For this exercise, we will be using Bermudagrass as our turfgrass reference.
Characteristic | Description |
Type | Warm-season grass |
Growth Habit | Spreading growth via stolons and rhizomes |
Color | Medium to dark green |
Texture | Fine to medium texture |
Height | Typically maintained at 1-2 inches |
Sun Requirements | Full sun; thrives in high light conditions |
Soil Preference | Well-drained, sandy to loamy soils |
Drought Tolerance | Moderate; requires regular watering for optimal growth |
Maintenance Level | Moderate; regular mowing and fertilization needed |
Wear Tolerance | High; suitable for heavy foot traffic |
Pest Resistance | Generally resistant to common pests |
Ideal Uses | Lawns, sports fields, golf courses |
Bermudagrass is a heat loving grass that enters ideal growing conditions between 80-95°F when all other factors are ideal.*
75°F
At a consistent 75°F, Bermudagrass is experiencing temperatures at the lower end of its ideal range. While it won't be growing as vigorously as in warmer conditions, it will still maintain a healthy green color and moderate growth.
Effect
Reduced Efficiency: Physiological processes are less efficient.
Slower Nutrient Uptake: The uptake of essential nutrients from the soil also slows down, further hindering growth and development.
Limited Root Growth: Root growth is reduced, which can affect the plant's ability to access water and nutrients effectively.
Response
Slower Photosynthesis: Photosynthesis, the process by which plants produce energy, is less efficient at this temperature compared to warmer conditions.
Reduced Metabolic Rate: Overall metabolic processes within the plant slow down, leading to less vigorous growth.
Lower Water Needs: Water loss through transpiration is reduced, so the grass requires less frequent watering.
Offset
Inputs, when properly applied, will offset the increase in temperature by overcompensating in other areas.
Moderate Watering: Water as needed to keep the soil moist but not soggy. Monitor the soil moisture and adjust watering frequency accordingly.
Reduced Mowing Frequency: You may need to mow less often due to the slower growth rate.
Scalp: Removal of dormant canopy will expose soils to the suns warming effect effectively raising the temperature experienced by the plant. This practice is not advised within 4 weeks of the historical first freeze of the fall.
Monitor for Disease: While Bermudagrass is generally less susceptible to disease at this temperature, it's still important to monitor for any signs of problems.
Fertilize with Caution: If you fertilize, use a slow-release fertilizer and apply it at a lower rate than you would during peak growing season.
70°F
At a consistent 70°F, Bermudagrass growth is significantly slowed. This temperature represents a transition zone where the grass is either preparing for dormancy in the fall or slowly emerging from it in the spring.
Effect
Slower Growth Rate: The grass will exhibit a slower growth rate compared to optimal temperatures.
Reduced Green-Up: The vibrant green color may be less intense due to reduced chlorophyll production.
Lower Water Requirements: Water demand decreases as evaporation rates are lower at cooler temperatures.
Potential for Dormancy (if prolonged): If temperatures remain consistently below 75°F for an extended period, the plant may enter a state of dormancy. Partial dormancy is a possibility, depending on conditions.
Response
To preserve nutrients (aka energy) Turf Type Tall Fescue will employ the following strategies:
Reduced Photosynthetic Activity: Photosynthesis is less efficient at this temperature, limiting energy production for growth.
Minimal Nutrient Uptake: The absorption of nutrients from the soil slows down considerably.
Limited Root Growth: Root growth and activity are reduced, hindering the plant's ability to access water and nutrients.
Increased Disease Potential: While not as severe as in consistently wet conditions, the turf may be more susceptible to certain diseases at this temperature.
Offset
Inputs, when properly applied, may offset the increase in temperature by overcompensating in other areas.
Water Infrequently: Water needs are minimal. Water only when the soil begins to dry out, and avoid overwatering.
Stop or Reduce Mowing: Mow infrequently or stop altogether as growth is minimal. If you do mow, use a higher mowing height.
Hold Off on Fertilization: At this temperature, refrain from adding nitrogen. Repeatedly, nitrogen inputs within this temperature range have been shown to increase the risk of disease.
Monitor for Disease: Keep an eye out for any signs of disease, particularly fungal issues that thrive in cool, damp conditions.
