Strange Weather! Roller Coaster Spring, Bentgrass Off-Color, Poa Seedheads and an Award
It was supposed to be a dry and normal spring. Instead, it has been a strange spring. If you are a grower, April and May haven’t been easy months. A few reasons: It has been cool: A lack of warmth has been an underlying issue all spring — just ask a golf course superintendent. Creeping bentgrass remains mostly off-color and it currently has that “On again, off again” strange purplish hue which is most pronounced on sand-based putting greens. Nighttime temperatures have remained cooler than bentgrass likes (dipping below 50 degrees). It has been dry: Dry conditions this spring have also been impactful. By mid-May the USDA drought monitor had begun to map “abnormally dry” and even “moderate drought” in central and northern Illinois. That’s about a month earlier than usual. Our wettest month in Illinois is usually May and so that’s strange. It has been windy: Evapotranspiration rates have been at record high levels this spring. And a dust storm on May 16, 2025 caught us off-guard in Illinois and the last time a dust storm was recorded in Chicago was May 31, 1985. We were told the sheer magnitude of the latest one matched the 1930s or the dust bowl years — before nearly all of us were born. Now that’s really strange.
In the landscape we are seeing good recovery of thin lawn areas which were seeded. Supplemental irrigation was likely needed during mid-May to avoid drought. Spirea is now in peak bloom and Vanhoutte spirea, a long standing favorite, is currently loaded with white blooms. And in the roadsides, black locust trees and Morrow’s honeysuckle shrubs are both with white flowers. And in golf’s rough areas seedheads of fescue have begun to appear — a good thing. The inflorescence of fine fescues provide an additional aesthetic element that will develop and remain all year in unmown out-of-play areas. And then there’s Poa or annual bluegrass. It has quietly been enjoying life from tee to green this cool spring. Our first flush of Poa annua whitish seedheads has begun. Enjoy Memorial Day weekend like Poa! Don’t forget a light jacket — a cool forecast is on tap (60s for highs).
Weather
Scouting for Abiotic Injury — Drought Stress
Drought is something that we track each year. In intensively managed settings (putting greens) soil moisture is monitored daily with soil moisture meters. We often scout areas which are prone to midday wilt stress.
Turfgrass drought stress is affected by
- Turfgrass species —Relative drought resistance*, avoidance and tolerance of commonly used turfgrass species is known. Comparatively fescues used in the Midwest are more resistant to drought stress.
- VERY GOOD overall — Tall fescue, fine fescue
- GOOD overall — Kentucky bluegrass
- FAIR overall — Creeping bentgrass, perennial ryegrass
- POOR overall — Annual bluegrass
*Reference — Jack Fry, Bingru Huang. 2004. Applied Turfgrass Science and Physiology. See table 3–2, page 74.
Other factors associated with drought stress
- Soil type — native sandy soils or sand-based root zones are most prone to drought stress
- Soil compaction — a common cause of shallow roots
- Objects buried — a barrier (large rocks etc.) will physically prevent normal root growth
- Preemergent herbicides — improper application can inhibit normal root growth (always read the label and follow manufacture’s instructions)
Recent drought stress examples
Scouting for Abiotic Injury — Anthocyanin Pigments are Colorful?
We are continuing to see creeping bentgrass look off-color due to cool temperatures at night. Physiologically speaking, it isn’t happy . And this would be the spring for that!
Conditions conducive for cool season turfgrass growth
- Optimum temperatures for shoot growth — between 64 and 74 °F for cool season turf
- Optimum temperatures for root growth — between 50 and 64 °F for cool season turf
The spring season favors maximum growth of both shoots and roots of cool season turfgrasses. However, a lack of snow cover (a dry winter) meant winter desiccation was a concern and in fact did occur. A dry spring, along with cool conditions, in 2025 likely added fuel to that fire. This helps explain why creeping bentgrass (greens) continues to remain off-color all of May. But this patchy coloring of turfgrass is abiotic. And that means it’s not disease. And that’s a good thing.
False spring, false colors: What does purple turf mean? Part 1
In 2021, a nice article on turfgrass pigments was written by Dr. Dominic Patrella, Assistant Professor of Managed Turfgrass Systems, University of Minnesota. Read full article here
“In spring and fall, turfgrass leaves often change colors, similar to how the leaves of deciduous trees turn colors in the fall, most often turning a shade of purple or red. The degree to which leaves turn purple is related to the turfgrass species and even the specific cultivar: some species turn purple more easily than others and even some cultivars of the same species may or not turn purple. On golf course putting greens, tees, and fairways, brown/red patches can occur randomly over the surface due to genetic segregation of the species present (creeping bentgrass [Agrostis stolonifera] especially; Figure 1). Usually, the changing colors don’t signal that something bad is occurring, but it is a sign of plants responding to changing environmental conditions.”
Education & Communication by CDGA’s Green Committee
More information
- The USGA Water Conservation Playbook — The USGA Water Conservation Playbook details a range of strategies that will help golf courses optimize their irrigation and use less water when it is possible or necessary. These strategies fit a range of budgets and water conservation goals, with something of value for golf courses in every environment.
- GCSAA BMPs (Best Management Practices) — In 2017, GCSAA engaged in an initiative to establish golf course best management practices (BMPs) in all 50 states by the end of 2020. As of Dec. 31, 2020, each of the 50 states had established state specific BMPs featuring agronomic practices that support environmental stewardship. In 2024, Ontario published the first BMPs for Canadian provinces.
Early Career Award
Shehbaz Singh will receive the Early Career Award in the area of Industry and Consulting. The American Society for Horticulture Science (ASHS) offers Early Career Awards each year by reviewing nominations of scientists. Awards are given to one person in each of the following fields: Teaching, Research, Extension, or Industry/Consulting.
Shehbaz will accept his award this summer at the annual meeting of the ASHS in New Orleans. Congratulations!
Final Photo
“Fringe tree grows as either a wide-spreading, multi-stemmed shrub or a small tree. Useful in native woodland gardens, as a specimen plant, in groups, borders, or near large buildings. The fringe tree’s most outstanding feature is the fragrant, strap-like, white flowers that are borne in 6 to 8 inch long fleecy panicles in late May to early June.” see Morton Arboretum
