It is important to schedule lawn care maintenance during times that match the life cycle of the turfgrass.
Minnesota lawns of cool season turfgrasses bear the stress of changing weather and can survive harsh winters. Cool season turf grass growth cycle
These grasses endure throughout the seasons because they grow rapidly during spring and fall when temperatures are cool and then become inactive during the heat and drought of summer.
As a homeowner, seeing your lawn transition from dull brown to vibrant green is one of the most exciting signs that spring has arrived. But when exactly does all this green growth begin? The timing of renewed grass growth depends on several key factors.
Why Grass Goes Dormant in Winter
Before we look at spring revival, it helps to understand why lawn grass dies back over winter in the first place. Cool-season grasses like fescue, bluegrass and ryegrass naturally go dormant as temperatures drop and daylight hours decrease in fall and winter. Growth slowly shuts down as the grass enters a period of dormancy or hibernation to survive harsh conditions.
The green color fades as moisture and nutrients recede down to the roots and crown. The blades die back, but the root system remains alive, though inactive, until warmer weather returns. This dormancy is the grass plant’s survival mechanism for making it through freezing temperatures and diminished sunlight.
What Triggers Growth in Spring
As conditions improve in spring, the grass plants are triggered to come out of dormancy and resume active growth. There are two main factors that stimulate this transition
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Soil Temperature – Grass requires soil temperatures above 55°F for the roots to uptake nutrients and water needed for growth Consistent soils temps of 55°F or higher are the signal for the grass to break dormancy.
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Day Length – The increasing daylight hours as the days lengthen in spring also triggers grass plants to initiate new growth,
So in most regions, it’s the combination of warmer soil and longer days that prompts the grass to emerge from its dormant state as spring begins.
Tracking Soil Temperature
You can directly check your lawn’s soil temperature with a soil thermometer. But an easier method is monitoring air temperatures. There is a close correlation between air and soil temperatures. When daytime highs reach and hold at around 55°F or higher consistently, you can assume the soil has also warmed to 55°F, the point where grass growth resumes.
Regional and Species Differences
Exactly when your lawn comes out of winter dormancy will vary depending on:
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Geographic location – Warmer southern regions will hit the 55°F soil threshold earlier than cooler northern areas. Expect lawns in the south and west to green up sooner.
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Grass species – Warm-season grasses like bermuda, zoysia and centipede need temperatures closer to 65°F before spring growth resumes, later than cool-season types.
So green-up will happen earlier for a cool-season grass like tall fescue in Georgia than bermudagrass in Minnesota based on climate and species differences.
Typical Timeline
While local weather patterns play a role year-to-year, the general timeline for spring green-up is:
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Late February to Early March – Transition zone and southern lawns with warm-season grasses begin to emerge from dormancy as soil temps approach 65°F.
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Mid to Late March – Cool-season lawns in the south and transition zone fully resume growth as soil temps consistently top 55°F.
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Late March to Mid April – Cool-season lawns in the northern half of the U.S. also have warm enough soils for grass plants to come out of dormancy.
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Late April to Early May – In the coldest northern tier, green-up typically occurs during this period when soils finally begin warming after winter.
These timeframes can shift earlier or later by several weeks depending on spring weather patterns each year.
The Green-Up Process
The transition back to active growth in spring happens slowly. Here’s what to expect as your lawn comes out of dormancy:
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First, light green patches emerge as new blades begin growing.
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Initially, the grass grows very slowly even once dormancy has broken. The growth rate increases as soil temps continue rising.
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Within 4-6 weeks of initial green-up, the lawn will be fully green and growing at its normal pace.
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Wait until the grass fills in and reaches 3-4 inches tall before mowing in spring.
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Cool-season grasses can be fertilized 4-6 weeks after green-up, warm-season varieties 6-8 weeks after.
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Pre-emergent weed control should be applied in early spring before soil temperatures reach 55°F.
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For cool-season lawns, the optimal time to overseed bare spots is late summer/early fall when temperatures start dropping again.
Why Grass May Not Green Up
Sometimes lawns are slow to revive in spring or never turn completely green. Common causes include:
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Thick thatch layer preventing growth through the matted debris.
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Low soil temperatures from excessive shade, poor drainage or high clay content.
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Compacted soil limiting root development.
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Significant previous damage from pests or disease.
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Insufficient irrigation preventing the grass from breaking dormancy.
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Extreme soil pH preventing nutrient availability.
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Winter deicing salt buildup causing soil toxicity.
Addressing those underlying issues can help get your lawn growing healthily again.
Be Patient
Seeing your lawn transition from dreary brown back to lush green is an exciting confirmation that spring has sprung. But be patient, as full green-up takes some time.
