Fall lawn fertilizer in Colorado: when and how much
Updated October 21, 2026. Live numbers refresh hourly.
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Colorado State University's schedule gives bluegrass and ryegrass lawns about 1 lb of nitrogen per 1,000 sq ft from mid-August to mid-September and a final feeding in early October to early November while the grass is still green and at least two to three weeks before the ground freezes. Today the 0–4 inch soil around Denver, CO averages 61°F and is warming.
- Soil today
- 61°F
- +3.8°F over 7 days
Live data for Denver, CO. Check your own ZIP below for local numbers.
Our picks
Chosen from the research below and the makers' own listings. We haven't lab-tested them.
- Best for most city lawns
Scotts Turf Builder EdgeGuard Mini Broadcast Spreader (76121B)
5,000sq ft per fill (Scotts)
A small walk-behind broadcast spreader is the easiest way to put down CSU's 1 lb of nitrogen per 1,000 sq ft evenly. This one covers a typical city lot in one fill and can block one side of its pattern along drives and walks.
- Best for big lawns
EarthWay 40 lb Residential Broadcast Spreader (2600A-Plus)
40 lbHopper (EarthWay)
On larger lots, a 40 lb hopper on pneumatic tires means fewer refills, and EarthWay's side-spread control does the same job as an edge guard along beds and sidewalks.
- Best for small yards and side strips
Scotts Whirl Hand-Powered Spreader (71074B)
1,500sq ft per fill (Scotts)
For a townhouse yard or a strip along the drive, a hand-crank spreader is enough, and it doubles as an ice-melt spreader in winter, per Scotts.
Side by side
| Pick | Best for | What it is | Holds | Assembly | Warranty | Retailer link |
|---|---|---|---|---|---|---|
| Scotts Turf Builder EdgeGuard Mini Broadcast Spreader (76121B) | Most city lawns | Walk-behind broadcast spreader | Up to 5,000 sq ft of Scotts product | Fully assembled, pre-calibrated | No mechanical warranty; 1-year satisfaction refund | Check price at Scotts |
| EarthWay 40 lb Residential Broadcast Spreader (2600A-Plus) | Big lawns | Walk-behind broadcast spreader | 40 lb hopper | Required | 1-year limited | Check price at EarthWay |
| Scotts Whirl Hand-Powered Spreader (71074B) | Small yards and side strips | Hand-crank broadcast spreader | Up to 1,500 sq ft of Scotts product | – | No mechanical warranty; 1-year satisfaction refund | Check price at Scotts |
Capacities, assembly and warranty terms are from each maker's product page. A dash means the maker doesn't list it.
Scotts Turf Builder EdgeGuard Mini Broadcast Spreader (76121B)
Best for most city lawns
A small walk-behind broadcast spreader is the easiest way to put down CSU's 1 lb of nitrogen per 1,000 sq ft evenly. This one covers a typical city lot in one fill and can block one side of its pattern along drives and walks.
Why we picked it
- Scotts says a full hopper covers up to 5,000 sq ft of Scotts product, sized for small to medium lawns.
- Ships fully assembled and pre-calibrated; the setting for each Scotts product is printed on the back of the bag.
- EdgeGuard blocks the right side of the spread pattern to keep product off sidewalks, driveways and beds (Scotts).
Downsides
- No mechanical warranty. Scotts backs it with a refund within one year if you're not satisfied.
- Settings are published for Scotts products. With another brand, look for a setting for this spreader on that bag.
- Larger lawns mean refilling; see the EarthWay below.
- What it is
- Walk-behind broadcast spreader
- Holds
- Up to 5,000 sq ft of Scotts product
- Assembly
- Fully assembled, pre-calibrated
- Edge control
- EdgeGuard (blocks right side)
- Warranty
- No mechanical warranty; 1-year satisfaction refund
- Model
- Scotts 76121B
EarthWay 40 lb Residential Broadcast Spreader (2600A-Plus)
Best for big lawns
On larger lots, a 40 lb hopper on pneumatic tires means fewer refills, and EarthWay's side-spread control does the same job as an edge guard along beds and sidewalks.
Why we picked it
- 40 lb rustproof poly hopper on an epoxy-coated chassis (EarthWay).
- EVEN-SPREAD three-hole drop system and side-spread control to protect sidewalks and garden beds.
- 9-inch pneumatic tires and solid-linkage rate control; a rate-setting matrix is included.
Downsides
- It needs assembly; EarthWay posts an assembly video and manual on the product page.
- A rain cover is sold separately (EarthWay part 77001).
