My husband has decided to let the lawn grow tall because dog play is tearing up the lawn. He thinks that is best to keep the grass stronger. I read from multiple sources we should keep lawn 2 to 3 inches and understood that the grass spreads out as it grows if it is cut regularly. My thinking is that it is the best way to keep the bald spots filling in.
Please let me know if you have other tips for maintaining a lawn as a dog owner and how long we should let it grow.
The mowing height range for most grasses is between 1.5 and 3 inches. In general, for most lawns 2 to 2.5 inches is optimum because if you are mowing at 3 inches, your lawn may grow to 5 or 6 inches before you mow it again.
Turfgrass and other plants produce food (carbohydrates) through photosynthesis. When you mow grass leaves, you reduce the grasses’ ability to produce food. The grass senses it is low on food (carbohydrates) from photosynthesis, and it puts all its energy into producing more leaves by producing more branches with more leaves. This process is called is called “tillering.” In effect, the mowing creates the density of the grass.
The lower and more often you mow, the denser the lawn and the finer the leaf texture becomes within a grasses tolerance range. You can also remove too much leaf tissue, which we call “scalping.” If you mow below a grasss tolerance range, it will thin out and other grasses and broadleaf weeds will encroach.
For more lawn-care suggestions, check out the OSU Extension article How to grow and maintain a healthy lawn.
As a homeowner knowing when grass grows the most can help you better care for your lawn. Grass growth follows natural cycles throughout the year in response to changing seasons and weather patterns. Growth peaks during certain months, while going dormant or slowing down in others.
Understanding these seasonal patterns allows you to time important lawn maintenance practices properly. Mowing, fertilizing, aerating and overseeding do the most good when matched to the grass’s active or dormant stages. Taking advantage of peak growing periods results in a lush, green lawn.
Key Factors Influencing Grass Growth Rates
Many variables interact to influence grass growth rates throughout the year Here are some of the most important factors
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Temperature – Cool-season grasses grow best between 60-75°F. Warm-season grasses thrive at 75-90°F. Grasses decline outside their optimal temperature ranges.
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Moisture – Adequate rainfall or irrigation keeps soil moist for active grass growth. Dry soil conditions suppress growth.
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Sunlight – Grass needs full sun for photosynthesis. More hours of sunlight in spring and summer boost grass growth.
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Fertility – Applying nitrogen fertilizer supplies a growth-stimulating nutrient. Grass grows faster with adequate nitrogen
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Mowing Height – Following the 1/3 rule by cutting no more than 1/3 of grass blade length preserves growing points and sustains growth.
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Grass Type – Growth potential depends partly on grass species. Improved cultivars offer better growth ability.
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Health Issues – Disease, insect damage and weed competition divert energy from growth. Addressing problems promotes growth.
Spring Grass Growth
Spring brings a flush of vigorous grass growth across most regions. Warming soil temperatures combined with spring rains create ideal growing conditions. Cool-season grasses like tall fescue, Kentucky bluegrass and perennial ryegrass flourish in the comfortable 60-75°F temperature range.
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March – Growth takes off as days lengthen and temperatures rise above 40°F. Grass plants emerge from winter dormancy.
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April – Growth accelerates with spring’s arrival. Cool-season grasses begin peak growth period.
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May – Peak spring growing season. Grass plants rapidly produce new shoots and leaves. Growth may slow a bit late in May as temperatures climb.
Early Summer Grass Growth
Early summer heat stimulates warm-season grasses like Bermuda grass and zoysia grass. But cool-season grasses like Kentucky bluegrass slow down in June’s hotter temperatures.
- June – Warm-season grasses thrive while cool-season grasses transition into heat stress. Mowing, irrigation and fertilization sustain growth.
Mid to Late Summer Grass Growth
By mid-summer, intense heat and drought create stressful growing conditions across many regions. Warm-season grasses withstand summer stresses better than cool-season grasses.
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July – Warm-season grasses still actively growing. Cool-season grasses struggle in heat, growth declines.
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August – Warm-season grasses winding down from peak growth. Cool-season grasses remain dormant or stalled.
Fall Grass Growth
With September’s arrival, cool-season grasses revive in the cooler fall temperatures and rainfall. Growth takes off again with autumn’s ideal 60-70°F conditions.
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September – Warm-season grasses slow down as temperatures cool. Cool-season grasses bounce back and resume vigorous growth.
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October – Peak fall growth period for cool-season grasses before frost. Plants store energy in roots for winter survival.
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November – Growth winds down as days shorten and temperatures drop. Light frosts begin damaging tender grass tissues.
Winter Grass Growth
Freezing temperatures, short days, and dormant plants characterize the winter season. Frost kills any remaining green tissue, leaving lawns tan or brown.
- December-February – Little to no active growth while grass plants remain dormant. Brief warm spells may initiate some growth.
Tips for Encouraging Peak Grass Growth
You can maximize grass growth during ideal growing seasons by using proper lawn care practices:
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Fertilize in spring and fall with products ideal for your grass type.
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Water deeply when rainfall lags to prevent drought stress.
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Mow frequently at the recommended height for your grass variety.
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Control thatch buildup, disease and weeds.
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Dethatch and aerate compacted areas.
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Overseed bare patches in spring or fall.
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Adjust mowing and watering for seasonal habits.
Understanding the seasons of peak grass growth helps time lawn care practices for success. Proper care during active growth results in a greener, denser lawn all season long.
The Key Months When Grass Grows Most Actively
Here is a quick recap of the key months when different grass types experience peak growth:
- Cool-season grasses – April, May, September, October
- Warm-season grasses – June, July
Matching your lawn care regimen to these periods of maximum grass growth allows you to take full advantage of the growing seasons in your area. Your efforts will be rewarded with a lush, thriving lawn.
Frequently Asked Questions
What is the peak growing season for grass?
The peak growing season for cool-season grasses like tall fescue is spring and fall. Warm-season grasses like Bermuda grass experience peak growth in early summer.
How much does grass grow per month during peak periods?
During peak growth periods, grass may grow 2-3 inches per month. Maximum growth varies by grass type, climate, and other factors.
When do northern grasses grow most actively?
Northern cool-season grasses grow most vigorously in spring and fall when temperatures are 60-75° F. Their active growth declines during hot summers and cold winters.
Should I only fertilize grass during peak growing seasons?
It’s ideal to fertilize during peak growth periods so nutrients support rapid growth. But you may also fertilize in summer or winter as needed to address nutrient deficiencies.
What’s the optimal soil temperature for active grass growth?
A soil temperature between 55-65° F encourages the most vigorous grass growth. Growth declines when soil drops below 50° F or rises above 70° F.
Timing your lawn care practices to match grass growth cycles results in a vibrant, healthy landscape all year long. Understanding these seasonal patterns is key to maximizing your lawn care efforts.
Related content Credit: Brooke Edmunds, Oregon State University (Cropped from original)
Alec Kowalewski, Brooke Edmunds, Ruying (Wrennie) Wang | Sep 2022 | OSU Extension Catalog Peer reviewed (Gray level) Photo: OSU Turfgrass Program (Cropped from original)
Weston Miller | Mar 2022 | OSU Extension Catalog Peer reviewed (Gray level) Credit: Chris Branam (Cropped from original)
Kym Pokorny | Apr 30, 2021 | News story
Want to learn more about this topic? Explore more resources from OSU Extension:
To promote grass density and avoid fungal disease, our expert recommends mowing heights between 2 and 2.5 inches. Photo Credit: Horticulture – Adobe Stock