Lawn Care Guide for Clackamas County
Clackamas County, Oregon
Data Story
About Lawn Care in Clackamas County, Oregon
Healthy Lawns in Clackamas County
With a lawn difficulty score of 40.9, Clackamas County is an easier place to grow grass than much of the state. The temperate Hardiness Zone 8b environment allows for a long growing season with relatively low maintenance stress.
High Rainfall Shapes Mowing Habits
The county averages 61.1 inches of rain annually, well above the state average of 37.4 inches. While this reduces watering needs, 2,074 growing degree days and only 11 heat days mean grass grows consistently, requiring frequent mowing during the peak season.
Manage Drainage in Wet Conditions
Local soil data is limited, but the high annual precipitation suggests that proper drainage is your primary concern. You may need to aerate your lawn annually to prevent soil compaction and waterlogging during the heavy rainy season.
Preparing for Seasonal Dryness
The county experienced 29 weeks in drought last year, and currently, the entire area is considered abnormally dry. Focus on building deep root systems in the spring so your lawn can survive the low-precipitation summer months.
Seeding Opportunities Start in March
Tall Fescues are excellent for this region because they handle both the winter wet and summer dry periods. With the last spring frost typically occurring on March 27, you can start your lawn projects earlier than many other Oregon residents.
Lawn Difficulty Score
Recommended Grasses
Bermudagrass
Cynodon dactylon
Climate Snapshot
Annual Precip
61.1"
Growing Degree Days
2,074.375
Base 50F
Last Spring Frost
03/27
First Fall Frost
11/14
Days Above 95F
11
Hardiness Zone
8b
Seeding Calendar — Zone 8B
Seasonal Lawn Care Checklist
Spring
- Apply pre-emergent herbicide when soil reaches 55F
- Begin mowing when grass reaches 3 inches
- Start irrigation if rainfall is below 1 inch/week
- Soil test every 2-3 years — adjust lime or sulfur as needed
Summer
- Raise mowing height to reduce heat stress
- Water deeply 1-2 times per week (1 inch total)
- Avoid fertilizing cool-season grasses in peak heat
- Scout for grubs and treat if >10 per sq ft
Fall
- Overseed warm-season lawns if thinning
- Apply fall fertilizer (highest N application for cool-season)
- Continue mowing until growth stops
- Rake or mulch leaves to prevent smothering
Winter
- Apply pre-emergent for winter weeds
- Service mower and sharpen blades
- Plan spring soil amendments based on fall test
- Overseed with ryegrass for winter color
Watering Deficit Calculator
Monthly Deficit
0.0"
inches of water
Monthly Water
0
gallons
Estimated Monthly Cost
$0.00
at $0.008/gallon average
Estimates based on 61" annual precipitation and estimated evapotranspiration. Actual costs vary by local water rates.
Common Lawn Problems in Clackamas County
Excess Moisture & Fungal Disease
High annual rainfall (61 inches) increases risk of fungal diseases like brown patch and dollar spot. Ensure good drainage and avoid overwatering.
Persistent Drought Conditions
Clackamas County experienced drought conditions for 29 of the past 52 weeks. Prioritize water-efficient grasses and consider reducing lawn area.
Learn more about regional lawn challenges at The Lawn Report.
Want detailed soil composition, drainage classes, and soil series data? View soil details on SoilByCounty.com
Data sourced from USDA SSURGO, NOAA Climate Normals (1991-2020), USDA Plant Hardiness Zone Map, and US Drought Monitor. Lawn difficulty scores and grass recommendations are estimates for informational purposes only.
Explore more data for Clackamas County