Big Ideas
- Tennessee’s climate varies from one end of the state to another. Therefore, the ideal turf species used in each area does, too.
- Disease and insect pressure is high across the state.
- Weeds are common, but manageable.
- Weeds can be managed proactively by maintaining a healthy stand of turfgrass i.e. managing soil fertility, disease, etc.
- Soil fertility is a first-line defense against week pressure.
Discussion Points
- When are cool season or warm season grasses best used?
- How does healthy soil affect weed pressure?
- How important is it to you to have a weed-free lawn?
Facilitator Notes
- Remind participants that the local Extension office is always available for additional questions and advice.
Overview
- Soil Test Report Interpretation
- Mobile Weed Manual Demo
Instructor Materials:
- Demo Soil Report- copies for all
- (Note: this is the same report used in the agent prep video.)
- Participant Soil Reports- you can ask them to bring these in or print them for them from the SPPC site.
- Familiarize yourself with the Mobile Weed Manual website and app, and demonstrate it for the class.
Participant Handouts:
- Their own soil test results or an example
Activity Goal
- Provide interactive opportunities to work through plant ID and use Extension resources.
- Learn to interpret and utilize soil test reports.
Agent Prep Videos- not for use during class
These videos will help you prepare to facilitate this activity.
Engage
Start by passing out the demo soil test report. Ask participants to read it over. Then, ask them if anything stands out to them.
Explore and Explain
Go over the report and explain the significance of each section or lab value. Emphasize that the recommendations int he report give you OPTIONS. You don’t need to do everything listed. Oftentimes, the recommendations consist of different ways to reach the same goal.
Elaborate
Ask participants to review their own soil reports and open the floor for questions and discussion.
Demonstrate using the mobile weed manual with any time remaining.
Evaluate
Utilize the discussion points mentioned earlier as needed.
- Which turfgrass should I plant?
- Tennessee is in the transition zone, so residents can choose between warm- or cool-season grasses. In the hotter and drier areas in the west, warm-season grasses like bermudagrass and zoysiagrass are usually better suited. In northern counties and on the Cumberland Plateau, cool-season grasses like fescues, ryegrasses, and bluegrasses are often a better fit. When choosing grass, consider your county’s climate, when you want green grass, maintenance needs (like mowing, watering, and fertilizing), and environmental factors such as shade or soil type. Cool-season grasses stay green in fall and spring but may struggle in summer, while warm-season grasses green up in spring, thrive in summer, and go dormant in winter.
- Where do I purchase good seed?
- In addition to big box stores, explore options at your local producer’s co-op, lawn and garden retailers, and other entities like (but not limited to) SiteOne Landscaping, The Hogan Company, Dickens Turf and Landscape Supply. You can also visit websites for some of the major seed producers directly like Mountain View Seeds, Barenbrug, and DLF, among others. Finally, another great source to lean on for selection is the A-LIST which is a non-profit that seeks to identify sustainable turfgrass varieties to help turf managers make their selections. You can find their recommended tall fescue list here.
- When is a good time to plant turfgrass?
- Appropriate planting times will depend on the species of grass being planted, and whether the grass is being planted as seed, sod, or plugs.
- Cool-season turfgrasses (tall fescue and mixtures containing fineleaf fescues, bluegrasses and/or rye)
- Fall is the best time to plant cool-season grasses, especially from seed, as they thrive in temperatures between 60 and 75 degrees Fahrenheit. This season offers months of optimal growth conditions in both fall and spring before summer heat arrives. The ideal planting time varies across Tennessee; on the Cumberland Plateau and similar areas, planting can start as early as mid-August and continue until mid or late September. In Murfreesboro or Knoxville, the window typically runs from mid-September to mid-October, and even later in West Tennessee, depending on the weather. For spring planting, be aware that seeds may not have enough time to establish before summer. If planting in spring, sod is often a better choice for cool-season grasses.grasses)
- Warm-season turfgrasses
- The best time to plant warm-season grasses is in late spring and early summer when temperatures are between 80 and 95 degrees Fahrenheit. Planting during this period allows for the most growth before winter and benefits from more abundant rainfall compared to late summer. While sod can technically be planted almost year-round, including in winter, planting outside of the optimal temperature range can lead to issues like weed growth and damage from extreme weather. This can result in uneven growth or competition, affecting the grass’s success in establishing uniformly.
- How do I control annual weeds in turfgrass?
- Annual weeds, which complete their life cycle in one growing season, are a common issue in Tennessee lawns. Common types include crabgrass, goosegrass, annual bluegrass (Poa), and winter annual weeds like wild violet, henbit, and chickweed. The best way to fight weeds is with healthy, thick turfgrass. Practices like balanced watering, proper fertilization, correct mowing, and regular overseeding (adding fescue to fescue) help keep turfgrass strong and weed-resistant. For those using herbicides, focus on two things: applying preemergence herbicides on time and using postemergence herbicides early, while weeds are young and easier to control.
- Mobile Weed Manual
- How do I control perennial weeds in turfgrass?
