Soil Types in Arkansas

Arkansas has 521 zip codes in our database. The most common soil type is Loam, found in 0% of the state. Understanding your local soil type helps you choose the right plants and amendments for your garden.

Arkansas spans USDA hardiness zones 7a through 8b. Your hardiness zone determines which perennial plants will survive winter in your area. Enter your zip code above to find your exact zone and get personalized planting recommendations.

Arkansas straddles two major physiographic regions, creating a split personality in its soils. The western half belongs to the Ozark Plateau and Ouachita Mountains, where thin, rocky soils form over limestone, sandstone, and shale. These upland soils tend toward acidity and drain quickly, making them suitable for pasture and timber but challenging for row crops. The eastern half is the Mississippi Alluvial Plain — the famed Delta — where centuries of river flooding deposited deep, rich silt and clay. These Delta soils rank among the most productive in the world for rice, soybeans, and cotton. Stuttgart sandy loam, the state soil of Arkansas, reflects this alluvial heritage. Between these regions, the Arkansas River Valley contains a mix of bottomland soils and terrace deposits that support diverse agriculture.

Arkansas has a moderate growing season that varies about 40 days from north to south. Northwestern counties around Fayetteville see their last spring frost near April 10-15 and first fall frost by mid-October, providing roughly 185 growing days. Central Arkansas near Little Rock enjoys a longer window: last frost around March 20, first frost in early November, yielding about 230 days. The southern Delta region near Texarkana stretches to 240-250 frost-free days. Summer humidity is intense statewide, which benefits moisture-loving crops but also promotes fungal diseases. Fall gardening is highly productive in Arkansas — September plantings of broccoli, cabbage, and lettuce produce well through November.

Arkansas is the leading rice-producing state in the nation, thanks to the Delta's heavy clay soils that hold water in flooded paddies. The same region excels at soybeans and cotton. For home gardeners, tomatoes, okra, black-eyed peas, watermelon, and sweet corn are summer staples. The Ozark region's well-drained acidic soils are ideal for blueberries and blackberries — Arkansas is famous for its thornless blackberry varieties developed at the University of Arkansas. Apple orchards dot the northwest highlands. Peach trees perform well in the central part of the state. Native pecans grow throughout Arkansas, particularly along river bottomlands where deep alluvial soils provide the nutrients and moisture these large trees demand.

The University of Arkansas Division of Agriculture operates a soil testing laboratory that processes samples submitted through county extension offices. Basic tests are free or low-cost for Arkansas residents. Ozark region soils typically need lime to raise pH from the 5.0-5.5 range up to 6.0-6.5 for vegetable production. Delta soils may need different attention: heavy clay benefits from gypsum to improve structure without changing pH, plus cover crops like winter wheat or crimson clover to prevent the compaction that heavy machinery causes. Adding organic matter is universally beneficial across Arkansas — compost, leaves, and aged manure improve both the drainage of clay soils and the water retention of sandy upland soils.