- 1-year limited manufacturer defect warranty.
- What it is
- Walk-behind broadcast spreader
- Holds
- 40 lb hopper
- Assembly
- Required
- Edge control
- Side-spread control
- Tires
- 9 in pneumatic
- Warranty
- 1-year limited
- Model
- EarthWay 2600A-Plus
Scotts Whirl Hand-Powered Spreader (71074B)
Best for small yards and side strips
For a townhouse yard or a strip along the drive, a hand-crank spreader is enough, and it doubles as an ice-melt spreader in winter, per Scotts.
Why we picked it
- Scotts says it holds enough product for up to 1,500 sq ft, right-sized for a small lawn.
- Adjustable arm support, and an orange dial you set from the back of the Scotts bag.
- Scotts lists feeding, seeding and ice melt as its year-round jobs.
Downsides
- Scotts says combination weed or insect products get better results from a non-hand-crank broadcast spreader.
- You have to keep a steady walking and cranking rhythm for even coverage (Scotts).
- No mechanical warranty; Scotts offers a refund within one year if you're not satisfied.
- What it is
- Hand-crank broadcast spreader
- Holds
- Up to 1,500 sq ft of Scotts product
- Warranty
- No mechanical warranty; 1-year satisfaction refund
- Model
- Scotts 71074B
The two fall rounds
CSU fact sheet 7.202 lays out the year for Colorado lawns and puts the most weight on late summer and fall. The late-summer round helps grass recover from heat and build density. The final round, made while grass is still green, supports winter color and early spring green-up without the surge of top growth that heavy spring feeding causes.
CSU's timing note is specific: make the last fall application at least two to three weeks before the ground begins to freeze in your area. On very sandy soils, don't fertilize after late September, because nitrogen can leach into groundwater over winter.
| Grass | Mid-Aug to mid-Sept | Early Oct to early Nov |
|---|---|---|
| High-maintenance bluegrass or ryegrass | 1 | 1 (optionally 2) |
| Low-maintenance bluegrass | 1 | Optional 1 |
| Turf-type tall fescue | 1 | Optional 1 |
| Fine fescue | 1/2–1 | Not required |
| Buffalograss, blue grama | Apply no N | Apply no N |
Reading soil temperature for the late round
Purdue University notes turf growth slows sharply once soil drops below about 40°F, and fertilizer shouldn't go on frozen ground. Watching the soil temperature above helps you avoid leaving the final round too late: when soil has slid into the low 40s and keeps falling, finish up.
Along the Front Range, a warm October can keep grass green well into November, while an early arctic front can freeze the top inch in late October. The live trend tells you which year you're in.
Things that change the plan
- Returning clippings can cut your nitrogen needs by about a quarter to a third, per CSU.
- If you fed late last fall, CSU says the March–April spring feeding may not be needed.
- Native buffalograss and blue grama lawns get no fall nitrogen at all.
- Core aerating in fall before the late feeding helps water and fertilizer reach roots on compacted clay.
- Water in fertilizer, and if fall turns dry, keep watering; see winter watering in Colorado.
Questions
When should I fertilize my lawn in fall in Colorado?
CSU suggests mid-August to mid-September, then a final round in early October to early November while the grass is still green and two to three weeks before the ground freezes.
Is winterizer fertilizer necessary in Colorado?
CSU lists the October–November round as standard for high-maintenance bluegrass and optional for low-maintenance bluegrass and tall fescue. Native grasses get none.
Can I fertilize after the first snow?
If the snow melts, the ground isn't frozen, and the grass is still green, a final round is usually fine. Don't spread fertilizer on frozen or snow-covered ground.
Bottom line
Feed bluegrass and ryegrass about 1 lb of nitrogen per 1,000 sq ft from mid-August to mid-September, then once more in October or early November while the grass is green and before the ground freezes (CSU). A compact broadcast spreader with an edge guard handles most Front Range lots; go bigger for large lawns and smaller for strips.
Check price at ScottsScotts Turf Builder EdgeGuard Mini Broadcast Spreader (76121B)
Sources
- Colorado State University Extension: Lawn Care Basics (7.202)
- Purdue University: Fall fertilization for home lawns
- Scotts: Turf Builder EdgeGuard Mini Broadcast Spreader (76121B) product page
- EarthWay: 40 lb Residential Broadcast Spreader (2600A-Plus) product page
- Scotts: Whirl Hand-Powered Spreader (71074B) product page
Soil temperatures: NOAA GFS model, 0–10 cm layer. Snow: NOAA and National Weather Service. See how we measure.