- Perennial weeds, which grow back every year, can be tough to manage in Tennessee lawns. Common examples include Virginia buttonweed, dallisgrass, wild violet, and yellow and purple nutsedge. Preemergence herbicides, which prevent weed seeds from growing, aren’t as effective on these weeds since they don’t only grow from seeds. Keeping your lawn healthy and dense is important for preventing weeds. Postemergence herbicides, which kill weeds after they have sprouted, can also help, but it’s crucial to identify the weeds correctly and choose the right product, as not all herbicides work on every weed. In tall fescue lawns, heavy infestations of perennial weeds might make it more practical to completely renovate the lawn. This is because herbicides that target tough perennial weeds without damaging the grass are often expensive, need multiple applications, and can leave large bare spots that will need replanting.
- What kind of fertilizer is best and when should I put it out?
- When in doubt, do a soil test. Soil testing is the best way to determine lime and nutrient needs, especially for phosphorous, potassium, and other nutrients. The main exception is nitrogen, as recommendations for nitrogen vary based on research for specific turfgrass types. Proper nitrogen application depends on the grass species, timing, and weather conditions. Applying nitrogen at the wrong time or during extended dry periods can stress the grass and promote weeds or diseases. Slow-release nitrogen, whether organic or synthetic, helps reduce harmful effects and provides consistent growth. Fertilizer should be applied when turfgrasses are actively growing. Fertilize cool-season grasses like tall fescue in the fall and spring when temperatures are 60-75°F, and warm-season grasses like bermudagrass in the summer when temperatures are 80-95°F.
- Should I use a cover of wheat straw or similar when I seed a new area?
- Adding mulch is a common practice to protect new seeds from erosion and help retain moisture for germination. Wheat straw or hay are popular choices in Tennessee, but straw can sometimes introduce weeds and pests like fire ants. Too much straw can also block light and air, hindering seed growth. It’s best to use clean, weed-free straw when possible, applying about 50 to 100 pounds per 1,000 square feet to cover 50-75% of bare soil. Spread it evenly across the area. Other mulch options include compost, aged sawdust, and pulp fiber. Professional landscapers may use advanced methods like erosion control blankets, straw mats, or hydromulching, where a mix of seed, mulch, and water is sprayed onto the area. Hydromulching can also include fertilizers and additives to boost growth.
- Can I grow grass in shade?
- Turfgrasses have limits in shade tolerance. Some, like fineleaf fescues or select cultivars of zoysiagrass, can handle moderate shade, but most need at least 4 to 6 hours of sunlight. The type of shade also matters; structural shade from buildings is usually more restrictive than tree shade, which may allow filtered light depending on the tree’s type, age, and canopy. Consumers can try shade-tolerant blends or increase light by pruning trees. Mowing grass slightly taller can help by increasing leaf area for light absorption. However, if grass continues to thin in shaded areas, it’s likely not suitable. Grass under trees will also compete for water and nutrients, so consider alternative plants or mulch for these spots based on your desired appearance and function.
- What can I do about brown patch in my lawn?
- There are two turfgrass diseases caused by different variants of Rhizoctonia solani: brown patch and large patch. Though similar, they affect different types of grass and need different prevention and treatment methods. Brown patch targets cool-season grasses like tall fescue, while large patch infects warm-season grasses, mainly zoysiagrass, but also bermudagrass. Both diseases are more common in areas with poor drainage, excess moisture, and other stresses like scalping injury, shade, and nutrient imbalances.
- To reduce disease risk, improve cultural practices: mow properly, fertilize correctly, and manage water wisely. Focus on improving drainage, airflow, and adjusting low areas. Water in the early morning, not in the evening. Fungicides work best when used preventatively in areas with a known history of disease. Strobilurin fungicides (like azoxystrobin) are usually more effective than triazole fungicides (like propiconazole). Azoxystrobin is found in products like Scotts DiseaseEx, Heritage G, or Strobe 2L.
- For cool-season grasses like tall fescue, apply preventative fungicides in spring when nighttime temperatures are consistently above 60°F. Brown patch is most active between 70°F and 90°F. For zoysiagrass, apply preventative fungicides in fall when nighttime temperatures are below 70°F. Large patch is most active between 50°F and 70°F.
- Fungicides can be expensive. For cool-season lawns, it might be more cost-effective to manage the disease culturally and then renovate or reseed affected areas in the fall.
- Brown Patch Disease (NC State Turf Files)
- Large Patch Disease (NC State Turf Files)
- Should I overseed/interseed my lawn?
- Overseeding usually means planting cool-season grass (like ryegrass) over warm-season grass (like bermudagrass) to keep sports fields and golf courses green during cooler months. Some people do this in their lawns to have green grass year-round, but it’s generally not recommended for less-used areas as it can stress the warm-season grass and require extra maintenance and cost. Agents may get questions about overseeding from community turfgrass managers (i.e., school, city, and county sports turf and park managers). There are several resources to assist with these discussions.
- Removing overseeded perennial ryegrass from bermudagrass turf (W239): https://utia.tennessee.edu/publications/wp-content/uploads/sites/269/2023/10/W239.pdf
- Interseeding refers to adding seeds to an existing turf to maintain density, especially in cool-season grass lawns like tall fescue. This grass doesn’t spread much and can thin out in hot summers due to stress or disease, so homeowners might need to interseed in the fall to keep their lawns thick. If the lawn has severe thinning or weed problems, a full renovation may be needed.