As I write these words, our region is emerging from a deep freeze the likes of which we haven’t experienced in over a decade. In the wee hours of January 31st, the official temperature at the Wayne County Airport dipped to -22° F, setting an all-time record low for the date. At Secrest, the weather station recorded a slightly warmer -19° which barely kept us within the confines of a “Zone 5” winter, as defined by the USDA Plant Hardiness Zone Map. As many plant lovers know, Wooster and the majority of Wayne County is currently classified as Zone 6a, meaning that in any given winter, the minimum temperature typically falls between -5° and -10° F. The most recent map, released in 2023, is based on a compilation of temperature data from 1991-2020. For lack of a crystal ball, it essentially uses the past to provide a glimpse into what the future might hold. Over the last few decades, the overall trend is that average winter lows are warmer than those experienced during most of the 20th century. However, this past winter’s record cold is a sobering reminder that the Zone Map is intended as a general guide for which plants are likely adapted to our local climate but does not account for periodic arctic aberrations. Examples are the infamous Polar Vortex of 2014 and the bone-chilling winter of 1994, which delivered record-shattering cold temperatures across the Midwest and Northeast. 
But what will January’s polar plunge mean for the plants in the arboretum—and the plants in your garden? The short answer is that we’ll have to wait and see. However, it’s a safe bet that some plants—especially young specimens or those exposed to harsh, desiccating winds—will not emerge unscathed. Varying degrees of stem dieback or bud damage may be visible on some trees and shrubs. Some perennials will not emerge. Elsewhere, certain broadleaf evergreens and conifers will exhibit conspicuous browning by late winter. An example at Secrest is the beautiful Cedrus atlantica or blue atlas cedar. While generally regarded as capable of weathering a Zone 6 winter, temperatures into the minus teens of Zone 5 (especially when coupled with significant wind) are a recipe for severe damage or death. Only so much can be done by hopeful horticulturists (i.e., careful siting and prayer) to stretch the genetic cold tolerance encoded in every plant’s genes. Winters like the one we’ve just endured help drive that message home.
Here at Secrest (and for many intrepid gardeners), assessing winter damage and deciding how to proceed is a spring tradition. It is the inevitable consequence of trialing new or untested plants to glean firsthand knowledge of their local adaptability. Conversely, tough winters often illuminate unexpected tales of garden survival. By June I will surely be extolling the virtues of an obscure borderline-hardy tree or shrub that miraculously cheated death. The insulating blanket of snow that fell prior to January’s cold snap will certainly play a factor in saving some young plants from the compost pile. Regardless of which plants disappear from the collection, we will pick up the pieces, learn, and move on.
And so, these few steps back will be followed by several steps forward—the other mandate of springtime. Thanks to some generous donations at the end of 2025, this will be a year of multiple garden improvement projects. First, the arboretum crew will finally tackle the final portion of Gayle’s Butterfly and Hummingbird Garden, still in need of rehabilitation and replanting. While the two northern sections of the garden have recently seen an influx of colorful new perennials to attract both birds and bugs, the lightly wooded southern third requires attention. After removing a handful of crowded or declining shrubs, our goal is to establish a meandering path beneath the canopy of two maturing scarlet oaks (Quercus coccinea) flanked by a bevy of shade-tolerant shrubs and perennials of value to lepidopteran larvae and hungry hummingbirds.
Another project on the docket for 2026 involves the nascent return of a comprehensive rhododendron collection to the hillside north of the John Streeter Garden Amphitheater. While a return to the glory days of Secrest’s pre-tornado rhododendron garden will take decades, I feel that if feasible no arboretum should be without a respectable display of these beautiful evergreen shrubs. Perhaps more than any other, the devil of this pursuit will be in the details. And in this case the important details lie just below the surface. Our local soils are the most significant barrier to the cultivation of most rhododendron species and varieties. Many parts of the arboretum consist of compacted silt loam which drains at a glacial pace and predisposes rhododendrons and related plants to infection by root rot fungi, decline, and death. Many of us have likely experienced this heartbreaking turn of events. Thus, the establishment of rhododendrons at Secrest must be preceded by amendment efforts that provide a layer of coarse, free-draining soil vital to the survival of these often-finicky plants.
Finally, be on the lookout for a few other pathside features to emerge over the course of the summer and fall. The details are still a bit murky, but I can say that one project will likely be of more interest to our loyal four-legged visitors. As always, if you would like to assist with these or any other arboretum needs, please don’t hesitate to contact me at veil.11@osu.edu or (330) 202-3582.
–Jason Veil, Curator veil.11@osu.edu