Best Soil for Gardening in Iowa

In Iowa, the most good growing ground is in O'Brien County, Iowa, where 96% of the land rates Class I–II. Jackson County, Iowa is at the other end with 14%.

USDA grades every mapped soil into a land capability class from I to VIII, for growing crops without irrigation. Class I and II soils have few or moderate limitations: deep, workable, enough water. Classes III and IV can be farmed with care. Classes V through VIII are steep, stony, wet, shallow, or too dry, and are usually left to grass, range or woods.

We rank by the share of land in Class I–II. One thing to know: the grade includes rainfall. In dry states much of the land rates Class VI or VII simply because crops need watering there, so a watered garden on that ground can still do well. Look up your address for the pH, texture and water-holding that matter for a backyard bed.