Key Considerations:
Dormancy Preparation: If these temperatures persist in the fall, the Bermudagrass will likely begin to go dormant.
Spring Green-Up: If these temperatures occur in the spring, the Bermudagrass will slowly emerge from dormancy and gradually resume active growth.
Varietal Differences: Different Bermudagrass cultivars have varying levels of cold tolerance. Some may show more signs of slowed growth or dormancy at 70°F than others.
65°F
At a consistent 65°F, Bermudagrass is on the verge of dormancy. Growth is significantly reduced, and the grass is actively preparing for winter survival.
Effect:
Minimal Growth Rate: Growth is extremely slow or nearly stopped.
Fading Color: The vibrant green color fades to a pale green or yellowish hue due to reduced chlorophyll production.
Very Low Water Requirements: Water demand is minimal due to reduced transpiration and evaporation.
Dormancy Imminent: If temperatures remain at or below 65°F for an extended period, the plant will likely enter full dormancy.
Response:
To conserve energy and prepare for dormancy, Bermudagrass employs these strategies:
Reduced Photosynthetic Activity: Photosynthesis is significantly less efficient, limiting energy production.
Minimal Nutrient Uptake: Nutrient absorption from the soil is greatly reduced.
Limited Root Growth: Root growth and activity are minimal.
Increased Disease Susceptibility: The turf becomes more vulnerable to diseases, especially in damp conditions.
Offset:
Proper management practices can support the grass during this transition:
Water Sparingly: Water only when absolutely necessary to prevent the soil from completely drying out. Overwatering can be detrimental.
Cease Mowing: Mowing is generally not needed due to minimal growth.
Avoid Fertilization: Do not fertilize at this temperature, as it can increase disease risk and stress the turf.
Monitor for Disease: Be vigilant for signs of disease and take preventative measures if necessary.
Key Considerations:
Dormancy Transition: 65°F signals the transition to dormancy for Bermudagrass.
Winter Hardiness: Ensure the turf is healthy going into dormancy to maximize winter survival.
Varietal Differences: Different cultivars have varying cold tolerance. Some may exhibit dormancy signs earlier than others.
55°F
At a consistent 55°F, Bermudagrass is firmly entrenched in dormancy. The low temperatures are affecting bermudagrass lawns with the plant is essentially shutting down all non-essential functions to conserve energy and survive the cold.
Effect:
No Visible Growth: Growth is completely halted, both above and below ground.
Brown and Dormant Appearance: The grass blades are brown, tan, or a faded yellow, indicating a complete lack of chlorophyll production.
Minimal Water Needs: The plant requires very little water due to significantly reduced transpiration.
Deep Dormancy: Metabolic processes are reduced to the bare minimum for survival.
Response:
To withstand winter conditions, Bermudagrass employs these strategies:
Complete Photosynthetic Shutdown: Photosynthesis has ceased, and the plant is no longer producing energy.
Nutrient Uptake Ceased: The absorption of nutrients from the soil is effectively halted.
Minimal Root Activity: Root growth and activity are nearly non-existent.
Reduced Respiration: Respiration, the process of energy consumption, is minimized to conserve resources.
Offset:
While you can't prevent dormancy at this temperature, proper management practices can protect the turf:
Avoid Disturbance: Do not mow, aerate, or dethatch dormant turf. Avoid heavy traffic or compaction on frozen ground.
Minimal Watering: Water only if absolutely necessary to prevent the soil from completely drying out. Overwatering can suffocate roots and promote disease.
No Fertilization: Fertilizer applications are unnecessary and potentially harmful during dormancy.
Winter Protection: In regions with harsh winters, consider applying a light layer of mulch for added protection, especially for newly established lawns.
Key Considerations:
Winter Survival: Dormancy is a natural and essential survival mechanism for Bermudagrass in cold temperatures.
Spring Recovery: Once temperatures consistently rise above 65-70°F in the spring, the Bermudagrass will gradually break dormancy and resume active growth.
Varietal Differences: Different cultivars of Bermudagrass may exhibit slight variations in their dormancy response and cold tolerance.
50°F
At a consistent 50°F, Bermudagrass is well into deep dormancy. The plant has essentially shut down all growth processes and is focused solely on surviving the cold winter temperatures.
Effect:
Complete Growth Cessation: No growth is occurring, either above or below the ground.
