Research Theme: Water

Background

Persistent drought and heat in recent years have increased pressure on lawn irrigation practices across Minnesota. To better understand how common irrigation technologies perform under real conditions, our group began evaluating rain sensors, soil moisture sensors, and weather‑based controllers at the Minnesota Landscape Arboretum. During summer 2024, we monitored 24 individually controlled research plots equipped with flow meters to measure water use over a 15‑week period. By comparing plots managed with rain sensors, in‑ground soil sensors, and handheld moisture readings, we aimed to quantify how effectively each technology reduces unnecessary irrigation. This work provides a clearer picture of how irrigation decisions and water savings can vary across sensor types, offering practical insights for homeowners and cities working to improve outdoor water efficiency.

Research questions

• How much water can be saved by using technology such as a rain sensor or soil sensor in an irrigation system?
• Do soil sensors save more water than rain sensors?
• How much water would be saved if the 100 square foot blocks represented a large yard (10,890 sq.ft)?

Practical implications

This research will help identify which technologies save the most water under real Minnesota weather patterns and how reliably they prevent irrigation when soil moisture is already sufficient. The findings will be useful for homeowners, cities, and irrigation professionals by clarifying the conditions where rain sensors fall short, where soil sensors excel, and how these tools can be installed and managed for maximum impact. Ultimately, this work supports more informed decisions about upgrading or maintaining irrigation systems to reduce water use across Minnesota landscapes.

Background

Years of turfgrass research show that some species and mixtures perform far better than others under drought, shade, disease pressure, and other stresses. During dry Minnesota summers, many homeowners struggle to maintain lawns, especially when relying on Kentucky bluegrass, a popular but relatively drought‑sensitive species. These challenges are intensified in parts of the Twin Cities with sandy soils that hold little moisture and require more frequent watering. Using drought‑tolerant mixtures can significantly reduce water use while maintaining lawn quality, but residents lack clear, accessible guidance on which mixtures to choose.

To address this gap, we are launching a coordinated, multi‑year effort at four Twin Cities sites to develop data‑driven seed‑mixture recommendations. By evaluating mixtures grown without supplemental irrigation, we aim to identify combinations that stay healthy, conserve water, and can be adopted by homeowners and municipalities.

Research questions

• Which turfgrass mixtures provide the greatest drought tolerance under Minnesota conditions without supplemental irrigation?
• How do different species mixtures compare in establishment, resilience, and long‑term performance on varying soil types, including sandy soils common in the Twin Cities?
• What seed mixtures can be recommended to homeowners and cities to reduce outdoor water use while maintaining lawn quality? 

Practical implications

This work will help identify drought‑tolerant mixtures that balance appearance, durability, and water efficiency across different soil types and site conditions. The results will give homeowners, cities, and seed retailers clearer guidance on mixtures that perform well under stress, reducing the guesswork that often comes with choosing grass seed. Ultimately, we aim to develop data‑driven seed‑mix recommendations that will make it easier for Minnesotans to install lawns that use less water, withstand extreme weather, and remain resilient over time.

Background

To expand water‑conservation efforts beyond individual households, we partnered with two homeowner associations (HOAs) to assess and improve irrigation practices across large, community‑managed turf areas. The project uses a structured process beginning with discussions to identify challenges, followed by irrigation assessments of each zone, zone mapping, and identification of areas prone to water waste. These evaluations informed tailored recommendations that helped each HOA adopt best watering practices and reduce unnecessary irrigation. A designated community contact completed lawn management training and served as a point person for communication and ongoing adjustments.

Research questions

• How much water can be saved when community‑managed irrigation systems are audited, adjusted, and paired with best watering practices?
• Which irrigation improvements provide the greatest impact on reducing water waste across large turf areas?
• How effectively can trained community contacts support long‑term irrigation efficiency through monitoring, communication, and seasonal adjustments? 

Practical implications

We hope to better understand how community‑managed properties can reduce unnecessary irrigation by improving system design, scheduling, and on‑site oversight. This work highlights where large turf areas typically lose water—through misaligned sprinkler heads, outdated controllers, unnoticed leaks, or schedules that continue running despite rainfall. By pairing system audits with best watering practices and training a designated community contact, homeowner associations gain the knowledge and structure needed to manage irrigation more effectively over time.

Background

The Diffusion Network Project, or “Lawn Leader” program, trains Master Gardener Volunteers to learn and share best lawn management practices and water‑saving strategies within their communities. Participants complete online modules featuring videos, demonstrations, and hands‑on activities designed to build practical skills they can confidently teach to neighbors. After in‑person training, volunteers host neighborhood events during the summer, selecting two to three topics—at least one focused on reducing lawn irrigation—to share with their neighbors.

The program continues to expand across the Twin Cities, pairing education with a broader effort to measure how lawn‑care knowledge spreads. To assess this, thousands of initial and follow‑up lawn‑care knowledge surveys were distributed across multiple metro communities. These data help evaluate baseline understanding, track changes over time, and determine how effectively Lawn Leader events contribute to knowledge diffusion across the region.

Research questions

• How effectively can trained community volunteers increase neighborhood knowledge of best lawn management and water‑saving practices?
• Which teaching approaches or demonstration activities are most successful at helping residents adopt practices that reduce lawn irrigation?
• How far and how quickly does lawn‑care knowledge spread within and beyond neighborhoods after Lawn Leader events?

Practical implications

We hope to better understand how trained community volunteers can help spread best lawn management practices and water‑saving strategies across neighborhoods. By equipping Master Gardener Volunteers with clear demonstrations, hands‑on activities, and focused messaging, the program strengthens their ability to teach practical skills that improve lawn performance while reducing irrigation needs. Neighborhood events create opportunities for residents to learn directly from trusted peers, making information more accessible and relevant to local conditions.

The ongoing knowledge‑assessment surveys help measure how lawn‑care understanding changes over time and how effectively information moves through communities. These insights will guide future training, refine outreach materials, and support broader efforts to reduce outdoor water use across the Twin Cities. Ultimately, the program aims to build a network of informed residents who can confidently share water‑efficient practices and contribute to long‑term landscape sustainability.