March 24, 2021
By Ken Duke
Editor's Note: This timely article is featured in the West edition of the April issue of Game & Fish Magazine, currently on sale at newsstands across the country. Learn more about the April issue. Interested in a subscription ($8 annual)? Click here.
Each spring, adult largemouths go through three critical reproductive phases: pre-spawn, spawn and post-spawn. While winter and summer are fairly distinct and uniform periods of time, the springtime spawn phases for largemouths are more nebulous and overlap considerably.
Timing for the spawn varies by latitude and elevation. And, depending on late-spring weather, the spawn’s timing in one lake can vary slightly from year to year. By breaking the spawn phases down and taking a deep dive into each of them, we not only gain a better understanding of how bass behave in these three phases, we ultimately catch more fish. After all, any time we hit the water—regardless of the time the year—identifying the proper seasonal patterns is the first step to success. It tells us where to start, and nothing’s more important than that.
Whereas July and August are clearly summer and December and January are obviously winter, once temperatures warm into the low 50s, the pre-spawn is on and the line between it and the spawn proper can quickly start to blur. By now, many if not most bass have left their winter holding areas—usually deep, vertical structure—and moved to main-lake points, secondary points and the first drop-offs at the edges of flats. This happens first in the northwestern sections of lakes because the angle of the sun warms those areas faster than others at this time of year. And if you look hard enough, you’ll almost certainly find some bass already spawning in protected flats with the water temperature still in the mid-50s, especially if this occurs after a prolonged warming trend or on a full moon.
The lesson here is that the lines of demarcation between pre-spawn, spawn and post-spawn are unclear. With respect to bass behavior, the whole period should be viewed as a bell curve, with low sides representing low numbers of spawning bass on the left (early spawners) and right (late spawners). In the middle is the peak of the spawn. In the Southwest, that bell curve typically begins in late February and the right side occurs in May. March and April are when most of the bass spawn in a typical year.
The farther north we go, the more that bell curve shifts to the later months. As we get into Washington and Oregon and the Rocky Mountain states, the left side of the curve begins in March and the right side is usually June or even July. April and May are the peak spawning months, depending upon prevailing weather patterns. With unseasonably warm or cold weather, the bell curve shifts to the left or right, respectively.
As our bass fishing efforts move north during the three spawning seasons, the bell curve also becomes narrower. While these spawn periods often last for several months in the extreme South, they’ll be compressed into just a few weeks near the Canadian border. The farther north you fish, the fewer opportunities you’ll have to hit one of the three spawning phases, but the more intense and defined those phases will be.
Once water temperatures begin to warm following winter lows, bass take notice and the pre-spawn period begins. Signs can be as subtle as finding bass near shallow cover and structure—and away from the vertical structure associated with winter holding areas—to more obvious signs on the fish themselves: You may catch an occasional male bass in or near traditional spawning areas that has a worn and bloody tail from sweeping its nesting areas clean.
Typically, the first bass to spawn each season are among the biggest. Legendary underwater filmmaker Glen Lau surmises that the bigger bass can handle the cold better and are less impacted by it.
The period when many or most bass are in pre-spawn mode is a great time to be on the water. These fish tend to be active and feed heavily in preparation for the mating ritual. They move shallow and eat more—both habits making them more vulnerable to anglers. By targeting cover and structure near protected bays and coves where they’re likely to spawn, you could hit the mother lode.
Lure selection at this time is less critical than proper location. As tournament standout Edwin Evers puts it, “The wrong bait in the right place will catch them every time.”
That said, choose lures based on their ability to cover water, navigate any cover and imitate the lake’s forage base. Examples include crankbaits, swimbaits and suspending jerkbaits. Weighted worms are good at probing structure like drop-offs or channel edges where bass stack up as they stage before heading shallow.
Your first job is to figure out whether the pre-spawn fish are still staging on drop-offs near deep water, or have progressed to the point that they are actively feeding in shallow water. That’s why you use baits that cover a lot of water. If your day starts at dawn or under low-light conditions, start shallow, favoring locations with rock or wood cover that would allow active bass to ambush forage fish.
If you find the fish on predictable types of shallow cover (blowdowns, stumps or weed lines) or structure (rocks and shallow creek channels), you can slow down and fish that cover more carefully with weightless soft-plastic stickbaits like Senkos or Yum Dingers that appeal to fish because they look tasty and are easy to catch.