Brown and Dormant Appearance: The grass blades are completely brown, tan, or a very faded yellow, indicating a complete lack of chlorophyll.
Minimal Water Needs: The plant requires very little water due to extremely low transpiration rates.
Maximum Hardening: The plant has undergone physiological changes to increase its cold tolerance and prevent damage from freezing temperatures.
Response:
To withstand winter conditions, Bermudagrass employs these strategies:
Complete Metabolic Shutdown: Essential processes like photosynthesis and nutrient uptake have completely ceased.
Energy Conservation: The plant relies on stored energy reserves to survive.
Cellular Changes: Cells have undergone changes to increase their resistance to freezing temperatures.
Offset:
While you cannot prevent dormancy at this temperature, you can protect the turf:
Avoid Disturbance: Do not mow, aerate, or dethatch dormant turf. Avoid heavy traffic or compaction on frozen ground.
Minimal Watering: Water only if absolutely necessary to prevent the soil from completely drying out. Overwatering can suffocate roots and promote disease.
No Fertilization: Fertilizer applications are not needed and can be harmful during dormancy.
Winter Protection: In regions with harsh winters, consider applying a light layer of mulch, especially for newly established lawns.
Key Considerations:
Winter Survival: Dormancy is crucial for Bermudagrass to survive freezing temperatures.
40°F
At a consistent 40°F, Bermudagrass is fully hardened for winter. It has entered a state of deep dormancy where all growth processes have ceased, and the plant focuses solely on survival. This temperature is well below the threshold for active growth, and the turf is experiencing potentially damaging conditions.
Why this requires maximum hardiness:
Freezing Tolerance: Dormancy allows the plant to tolerate freezing temperatures by altering its cellular structure and reducing water content within its cells. This prevents ice crystal formation that could damage cell walls and tissues.
Preservation of Energy: With photosynthesis and nutrient uptake completely halted, the plant relies on stored energy reserves to survive.
Protection from Winter Stress: Dormancy minimizes damage from winter stressors like desiccation (drying out) from cold winds and potential physical damage from snow and ice.
Bermudagrass's Response:
Complete Growth Cessation: No growth occurs above or below ground.
Brown and Dormant Appearance: The turf appears completely brown and dormant.
Frozen Water: Water within the plant tissues may freeze, but the plant's hardiness prevents significant damage.
Minimal Metabolic Activity: Metabolic processes are reduced to the bare minimum for survival.
Recommendations for Management:
Minimalist Approach: Avoid any unnecessary activity on the dormant turf. No mowing, aeration, or dethatching.
Protect from Damage: Avoid heavy traffic, especially on frozen ground, as this can damage the crowns of the plants.
Snow Mold Prevention: In areas with prolonged snow cover, be aware of the potential for snow mold development. Ensure good drainage and avoid excessive thatch buildup.
Patience is Key: The turf will remain dormant until temperatures consistently rise above 65-70°F in the spring.
Key Considerations:
Cold Hardiness: While Bermudagrass is not as cold-hardy as some cool-season grasses, it can tolerate freezing temperatures when dormant.
Microclimate Variations: Be aware that microclimates within your lawn (e.g., shaded areas, exposed slopes) may experience slightly different temperatures and require adjusted management.
Spring Recovery: With proper care and favorable spring conditions, the Bermudagrass will gradually break dormancy and regain its green color and active growth.
Low temperatures affect your bermudagrass lawn, but they aren't often the death of it.
In conclusion, understanding the temperature responses of Bermudagrass is essential for maintaining a healthy lawn throughout the year. As this heat-loving grass transitions through various temperature ranges, it exhibits distinct growth patterns and physiological changes that impact its overall health and appearance. Proper management practices tailored to each temperature zone—ranging from moderate watering and reduced mowing at warmer temperatures to minimal disturbance and careful monitoring during dormancy—are crucial for ensuring the grass not only survives but thrives. By recognizing the signs of stress and dormancy, lawn care enthusiasts can make informed decisions that promote the resilience of Bermudagrass, paving the way for a lush, vibrant lawn come springtime.
*To accurately project the effects of temperature change, water, sun/shade, soil type and structure, water availability, and traffic must be identical as these inputs by themselves or in combination can induce dormancy.
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