After a long winter dormancy homeowners look forward to their lawns greening up again as a sign that spring has arrived. But exactly when does grass start growing again each year?
The timing of renewed grass growth depends on several factors. Temperature, location and grass species all play a role in determining when those green blades will emerge again.
Understanding the keys to spring green-up can help homeowners know when to expect their lawns to bounce back and what care may be needed.
Why Grass Goes Dormant in Winter
Before looking at spring green-up, it helps to understand why grass dies back in winter.
Cool-season grasses like fescue bluegrass and ryegrass naturally go dormant as temperatures drop and daylight hours decrease in fall and winter. Growth slows and then stops as grass enters a period of dormancy.
The grass essentially hibernates through winter. The green color fades as moisture and nutrients retreat to the roots and crown.
While the blades die back, the root system remains alive but inactive until warmer temperatures return. Dormancy is the grass’s survival mechanism for getting through harsh winter conditions.
What Triggers Grass to Grow Again in Spring?
As the weather warms 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:
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
So in most regions, it is a combination of warmer soil and increasing daylight that signals the grass to start emerging from dormancy in spring.
How to Know When Soil Is Warm Enough
You can use a soil thermometer to directly check if your lawn’s soil has reached 55°F. But an easier method is tracking air temperatures.
There is a close correlation between air and soil temperatures. When daytime highs reach about 55°F or higher consistently, you can assume the soil has also warmed to the point that grass growth will resume.
The Role of Location and Grass Species
When your grass comes out of dormancy each spring will vary depending on two factors:
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Geographic location – Warmer regions will reach the threshold soil temperatures 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 the onset of spring greens up will happen earlier for a cool-season grass like tall fescue in Georgia than it will for bermudagrass in Minnesota based on climate and species differences.
Typical Timeline for Spring Green-Up
While local weather plays a role year to year, the general timeline for renewed spring growth is:
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Late February to Early March – Transition zone and southern lawns with warm-season grass start to emerge from dormancy as soil temps reach 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 exceed 55°F.
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Late March to Mid April – Cool-season lawns in the northern half of the U.S. have sufficiently warm soils for grass to come out of dormancy.
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Late April to Early May – In the coldest northern regions, lawn green-up typically occurs during this period as soils finally warm after a long winter.
These timeframes can vary by several weeks depending on the weather patterns each spring. Unusually warm years may see earlier green-up, while prolonged cool springs delay the process.
The Green-Up Process and Spring Lawn Care
The transition back to active growth in spring happens gradually. Here’s what to expect as your lawn comes out of dormancy:
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Light green – The first signs of spring green-up are light green patches as the new blades begin emerging.
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Slow growth – Initially the grass grows very slowly even once dormancy has broken. Growth rate increases as soil temperatures continue to rise.
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Full green – Within 4-6 weeks of first green-up, the lawn will be fully green and actively growing at its normal pace.
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Mowing – Wait until the grass has filled in and reached a height of about 3-4 inches before mowing in spring.
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Fertilizer – Cool-season grasses can be fertilized 4-6 weeks after green-up; warm-season grass 6-8 weeks after.
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Weed control – Pre-emergent weed control should be applied in early spring right before the soil temperatures reach about 55°F in your area.
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Overseeding – For cool-season lawns, the best time to overseed bare spots is late summer/early fall when temperatures start dropping again.
Understanding the spring green-up process allows you to plan lawn care appropriately as your grass comes back to life.
Why Grass May Not Green Up Normally in Spring
In some cases, lawns are slow to revive or don’t turn fully green in spring. Reasons include:
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Excessive thatch buildup preventing growth through the layer of undecomposed organic matter.
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Low soil temperatures due to excessive shade, poor drainage or high clay content.
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Compacted soil limiting root development.
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Heavy damage from pests or disease the previous year.
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Insufficient watering preventing the grass from coming out of dormancy.
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Very alkaline or acidic soil pH preventing nutrient availability.
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Excessive use of de-icing salts in winter causing soil toxicity issues.
Addressing those underlying issues can help get your lawn growing healthily again in spring.
Be Patient Waiting for Green-Up
It’s exciting to see your lawn return to its vibrant green color, signaling that spring has arrived. But be patient, as full green-up takes some time.
Even once temperatures are warm enough to trigger growth, it takes a while for the grass to fill in completely. Avoid the temptation to overfertilize or excessively water to force faster spring greening.
With proper soil preparation and fall fertilization, your lawn will bounce back beautifully on its own timeline as soil temperatures rise. Give your grass time to gradually and fully transition out of winter dormancy.
Before you know it, consistent soil temperatures above 55°F will have your cool-season lawn lush and green again, signaling the start of another beautiful spring.
When Does The Grass Green Up & Start Growing Again?
FAQ
What months does grass grow the most?
At what temperature does grass start growing again?
Does grass grow back after winter?
Will grass grow back in spring?
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 back?
However, some are grown as annuals in colder climates and will only last for one growing season. Assuming you have a perennial ornamental grass, the timing of when it will grow back depends on whether it’s a cool or warm season grass.
When does warm season grass grow?
Warm-season grasses, typically found in USDA hardiness zones 7-10, start growing rapidly when the soil temperature climbs above 70°F. The warm temperatures and seasonal rains keep the soil hydrated and facilitate growth.
When does grass grow?
If you have a warm season grass, you’ll likely see growth starting in late spring or early summer. It’s important to note that warm-season grasses turn shades of brown as the weather turns colder, and once they turn brown, they can be trimmed back at almost any time.