Grafton County Soil Data
Grafton County, New Hampshire
USDA SSURGO / PHZMAvg pH
4.7
Texture
Loam
Drainage
N/A
Organic Matter
36.4%
Hydrologic Group
N/A
Data Story
About Soil in Grafton County, New Hampshire
Balanced Acidity in the River Valley
Grafton County features a soil pH of 4.67, which is more alkaline than the New Hampshire average of 4.24. While still below the national median of 6.5, it offers a more hospitable environment for many crops. This slight advantage helps the county maintain a strong soil score of 66.7.
Loamy Sand with Minimal Clay
The soil contains 36.3% sand and 25.2% silt, but only 4.0% clay. This composition means the soil is highly workable and allows for deep root penetration. It strikes a great balance between structural stability and ease of cultivation.
Superior Water Retention and Organic Richness
Grafton's organic matter reaches 36.41%, well above the state average of 32.63%. Its available water capacity of 0.239 in/in is among the highest in the region. These metrics indicate a very fertile landscape capable of sustaining high-yield gardens.
High Performance Water Storage
The 0.239 available water capacity suggests excellent drought resistance for local crops. While the specific drainage class isn't listed, the low clay content prevents the soil from becoming heavy and waterlogged. This makes it an ideal choice for both intensive farming and residential landscaping.
Success in Hardiness Zone 5a
Zone 5a provides a classic New England growing environment for hardy perennials and shrubs. You can expect fantastic results with leafy greens, brassicas, and berries in this high-fertility soil. The high water capacity means you can spend less time watering and more time harvesting.
Soil Composition
Soil pH
Soil Series
Detailed soil series data not yet available for this county.
Hydrologic Group
Hydrologic group data not available.
Drainage Class
Drainage class data not available.
Soil Profile
Dominant texture: Loam
Typical soil profile. Actual depths vary by location.
USDA Soil Orders
Acidic Soil Detected
Your county's average pH is 4.7. These products help balance soil pH for healthier grass.
Browse Soil AmendmentsFrequently Asked Questions
What type of soil does Grafton County have?
Grafton County's soil is classified as Loam. This indicates the relative proportions of sand, silt, and clay — 36% sand, 25% silt, and 4% clay. Loamy soils hold moisture well and support a wide range of plants.
Is Grafton County's soil acidic or alkaline?
Grafton County's soil has a low pH of 4.7, which is strongly acidic. Acidic soils benefit from lime applications to raise pH and improve nutrient availability.
What is the drainage class for Grafton County?
Drainage class data is not currently available for Grafton County.
What crops or plants grow well in Grafton County's soil?
Based on Grafton County's Loam texture, pH of 4.7, and drainage class, the soil is well suited for acid-loving plants like blueberries and azaleas, row crops and vegetable gardens.
What USDA soil order is found in Grafton County?
The dominant USDA soil order for Grafton County is not currently available in our dataset.
Soil & Planting Advisory: Grafton County
Soil Verdict
Grafton County is in USDA hardiness zone 5a, a cold climate zone. where winter lows can reach -20°F. Freeze-thaw cycles are moderate; soil biology slows in winter but recovers reliably in spring, supporting a broad range of plants.
Planting Guidance
A wide plant palette is possible: deciduous trees, most shrubs, cool-season vegetables, and many perennials thrive here. With extreme winter lows, any marginally hardy plants need heavy mulch and wind protection. Always match plant selections to the specific microclimate of your property — low spots, slopes, and wind exposure can shift effective hardiness by half a zone.
Soil Implications
Moderate freeze-thaw cycles naturally aerate the soil but can also cause compaction in clay-heavy areas; annual core aeration is beneficial. Organic matter amendments decompose at a moderate pace — aim for 3-5% organic content for optimal fertility. When soil temperatures drop below freezing, microbial nitrogen cycling stops; spring fertilization is more effective than late-fall application.
Regional Context
Grafton County closely matches the New Hampshire average hardiness conditions. The zone range of 4b-5b within the county means soil and planting decisions should account for local elevation and topography.
Planning your lawn? View lawn care data for Grafton County on LawnByCounty.com →
Other Counties in New Hampshire
Soil data sourced from USDA SSURGO via Soil Data Access. Data is informational only and should not be used as a substitute for on-site soil testing. Contact your local NRCS office for site-specific soil information.