Even once temperatures are ideal, it takes a while for the lawn to fill in completely. Avoid pushing growth with excessive fertilizer or water. With proper fall preparation, your grass will revive beautifully on its own timeline as soil warms.
Before you know it, consistent soil temperatures above 55°F will have your cool-season lawn green again, signaling another spring is here!
Seasonal plant growth cycle
In early spring, roots are long and full of nutrients stored from the fall. Shoots, the part of grass visible above ground, use this stored energy for growth.
In warm summer temperatures, leaf and root growth slow down. Plants rest during times of heat and drought. Roots can be damaged when soil temperatures are above 85°F.
In the fall months shoots start to grow again and nutrients are stored in the long roots for the winter. Optimal shoot growth occurs with air temperatures of 55 to 75°F.
Cool-season root growth is stimulated by soil temperatures above 32°F, and is optimal with soil temperatures between 50 and 65°F.
When to schedule lawn maintenance
It is important to schedule your lawn care maintenance during times that match the life cycle of the turfgrass.
- Do not add fertilizer too early in the spring. This may encourage the grass to grow during a time when it should be slow or dormant.
- Do not spray to control weeds when temperatures are warm. This increases the likelihood of damaging the lawn.
- Do not fertilize in hot mid-summer months. This can cause irreversible damage to your lawn.
- Crabgrass doesnt develop until late spring or early summer, so dont apply herbicide used to prevent pre-emerging crabgrass in the fall.
See Water-saving strategies for home lawns for information on how and when to water.
When Does Grass Start Growing Again For Spring
FAQ
What month does the grass start growing?
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Soil Temperature is Key:Grass growth is primarily driven by soil temperature, not just air temperature.
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Warm-Season Grasses:Warm-season grasses like Bermuda grass and Zoysia grass begin to emerge from dormancy when soil temperatures reach above 50°F.
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Cool-Season Grasses:Cool-season grasses like Kentucky bluegrass and fescue thrive when soil temperatures are consistently above 50°F.
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Los Angeles Specifics:Due to the mild winters in Los Angeles, some grass may continue to grow throughout the winter, but significant growth typically picks up in the spring.
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Late March/Early April:You might see some early signs of growth in late March or early April, but the most noticeable growth occurs as the weather warms up and the days grow longer.
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Mowing:You’ll likely need to start mowing your lawn again around mid to late April, depending on the weather and type of grass you have.
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Planting Grass Seed:If you’re planting grass seed, Pennington Seed recommends planting in late spring or early summer for warm-season grasses, or in fall for cool-season grasses.
At what temperature does grass start to grow again?
When the total heat degrees reaches 200, soil is warm enough for grass to grow. This usually occurs in February.Feb 9, 2016
When should grass start sprouting?
Whether you’re repairing bare spots, overseeding an existing lawn or starting from scratch, you can generally expect grass seedlings to emerge within seven to 21 days when grown under proper conditions. It may take another three to four weeks of growth before grass is long enough to mow.
What triggers grass to grow in spring?
Daylight. Grass can only grow when it has sunlight and carbon dioxide to trigger photosynthesis. Both cool- and warm-season grasses grow more with more …Mar 21, 2022
When should grass grow again?
When spring rolls around, your grass should start growing again once soil conditions become favorable for its species. Generally, that means when temperatures rise above 50°F. Since 50°F is low for most species, the growth will not be speedy at this time.
When does grass stop growing?
Grass generally stops growing in fall or winter when the peak daytime temperature drops below 50°F. Warm-season grasses often grow between 80-95°F. Some species, like the Zoysia grass and Bermuda grass, can range from 64-110°F. These varieties of grass may stop growing at slightly higher temperatures than the above rule, such as 55°F.
When does grass grow most?
The most vigorous grass growth occurs in late spring as temperatures climb and more sunlight fuels growth. Lawn experts consider May the peak of spring grass growth in most northern regions. Grass growth slows a bit in early summer as temperatures rise and soil moisture decreases.
Why does grass grow so fast in spring?
There are two main factors that stimulate this transition: Soil Temperature – Grass needs soil temperatures above 55°F for root uptake and growth. Consistent soil temps at or above 55°F break dormancy. Day Length – Increasing daylight as the days grow longer in spring also triggers grass plants to start growing
Why did grass grow back in August?
August marked the end of peak growing season for warm-season grasses. Cooler fall temperatures allowed northern grasses to bounce back. September nighttime temperatures below 60°F slowed warm-season grasses’ growth. But cool-season grasses relished the cooler fall days and grew vigorously again.
When does Grass Grow Green?
Possible green-up during warm spells. Growth increases as days lengthen and temperatures rise above 40°F. Grass Growth accelerates with spring’s arrival.