The concept of a planting zone provides gardeners with a fundamental tool for successful cultivation, especially concerning perennial plants. This system helps determine which plants are most likely to survive the coldest temperatures of a specific winter season. For Wichita, Kansas, knowing this hardiness rating is particularly important due to the region’s fluctuating winter weather. Selecting plants that can endure the local cold is the first step toward building a sustainable and thriving landscape in the Midwest.
The Official Hardiness Zone for Wichita
The most recent update to the United States Department of Agriculture (USDA) Plant Hardiness Zone Map, released in 2023, places Wichita, Kansas, squarely in Zone 7a. This designation means the area experiences an average annual extreme minimum temperature that falls between 0°F and 5°F. The shift to Zone 7a represents a change from the previous 2012 classification, which had Wichita primarily in the slightly colder Zone 6b. This half-zone adjustment reflects an analysis of long-term weather data, indicating a slight warming trend in the coldest winter temperatures experienced in the region.
Gardeners can now safely consider an expanded palette of perennial plants rated for Zone 7, although choosing plants hardy to Zone 6 still provides an extra margin of safety. While the official zone is 7a, the previous Zone 6b, with an average minimum of -5°F to 0°F, remains a useful reference point for selecting resilient varieties. Wichita sits on a transitional line, making it prudent to consider both the current and immediately adjacent zones when selecting landscape additions.
Understanding the Hardiness Zone System
The USDA Plant Hardiness Zone system is the standard reference used by growers to assess a plant’s ability to survive winter cold. This map is built upon a single, long-term climate statistic: the average annual extreme minimum temperature recorded over a 30-year period. The system uses an average minimum, not the lowest temperature ever recorded, which means occasional extreme cold snaps can still occur.
The entire system divides North America into 13 major zones, each representing a 10-degree Fahrenheit range in the average minimum temperature. To provide greater precision, each of these major zones is further split into two subzones, labeled ‘a’ and ‘b,’ representing a tighter 5-degree Fahrenheit band. For example, Zone 7a indicates a minimum temperature range of 0°F to 5°F, while Zone 7b signifies a range of 5°F to 10°F. This detailed classification helps gardeners choose shrubs, trees, and perennial flowers that possess cold-tolerance to survive the winter outdoors without special protection.
Planting Strategies for Wichita’s Zone
Gardeners in Wichita’s Zone 7a should prioritize selecting perennial plants rated for this zone or, for added security, those rated for Zone 6. Choosing plants with a wider cold tolerance ensures they can withstand the occasional extreme dips in temperature common in the Midwest.
Specific perennial flowers reliably hardy in this environment include various types of coneflower (Echinacea), daylilies (Hemerocallis), and hostas, which are excellent for shaded areas. For shrubs, options like certain cultivars of Japanese maple, boxwood, and juniper are robust enough to handle the winter conditions.
When planting trees, native selections like various oaks and maples are excellent choices, as they are inherently adapted to the region’s climate variability. Gardeners should also implement specific cultural practices to enhance plant survival, particularly for those on the edge of their hardiness range. Applying a thick layer of organic mulch around the base of plants in late fall helps to insulate the soil and regulate its temperature, protecting the shallow roots from extreme freezing and thawing cycles. Ensuring new plantings are well-watered going into the winter dormancy period prevents desiccation from cold, dry winds.
Addressing Wichita’s Heat and Climate Variability
While the USDA Plant Hardiness Zone focuses entirely on winter cold, Wichita’s climate presents significant summer challenges that also affect plant survival. The American Horticultural Society (AHS) Heat Zone Map addresses this aspect by quantifying the average number of “heat days” a region experiences, defined as days where the temperature exceeds 86°F. Wichita typically falls within AHS Heat Zone 7, meaning the area experiences between 60 and 90 days above this critical temperature threshold each year.
This intense summer heat requires gardeners to select plants that are not only cold-tolerant but also capable of enduring prolonged periods of high temperatures and potential drought. Furthermore, the official zone designation does not account for local microclimates or extreme weather events common to the Great Plains. Urban areas, for instance, can experience an “urban heat island” effect, making downtown spots slightly warmer than surrounding rural areas. Gardeners should also prepare for the region’s characteristic high winds and sudden weather changes, which can stress plants regardless of their hardiness rating.