If the fish are not shallow—or time of year and cold water suggest it’s unlikely they’ve gone shallow yet—try fishing deeper staging areas along creek channels, ledges and points. You’re looking for places that deep bass can use structure to ambush prey. The best structure to probe will be close to the to shallow feeding and spanwing flats that the bass will eventually move into as water warms.
The depth of pre-spawn and spawning fish is heavily influenced by water clarity. The dirtier the water, the shallower they’ll spawn. Eggs need the warmth of the sun to incubate and hatch. If water visibility is measured in mere inches, you can focus your efforts in just a few feet of water. But if the water is extremely clear, it’s not unheard of for bass to spawn in 15- or even 20-foot depths.
And while the moon phase is important, a full moon does more to concentrate spawning activity than to control it. You’ll likely find large waves of bass spawning around the full moon, but a thorough search of a spawning area can reveal them during other moon phases as well.
In general, however, Lau believes the key period in this annual process begins six days before the full moon once water temperatures reach the 50s. It will likely peak when temperatures are in the 60s and continue for the final stragglers until temperatures are in the 70s. Lau has spent more than 13,000 hours underwater studying the largemouth, and has observed thousands of spawning bass.
“At six days before the full moon, female largemouths will congregate around a log or other piece of cover, which they rub and bump their bellies against,” Lau says. “I believe they’re loosening the eggs they’re carrying so they’ll be easier to lay. This bumping activity takes place for about three days.”
While the females are readying themselves for the spawn, male bass are starting to build the nests. They’ll often start to build a nest by fanning in an area, but stop if they find too much mud or silt, which can suffocate the eggs and prevent them from hatching. While the male is building his nest, the female will wait nearby. Sometimes the male will drive a female to his nest by nipping, biting and pushing her to the exact spot where he wants the eggs to be laid.
After the female makes several passes over the nest to deposit her eggs, the male will fertilize them with his milt. The egg-laying process will often give the female a bloody tail. This is caused by the way she scoots through the nest to deposit her eggs, not from fanning the nest. Fanning is a male thing.
“After a female has deposited all of her eggs,” Lau says, “she establishes a wide perimeter around the nest and will hold there for up to five days, though it’s often tough to see that she’s present. Eventually, the female will retreat to deep water to recuperate for anywhere from two days to a full week. She feeds and moves very little during this time.”
Once the eggs are laid and before they hatch, it’s usually necessary to antagonize the bass by representing a threat to the nest in order to get a strike. They won’t actively feed, but they will often protect the bed by attacking predators or picking them up off the nest and carrying them away. Bed fishing in that way is a controversial topic among anglers, but it may present our best opportunity to catch the biggest fish of the year.
When you fish beds, choose a bait that looks dangerous to eggs, such as a salamander, crawdad or scavanging small fish. Move that bait into the nest and let it rest on the bottom, moving it just subtly enough that it looks like it is searching for eggs to eat. You want the bait to anger the bass. Some color on the bait will help you see whether the bass picks it up—the bite may be too soft to feel.
Bass movement after the spawn is predominantly the reverse of pre-spawn movement. Many females head for the first structure break leading to deeper water—creek channels, ledges and points. Here they rest for a few days, but then begin to feed more actively as they recover from the spawn.
Again, use search baits until you find what depth and structure the bass are favoring. Though bass feed less immediately after the spawn, it’s likely that you’ll be fishing over some fish that have recovered and are active since not all bass spawn at the same time. In fact, some of the active fish may be pre-spawn bass holding right next to bass that have already recovered from the spawn.
Anglers who are patient enough to figure out where most of the active fish are will catch more bass at any stage of the spawn. For every bass hooked, note critical variables: depth, structure, temperature, size of fish and, of course, what bait they bit. Build an evidence set of where the active fish are, and you’ll fill your livewell.
SEEING IS BELIEVING
Can’t find the bass beds? Try an aquascope.
If you’re struggling to see what’s under the water with your own eyes, you might try an aquascope, also known as a bathyscope. The Flogger from LureCraft is a popular version that looks a lot like a funnel or old-fashioned megaphone. You simply place the large end against the water’s surface and look through the small end as though it’s a telescope. This reduces glare and surface disturbance to give you an unimpeded view of what’s going on beneath the waves.
Of course, the Flogger won’t help much in dingy water, and when the beds are extremely shallow you won’t need it, but an aquascope can offer a much-improved perspective on the spawning process, especially when the bass are deep enough that having a boat right above them doesn’t push them off the bed.