwood (Cornus mas) and its cornucopia of ornamental features. This tree/shrub has multi-season appeal with its exfoliating bark in winter, chartreuse-yellow flowers of late winter to early spring, glossy green leaves of summer and summer-into-fall fruits.
Right now, about three weeks or so earlier than normal, the cherry-like fruits of corneliancherry dogwood are starting to show their true colors. Orange to orange-red to cherry-red fruits are on the trees now, and in great abundance on most specimens. At several programs at Secrest Arboretum in the past week, a number of people have been tempted to pop one in their mouths, proclaiming that they are ripe. Au contraire, it is still way too early, unless you really have a sour tooth.
Wait until these oblong drupe fruits become a dark purple and soft before you munch. Then cornelian-?cherry fruits are great for jellies and, if you are interested in a most wonderful, ruby-colored tart yet sweet drink that is beyond compare, try a one-quarter corneliancherry dogwood juice/three-quarter apple cider cocktail. It is quite a treat, as is the overall appeal of this most excellent small landscape tree.
Longer term yet is the progression of the range of some wonderful Southern plants northward. For decades mimosas have improved their survival rates here in Northeast Ohio. First, they would sometimes survive the winter, but only at the crown (the root-stem juncture) and the roots, needing to start all above-ground growth over again each spring and thus never achieving much height. Over the warming of our years, they are surviving higher up on the stem and many have mimosas that have survived roots, crown and tops for several years and are now attaining significant height.
Southern plants thriving
The same is true of southern magnolia (Magnolia virginiana) once surviving and growing to a true tree mostly only in the Cincinnati area, then in central Ohio and Columbus, and now into Northeast Ohio, especially the hardier ‘Bracken’s Brown Beauty’ cultivar. An even newer survivor on our local scene is crape myrtle, a wonderful small tree of the south. At Secrest Arboretum, curator Kenny Cochran and now horticulturist Paul Snider have nursed along a white-flowering crape myrtle the past eight years in Wooster.
Until the last two years, it survived only at the roots and crown, and on new growth each year it flowered later than would be expected. After the past few mild winters, it is surviving on the top and now flowers at the normal time for crape myrtles, in July.
Another fine import, an herbaceous perennial, Russian sage (Perovskia atriplicifolia) is also reigning in mid-summer gardens, holding up well in the heat and providing an almost seaside feel to the season with its wispy lavender blooms buffeted by the wind. Russian sage is the herbaceous perennial for the week on our Buckeye Yard and Garden Line newsletter (http://bygl.osu.edu) and was the 1995 Perennial Plant Association’s Plant of the Year for its foliage and bloom color, as well as form. It can be used as a specimen or feature plant or it can be massed in a grouping with other plants. The bright, light, purplish-blue flowers and silver foliage provide an accent or background for other plants and are a bright attraction to the garden. The flower spikes appear in mid-July and last up until frost. They make excellent cut flowers. The foliage is silvery and thread-like and fragrant. Plants can grow up to 4 feet tall, depending upon the cultivar. It develops woody stems that are not always killed back to the ground. To keep the overall plant less leggy and more compact, cut it back to just above the crown in early spring.
Russian sage tolerates a wide array of soil types except for wet soils. It grows best in full sun; it tolerates shade but becomes quite leggy and flops. As we are seeing now, Perovskia also tolerates dry seasons and thrives in hot summer weather. ‘Little Spire’ grows 1˝ to 2 feet tall and as wide and ‘Longin’ is 3 to 4 feet tall and only 2 to three 3 feet wide. Make sure to give the species plenty of room and it is guaranteed to attract the eye in a perennial border.
That’s it for this edition of the Almanac, but enjoy or dread (in the case of Japanese beetles) some of the other plants of summer, from cardinal flower, a scarlet-red lobelia found in gardens but also local woodlands such as Johnson Woods Nature Preserve near Orrville, to the sweet-smelling linden just finishing its summery-sweet bloom period and showing its Japanese beetle bane in the form of lacey, skeletonized beetle-fed leaves. New on the scene is ‘Rising Sun’ redbud, providing cheery yellow-green new foliage that melds well with our sunny summer days.
We had a number of tours and programs at Secrest Arboretum this past week, with memorable scenes and commentary from the walkers. The best was from sustainable farmer Joe Hartzler of Wooster, reminding us that we are all part of nature’s great experiment. A quote from the Hartzler family archive: “Nature bats last.”
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 firstname.lastname@example.org or call 330-466-0270. Please include your phone number if you write.