Weber Basin pilots Tacoma 31 hybrid Bermuda lawns after BYU tests show major drought tolerance

The Weber Basin Water Conservancy District has begun a residential pilot installing Tacoma 31 triploid hybrid Bermuda grass to test whether the variety can reduce summer irrigation for Utah homeowners, district staff and researchers said at a Utah Division of Water Resources webinar.

The pilot will convert 18 homes — about 61,000 square feet total — from cool‑season turf to the warm‑season Tacoma 31 and track metered water use, maintenance and homeowner perceptions. "We're hoping for at least a 50% savings when we're done," David (water conservation manager, Weber Basin Water Conservancy District) said, adding that even a smaller reduction would be significant for district planning.

Why it matters: Utah water agencies fund lawn‑removal rebates but still need attractive, lower‑water landscape options in neighborhoods where grass is desirable. Presenters said triploid hybrid Bermuda, which has inert seed and shorter stolon internodes, offers a potential middle ground: green‑space and cooling benefits with far lower irrigation needs than Kentucky bluegrass.

BYU field research and drought tolerance

Ashley, a graduate researcher who studied hybrid Bermudas at BYU and is now at Purdue, summarized randomized plot trials comparing hybrid Bermudas (including Tacoma 31 and Latitude 36) with Kentucky bluegrass across three irrigation regimes. The team measured NDVI (a greenness index), visual quality ratings, percent cover and soil moisture.

"A hybrid Bermuda grass could go 5 to 9 weeks without irrigation before it shows stress," Ashley said, describing 2023 and 2024 trials. In one 2024 span the research plots went from July 30 to Oct. 14 — 76 days — without irrigation in sandy test plots and still maintained near‑optimal greenness in some hybrid plots. Researchers cautioned that soil type and microclimate affect outcomes and that the lower limits of recommended irrigation need more study.

Trait comparisons and management notes

Panelists emphasized differences in growth and maintenance: Tacoma 31 generally requires less nitrogen (about 3 pounds per 1,000 square feet per season versus roughly 4 pounds for Kentucky bluegrass), less mowing and about 50% lower irrigation demand in the trials. It also produces more thatch and has a longer spring dormancy — it typically greens up later in the spring because of cooler soil temperatures. Ashley noted shade performance requires higher soil temperatures, but in several northern Utah sites the grass performed adequately with about six hours of sun.

Installation approaches discussed included sod and sprigging. David said the district initially overwatered some new installs during establishment, then trimmed back to a once‑a‑week schedule and saw good establishment. Eric, a grower on the webinar, described homeowner watering at his property as "about once every 10 days" currently, while recommending about a half‑inch once weekly in midsummer for many residential settings.

Weber Basin pilot design and homeowner experience

Weber Basin's pilot aims to preserve each household's existing sprinkler setup to allow a direct historical meter comparison rather than optimizing irrigation systems up front. Contractors removed existing turf and installed Tacoma 31 (one crew for removal, one for installation), and homeowners agreed to allow submeter monitoring and to answer surveys on perception and maintenance.

Early homeowner feedback has been positive, David said: residents who initially worried about brown squares after installation often reported satisfaction within a week as the turf established. The district will combine visual timelapse, meter records and surveys to produce a preliminary assessment later this year and continue a full calendar year for a more complete data set.

Tradeoffs and open questions

Panelists flagged tradeoffs: winter dormancy timing (longer in cooler areas), potential need for targeted early‑spring weed control while warm‑season turf is dormant, and more thatch management. They reiterated that common (seeded) Bermuda remains illegal in Utah; triploid hybrid varieties have inert seed and were delisted from the state noxious‑weed restrictions after studies showed they were not more aggressive than Kentucky bluegrass.

Next steps

Weber Basin plans to publish pilot findings after combining metered water use, maintenance logs and homeowner surveys; the division will post the webinar recording and follow‑up resources. Presenters encouraged homeowners to consult local extension offices and the Division's rebate guidance at slowflow.org before changing landscapes.

Quotes used in this story are from webinar presenters Ashley (BYU/Purdue researcher), Eric (marketing director, Chair Farm), David (Weber Basin Water Conservancy District) and host Candace Shively (Utah Division of Water Resources).