The best method of determining this period of bluegill spawning activity is water temperatiure. This period usually corresponds closely with Memorial Day in Iowa. Fish a week or two before and after this holiday, and you will center the major spawning activity. It is often easy to spot the saucer-shaped depressions because bluegill build their nests in shallow water very close to shore. Carefully search water from 2 to 6 feet deep and locate a spawning bed.
Male bluegills guarding nests are woefully easy to catch.
Although the same factors govern the spawning habits of bluegill, there may be great differences depending on habitat. Here they find habitats where the constant current will not disturb the nest. Current is not a major factor in natural lakes, ponds, and reservoirs, where males build their nests in shallow bays or along protected shorelines. In these habitats bluegill spawn among sticks, stumps, or thinly-spaced vegetation. A shallow flat adjacent to a flooded creek channel is also a good place to find spawning bluegill.