Winnebago County Extension outlines climate-resilient landscaping strategies for Oshkosh area

K. Lusa, an extension educator with Winnebago County Extension, presented about 30 minutes of data and practical guidance on landscaping to adapt to climate change in Oshkosh, Wisconsin.

Lusa said rising carbon dioxide and changing weather patterns have already altered growing conditions in the region and recommended local strategies—mulches, drip irrigation, native plantings, rain gardens and careful tree selection—to reduce damage from both intense rainfall and drought.

The talk summarized state and federal climate data and translated it into actions homeowners, gardeners and municipal landscapers can take. Lusa cited the state climatology office and national sources, and noted that preindustrial atmospheric carbon dioxide measured about 280 parts per million and has risen to roughly 420 ppm today. "Climate change isn't a hoax. It really costs money and really hurts us," Lusa said, noting billions of dollars in weather-related damages in recent years.

Why it matters: Lusa said average temperatures in Wisconsin have risen about 3 degrees since 1950, with the last two decades the warmest on record, and statewide precipitation up about 20 percent with greater increases in the south and south-central regions. She told listeners that plant hardiness maps have shifted; Oshkosh registered nearly zone 5a or 5b in 2023, compared with zone 4b historically, which affects which species are suitable for local plantings.

The presentation contrasted averages with variability, stressing that similar seasonal averages can hide extremes—periods of heavy rain followed by prolonged dry spells—that create stress for plants. As an example of extreme precipitation, Lusa described a recent event in which one county received 12 inches of rain in a single day.

Practical recommendations offered

- Water management: Use organic mulches to retain soil moisture and reduce evaporation; install drip irrigation where feasible. Lusa said Winnebago County received a grant to install irrigation at a demonstration site and expects it to be operational by April; she described drip systems as kits that can cost about $300.

- Lawns and mowing: Replace or reduce turf where possible, adopt low-mow grasses or sedges, and raise mower height in May, June and July (a local "May mow high" approach rather than a "No Mow May" practice). Higher mowing promotes deeper roots and greater drought tolerance.

- Plant selection and diversity: Favor native and broadly adaptable species (Lusa cited little bluestem as an example) and use multiple varieties instead of large monocultures to reduce pest and disease vulnerability.

- Heat and storm mitigation: Plant shade trees to lower temperatures near buildings, match tree species to soil types (Lusa noted local heavy clay), and diversify tree selections to reduce risk from pests and single-species failure.

- Managing large rain events: Use berms, raised beds and rain gardens planted with species tolerant of fluctuating moisture; select plants with broad moisture tolerance for berms and rain garden edges.

- Winter and frost considerations: Choose plants tolerant of wet feet and freeze-thaw cycles, use winter mulches (organic rather than rock), avoid planting evergreens immediately adjacent to heat-reflecting buildings and use temporary coverings for vulnerable specimens in dry winters.

- Pollinator support and plant lists: Lusa reviewed early-, mid- and late-season native species for pollinators, including spring ephemerals, coneflowers, milkweeds, asters, goldenrods, big and little bluestem, prairie dropseed and native shrubs such as buttonbush and elderberry. She cautioned against cultivated lupine varieties that are invasive and provide limited pollinator benefit.

Other behavior and carbon-reduction tips included avoiding two-stroke gas leaf blowers and using electric equipment where practical, leaving some leaf litter for pollinators, reducing lawn area and using slow-release fertilizers to cut runoff; Lusa said slow-release products can increase the share of fertilizer taken up by plants from about 40–60 percent to roughly 90 percent.

Actions and local implementation: Lusa said Winnebago County obtained a grant for an irrigation installation at an Extension site and encouraged residents to attend a demonstration; beyond that, the presentation focused on homeowner and landscaper practices rather than formal municipal actions.

Resources and contact: Lusa referenced a Wisconsin climate-change resource described during the talk as a "Wiki" for climate impacts and solutions and provided contact information (klusa@wisc.edu) and a QR code linking to further materials.